Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3 by Various

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Title: Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3
"Brescia" to "Bulgaria"

Author: Various

Release Date: April 13, 2007 [EBook #19699]

Language: English

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Transcriber's note: A few typographical errors have been corrected: they
are listed at the end of the text. Volume and page numbers have been
incorporated into the text of each page as: v.04 p.0001.

[v.04 p.0498] BRÉQUIGNY, LOUIS GEORGE OUDARD FEUDRIX DE (_continued from
part 2_)

... volumes x.-xiv., the preface to vol. xi. containing important
researches into the French communes. To the _Table chronologique des
diplômes, chartes, lettres, et actes imprimés concernant l'histoire de
France_ he contributed three volumes in collaboration with Mouchet
(1769-1783). Charged with the supervision of a large collection of
documents bearing on French history, analogous to Rymer's _Foedera_, he
published the first volume (_Diplomatat. Chartae_, &c., 1791). The
Revolution interrupted him in his collection of _Mémoires concernant
l'histoire, les sciences, les lettres, et les arts des Chinois_, begun in
1776 at the instance of the minister Bertin, when fifteen volumes had
appeared.

See the note on Bréquigny at the end of vol. i. of the _Mémoires de
l'Académie des Inscriptions_ (1808); the Introduction to vol. iv. of the
_Table chronologique des diplômes_ (1836); Champollion-Figeac's preface to
the _Lettres des rois et reines_; the _Comité des travaux historiques_, by
X. Charmes, vol. i. _passim_; N. Oursel, _Nouvelle biographie normande_
(1886); and the _Catalogue des manuscrits des collections Duchesne et
Bréquigny_ (in the Bibliothèque Nationale), by René Poupardin (1905).

(C. B.*)

BRESCIA (anc. _Brixia_), a city and episcopal see of Lombardy, Italy, the
capital of the province of Brescia, finely situated at the foot of the
Alps, 52 m. E. of Milan and 40 m. W. of Verona by rail. Pop. (1901) town,
42,495; commune, 72,731. The plan of the city is rectangular, and the
streets intersect at right angles, a peculiarity handed down from Roman
times, though the area enclosed by the medieval walls is larger than that
of the Roman town, which occupied the eastern portion of the present one.
The Piazza del Museo marks the site of the forum, and the museum on its
north side is ensconced in a Corinthian temple with three _cellae_, by some
attributed to Hercules, but more probably the Capitolium of the city,
erected by Vespasian in A.D. 73 (if the inscription really belongs to the
building; cf. Th. Mommsen in _Corp. Inscrip. Lat._ v. No. 4312, Berlin,
1872), and excavated in 1823. It contains a famous bronze statue of
Victory, found in 1826. Scanty remains of a building on the south side of
the forum, called the _curia_, but which may be a basilica, and of the
theatre, on the east of the temple, still exist.

Brescia contains many interesting medieval buildings. The castle, at the
north-east angle of the town, commands a fine view. It is now a military
prison. The old cathedral is a round domed structure of the 10th (?)
century erected over an early Christian basilica, which has forty-two
ancient columns; and the Broletto, adjoining the new cathedral (a building
of 1604) on the north, is a massive building of the 12th and 13th centuries
(the original town hall, now the prefecture and law courts), with a lofty
tower. There are also remains of the convent of S. Salvatore, founded by
Desiderius, king of Lombardy, including three churches, two of which now
contain the fine medieval museum, which possesses good ivories. The church
of S. Francesco has a Gothic façade and cloisters. There are also some good
Renaissance palaces and other buildings, including the Municipio, begun in
1492 and completed by Jacopo Sansovino in 1554-1574. This is a magnificent
structure, with fine ornamentation. The church of S. Maria dei Miracoli
(1488-1523) is also noteworthy for its general effect and for the richness
of its details, especially of the reliefs on the façade. Many other
churches, and the picture gallery (Galleria Martinengo), contain fine works
of the painters of the Brescian school, Alessandro Bonvicino (generally
known as Moretto), Girolamo Romanino and Moretto's pupil, Giovanni Battista
Moroni. The Biblioteca Queriniana contains early MSS., a 14th-century MS.
of Dante, &c., and some rare incunabula. The city is well supplied with
water, and has no less than seventy-two public fountains. Brescia has
considerable factories of iron ware, particularly fire-arms and weapons
(one of the government small arms factories being situated here), also of
woollens, linens and silks, matches, candles, &c. The stone quarries of
Mazzano, 8 m. east of Brescia, supplied material for the monument to Victor
Emmanuel II. and other buildings in Rome. Brescia is situated on the main
railway line between Milan and Verona, and has branch railways to Iseo,
Parma, Cremona and (via Rovato) to Bergamo, and steam tramways to Mantua,
Soncino, Ponte Toscolano and Cardone Valtrompia.

The ancient Celtic Brixia, a town of the Cenomani, became Roman in 225
B.C., when the Cenomani submitted to Rome. Augustus founded a civil (not a
military) colony here in 27 B.C., and he and Tiberius constructed an
aqueduct to supply it. In 452 it was plundered by Attila, but was the seat
of a duchy in the Lombard period. From 1167 it was one of the most active
members of the Lombard League. In 1258 it fell into the hands of Eccelino
of Verona, and belonged to the Scaligers (della Scala) until 1421, when it
came under the Visconti of Milan, and in 1426 under Venice. Early in the
16th century it was one of the wealthiest cities of Lombardy, but has never
recovered from its sack by the French under Gaston de Foix in 1512. It
belonged to Venice until 1797, when it came under Austrian dominion; it
revolted in 1848, and again in 1849, being the only Lombard town to rally
to Charles Albert in the latter year, but was taken after ten days'
obstinate street fighting by the Austrians under Haynau.

See _Museo Bresciano Illustrato_ (Brescia, 1838).

(T. AS.)

BRESLAU (Polish _Wraclaw_), a city of Germany, capital of the Prussian
province of Silesia, and an episcopal see, situated in a wide and fertile
plain on both banks of the navigable Oder, 350 m. from its mouth, at the
influx of the Ohle, and 202 m. from Berlin on the railway to Vienna. Pop.
(1867) 171,926; (1880) 272,912; (1885) 299,640; (1890) 335,186; (1905)
470,751, about 60% being Protestants, 35% Roman Catholics and nearly 5%
Jews. The Oder, which here breaks into several arms, divides the city into
two unequal halves, crossed by numerous bridges. The larger portion, on the
left bank, includes the old or inner town, surrounded by beautiful
promenades, on the site of the ramparts, dismantled after 1813, from an
eminence within which, the Liebichs Höhe, a fine view is obtained of the
surrounding country. Outside, as well as across the Oder, lies the new town
with extensive suburbs, containing, especially in the Schweidnitz quarter
in the south, and the Oder quarter in the north, many handsome streets and
spacious squares. The inner town, in contrast to the suburbs, still retains
with its narrow streets much of its ancient characters, and contains
several medieval buildings, both religious and secular, of great beauty and
interest. The cathedral, dedicated to St John the Baptist, was begun in
1148 and completed at the close of the 15th century, enlarged in the 17th
and 18th centuries, and restored between 1873 and 1875; it is rich in
notable treasures, especially the high altar of beaten silver, and in
beautiful paintings and sculptures. The Kreuzkirche (church of the Holy
Cross), dating from the 13th and 14th centuries, is an interesting brick
building, remarkable for its stained glass and its historical monuments,
among which is the tomb of Henry IV., duke of Silesia. The Sandkirche, so
called from its dedication to Our Lady on the Sand, dates from the 14th
century, and was until 1810 the church of the Augustinian canons. The
Dorotheenor Minoritenkirche, remarkable for its high-pitched roof, was
founded by the emperor Charles IV. in 1351. These are the most notable of
the Roman Catholic churches. Of the Evangelical churches the most important
is that of St Elizabeth, founded about 1250, rebuilt in the 14th and 15th
centuries, and restored in 1857. Its lofty tower contains the largest bell
in Silesia, and the church possesses a celebrated organ, fine stained
glass, a magnificent stone pyx (erected in 1455) over 52 ft. high, and
portraits of Luther and Melanchthon by Lucas Cranach. The church of St Mary
Magdalen, built in the 14th century on the model of the cathedral, has two
lofty Gothic towers connected by a bridge, and is interesting as having
been the church in which, in 1523, the reformation in Silesia was first
proclaimed. Other noteworthy ecclesiastical buildings are the graceful
Gothic church of St Michael built in 1871, the bishop's palace and the
Jewish synagogue, the finest in Germany after that in Berlin.

The business streets of the city converge upon the Ring, the market square,
in which is the town-hall, a fine Gothic building, begun in the middle of
the 14th and completed in the 16th century. Within is the Fürstensaal, in
which the diets of Silesia were formerly held, while beneath is the famous
Schweidnitzer Keller, used continuously since 1355 as a beer and wine
house. [v.04 p.0499] The university, a spacious Gothic building facing the
Oder, is a striking edifice. It was built (1728-1736) as a college by the
Jesuits, on the site of the former imperial castle presented to them by the
emperor Leopold I., and contains a magnificent hall (Aula Leopoldina),
richly ornamented with frescoes and capable of holding 1200 persons.
Breslau possesses a large number of other important public buildings: the
Stadthaus (civic hall), the royal palace, the government offices (a
handsome pile erected in 1887), the provincial House of Assembly, the
municipal archives, the courts of law, the Silesian museum of arts and
crafts and antiquities, stored in the former assembly hall of the estates
(Ständehaus), which was rebuilt for the purpose, the museum of fine arts,
the exchange, the Stadt and Lobe theatres, the post office and central
railway station. There are also numerous hospitals and schools. Breslau is
exceedingly rich in fine monuments; the most noteworthy being the
equestrian statues of Frederick the Great and Frederick William III., both
by Kiss; the statue of Blücher by Rauch; a marble statue of General
Tauentzien by Langhans and Schadow; a bronze statue of Karl Gottlieb Svarez
(1746-1798), the Prussian jurist, a monument to Schleiermacher, born here
in 1768, and statues of the emperor William I., Bismarck and Moltke. There
are also several handsome fountains. Foremost among the educational
establishments stands the university, founded in 1702 by the emperor
Leopold I. as a Jesuit college, and greatly extended by the incorporation
of the university of Frankfort-on-Oder in 1811. Its library contains
306,000 volumes and 4000 MSS., and has in the so-called _Bibliotheca
Habichtiana_ a valuable collection of oriental literature. Among its
auxiliary establishments are botanical gardens, an observatory, and
anatomical, physiological and kindred institutions. There are eight
classical and four modern schools, two higher girls' schools, a Roman
Catholic normal school, a Jewish theological seminary, a school of arts and
crafts, and numerous literary and charitable foundations. It is, however,
as a commercial and industrial city that Breslau is most widely known. Its
situation, close to the extensive coal and iron fields of Upper Silesia, in
proximity to the Austrian and Russian frontiers, at the centre of a network
of railways directly communicating both with these countries and with the
chief towns of northern and central Germany, and on a deep waterway
connecting with the Elbe and the Vistula, facilitates its very considerable
transit and export trade in the products of the province and of the
neighbouring countries. These embrace coal, sugar, cereals, spirits,
petroleum and timber. The local industries comprise machinery and tools,
railway and tramway carriages, furniture, cast-iron goods, gold and silver
work, carpets, furs, cloth and cottons, paper, musical instruments, glass
and china. Breslau is the headquarters of the VI. German army corps and
contains a large garrison of troops of all arms.

_History._--Breslau (Lat. _Vratislavia_) is first mentioned by the
chronicler Thietmar, bishop of Merseburg, in A.D. 1000, and was probably
founded some years before this date. Early in the 11th century it was made
the seat of a bishop, and after having formed part of Poland, became the
capital of an independent duchy in 1163. Destroyed by the Mongols in 1241,
it soon recovered its former prosperity and received a large influx of
German colonists. The bishop obtained the title of a prince of the Empire
in 1290.[1] When Henry VI., the last duke of Breslau, died in 1335, the
city came by purchase to John, king of Bohemia, whose successors retained
it until about 1460. The Bohemian kings bestowed various privileges on
Breslau, which soon began to extend its commerce in all directions, while
owing to increasing wealth the citizens took up a more independent
attitude. Disliking the Hussites, Breslau placed itself under the
protection of Pope Pius II. in 1463, and a few years afterwards came under
the rule of the Hungarian king, Matthias Corvinus. After his death in 1490
it again became subject to Bohemia, passing with the rest of Silesia to the
Habsburgs when in 1526 Ferdinand, afterwards emperor, was chosen king of
Bohemia. Having passed almost undisturbed through the periods of the
Reformation and the Thirty Years' War, Breslau was compelled to own the
authority of Frederick the Great in 1741. It was, however, recovered by the
Austrians in 1757, but was regained by Frederick after his victory at
Leuthen in the same year, and has since belonged to Prussia, although it
was held for a few days by the French in 1807 after the battle of Jena, and
again in 1813 after the battle of Bautzen. The sites of the fortifications,
dismantled by the French in 1807, were given to the civic authorities by
King Frederick William III., and converted into promenades. In March 1813
this monarch issued from Breslau his stirring appeals to the Prussians, _An
mein Volk_ and _An mein Kriegesheer_, and the city was the centre of the
Prussian preparations for the campaign which ended at Leipzig. After the
Prussian victory at Sadowa in 1866, William I. made a triumphant and
complimentary entry into the city, which since the days of Frederick the
Great has been only less loyal to the royal house than Berlin itself.

See Bürkner and Stein, _Geschichte der Stadt Breslau_ (Bresl. 1851-1853);
J-Stein, _Geschichte der Stadt Breslau im 19ten Jahrhundert_ (1884); O
Frenzel, _Breslauer Stadtbuch_ ("Codex dipl. Silisiae," vol. ii. 1882);
Luchs, _Breslau, ein Führer durch die Stadt_ (12th ed., Bresl. 1904).

[1] In 1195 Jaroslaw, son of Boleslaus I. of Lower Silesia, who became
bishop of Breslau in 1198, inherited the duchy of Neisse, which at his
death (1201) he bequeathed to his successors in the see. The Austrian part
of Neisse still belongs to the bishop of Breslau, who also still bears the
title of prince bishop.

BRESSANT, JEAN BAPTISTE PROSPER (1815-1886), French actor, was born at
Chalon-sur-Saône on the 23rd of October 1815, and began his stage career at
the Variétés in Paris in 1833. In 1838 he went to the French theatre at St
Petersburg, where for eight years he played important parts with
ever-increasing reputation. His success was confirmed at the Gymnase when
he returned to Paris in 1846, and he made his _début_ at the Comédie
Française as a full-fledged _sociétaire_ in 1854. From playing the ardent
young lover, he turned to leading rôles both in modern plays and in the
classical répertoire. His Richelieu in _Mlle de Belle-Isle_, his Octave in
Alfred de Musset's _Les Caprices de Marianne_, and his appearance in de
Musset's _Il faut qu'une porte soit ouverte ou fermée_ and _Un caprice_
were followed by _Tartuffe_, _Le Misanthrope_ and _Don Juan_. Bressant
retired in 1875, and died on the 23rd of January 1886. During his
professorship at the Conservatoire, Mounet-Sully was one of his pupils.

BRESSE, a district of eastern France embracing portions of the departments
of Ain, Saône-et-Loire and Jura. The Bresse extends from the Dombes on the
south to the river Doubs on the north, and from the Saône eastwards to the
Jura, measuring some 60 m. in the former, and 20 m. in the latter
direction. It is a plain varying from 600 to 800 ft. above the sea, with
few eminences and a slight inclination westwards. Heaths and coppice
alternate with pastures and arable land; pools and marshes are numerous,
especially in the north. Its chief rivers are the Veyle, the Reyssouze and
the Seille, all tributaries of the Saône. The soil is a gravelly clay but
moderately fertile, and cattle-raising is largely carried on. The region
is, however, more especially celebrated for its table poultry. The
inhabitants preserve a distinctive but almost obsolete costume, with a
curious head-dress. The Bresse proper, called the _Bresse Bressane_,
comprises the northern portion of the department of Ain. The greater part
of the district belonged in the middle ages to the lords of Bâgé, from whom
it passed in 1272 to the house of Savoy. It was not till the first half of
the 15th century that the province, with Bourg as its capital, was founded
as such. In 1601 it was ceded to France by the treaty of Lyons, after which
it formed (together with the province of Bugey) first a separate government
and afterwards part of the government of Burgundy.

BRESSUIRE, a town of western France, capital of an arrondissement in the
department of Deux-Sèvres, 48 m. N. of Niort by rail. Pop. (1906) 4561. The
town is situated on an eminence overlooking the Dolo, a tributary of the
Argenton. It is the centre of a cattle-rearing and agricultural region, and
has important markets; the manufacture of wooden type and woollen goods is
carried on. Bressuire has two buildings of interest: the church of
Notre-Dame, which, dating chiefly from the 12th and 15th centuries, has an
imposing tower of the Renaissance period; and the castle, built by the
lords of [v.04 p.0500] Beaumont, vassals of the viscount of Thouars. The
latter is now in ruins, and a portion of the site is occupied by a modern
château, but an inner and outer line of fortifications are still to be
seen. The whole forms the finest assemblage of feudal ruins in Poitou.
Bressuire is the seat of a sub-prefect and has a tribunal of first
instance. Among the disasters suffered at various times by the town, its
capture from the English and subsequent pillage by French troops under du
Guesclin in 1370 is the most memorable.

BREST, a fortified seaport of western France, capital of an arrondissement
in the department of Finistère, 155 m. W.N.W. of Rennes by rail. Population
(1906) town, 71,163; commune, 85,294. It is situated to the north of a
magnificent landlocked bay, and occupies the slopes of two hills divided by
the river Penfeld,--the part of the town on the left bank being regarded as
Brest proper, while the part on the right is known as Recouvrance. There
are also extensive suburbs to the east of the town. The hill-sides are in
some places so steep that the ascent from the lower to the upper town has
to be effected by flights of steps and the second or third storey of one
house is often on a level with the ground storey of the next. The chief
street of Brest bears the name of rue de Siam, in honour of the Siamese
embassy sent to Louis XIV., and terminates at the remarkable swing-bridge,
constructed in 1861, which crosses the mouth of the Penfeld. Running along
the shore to the south of the town is the Cours d'Ajot, one of the finest
promenades of its kind in France, named after the engineer who constructed
it. It is planted with trees and adorned with marble statues of Neptune and
Abundance by Antoine Coysevox. The castle with its donjon and seven towers
(12th to the 16th centuries), commanding the entrance to the river, is the
only interesting building in the town. Brest is the capital of one of the
five naval arrondissements of France. The naval port, which is in great
part excavated in the rock, extends along both banks of the Penfeld; it
comprises gun-foundries and workshops, magazines, shipbuilding yards and
repairing docks, and employs about 7000 workmen. There are also large naval
barracks, training ships and naval schools of various kinds, and an
important naval hospital. Brest is the seat of a sub-prefect and has
tribunals of first instance and of commerce, a chamber of commerce, a board
of trade-arbitrators, two naval tribunals, and a tribunal of maritime
commerce. There are also lycées for boys and girls and a school of commerce
and industry. The commercial port, which is separated from the town itself
by the Cours d'Ajot, comprises a tidal port with docks and an outer
harbour; it is protected by jetties to the east and west and by a
breakwater on the south. In 1905 the number of vessels entered was 202 with
a tonnage of 67,755, and cleared 160 with a tonnage of 61,012. The total
value of the imports in 1905 was £244,000. The chief were wine, coal,
timber, mineral tar, fertilizers and lobsters and crayfish. Exports, of
which the chief were wheat-flour, fruit and superphosphates, were valued at
£40,000. Besides its sardine and mackerel fishing industry, the town has
flour-mills, breweries, foundries, forges, engineering works, and
manufactures of blocks, candles, chemicals (from sea-weed), boots, shoes
and linen. Brest communicates by submarine cable with America and French
West Africa. The roadstead consists of a deep indentation with a maximum
length of 14 m. and an average width of 4 m., the mouth being barred by the
peninsula of Quélern, leaving a passage from 1 to 2 m. broad, known as the
Goulet. The outline of the bay is broken by numerous smaller bays or arms,
formed by the embouchures of streams, the most important being the Anse de
Quélern, the Anse de Poulmie, and the mouths of the Châteaulin and the
Landerneau. Brest is a fortress of the first class. The fortifications of
the town and the harbour fall into four groups: (1) the very numerous forts
and batteries guarding the approaches to and the channel of the Goulet; (2)
the batteries and forts directed upon the roads; (3) a group of works
preventing access to the peninsula of Quélern and commanding the ground to
the south of the peninsula from which many of the works of group (2) could
be taken in reverse; (4) the defences of Brest itself, consisting of an
old-fashioned _enceinte_ possessing little military value and a chain of
detached forts to the west of the town.

Nothing definite is known of Brest till about 1240, when it was ceded by a
count of Léon to John I., duke of Brittany. In 1342 John of Montfort gave
it up to the English, and it did not finally leave their hands till 1397.
Its medieval importance was great enough to give rise to the saying, "He is
not duke of Brittany who is not lord of Brest." By the marriage of Francis
I. with Claude, daughter of Anne of Brittany, Brest with the rest of the
duchy definitely passed to the French crown. The advantages of the
situation for a seaport town were first recognized by Richelieu, who in
1631 constructed a harbour with wooden wharves, which soon became a station
of the French navy. Colbert changed the wooden wharves for masonry and
otherwise improved the post, and Vauban's fortifications followed in
1680-1688. During the 18th century the fortifications and the naval
importance of the town continued to develop. In 1694 an English squadron
under John, 3rd Lord Berkeley, was miserably defeated in attempting a
landing; but in 1794, during the revolutionary war, the French fleet, under
Villaret de Joyeuse, was as thoroughly beaten in the same place by the
English admiral Howe.

BREST-LITOVSK (Polish _Brzesc-Litevski_; and in the Chron. _Berestie_ and
_Berestov_), a strongly fortified town of Russia, in the government of
Grodno, 137 m. by rail S. from the city of Grodno, in 52° 5' N. lat. and
23° 39' E. long., at the junction of the navigable river Mukhovets with the
Bug, and at the intersection of railways from Warsaw, Kiev, Moscow and East
Prussia. Pop. (1867) 22,493; (1901) 42,812, of whom more than one-half were
Jews. It contains a Jewish synagogue, which was regarded in the 16th
century as the first in Europe, and is the seat of an Armenian and of a
Greek Catholic bishop; the former has authority over the Armenians
throughout the whole country. The town carries on an extensive trade in
grain, flax, hemp, wood, tar and leather. First mentioned in the beginning
of the 11th century, Brest-Litovsk was in 1241 laid waste by the Mongols
and was not rebuilt till 1275; its suburbs were burned by the Teutonic
Knights in 1379; and in the end of the 15th century the whole town met a
similar fate at the hands of the khan of the Crimea. In the reign of the
Polish king Sigismund III. diets were held there; and in 1594 and 1596 it
was the meeting-place of two remarkable councils of the bishops of western
Russia. In 1657, and again in 1706, the town was captured by the Swedes; in
1794 it was the scene of Suvarov's victory over the Polish general
Sierakowski; in 1795 it was added to the Russian empire. The Brest-Litovsk
or King's canal (50 m. long), utilizing the Mukhovets-Bug rivers, forms a
link in the waterways that connect the Dnieper with the Vistula.

BRETEUIL, LOUIS CHARLES AUGUSTE LE TONNELIER, BARON DE (1730-1807), French
diplomatist, was born at the chateau of Azay-le-Féron (Indre) on the 7th of
March 1730. He was only twenty-eight when he was appointed by Louis XV.
ambassador to the elector of Cologne, and two years later he was sent to St
Petersburg. He arranged to be temporarily absent from his post at the time
of the palace revolution by which Catherine II. was placed on the throne.
In 1769 he was sent to Stockholm, and subsequently represented his
government at Vienna, Naples, and again at Vienna until 1783, when he was
recalled to become minister of the king's household. In this capacity he
introduced considerable reforms in prison administration. A close friend of
Marie Antoinette, he presently came into collision with Calonne, who
demanded his dismissal in 1787. His influence with the king and queen,
especially with the latter, remained unshaken, and on Necker's dismissal on
the 11th of July 1789, Breteuil succeeded him as chief minister. The fall
of the Bastille three days later put an end to the new ministry, and
Breteuil made his way to Switzerland with the first party of _émigrés_. At
Soleure, in November 1790, he received from Louis XVI. exclusive powers to
negotiate with the European courts, and in his efforts to check the
ill-advised diplomacy of the _émigré_ princes, he soon brought himself into
opposition with his old rival Calonne, who held a chief place in their
councils. [v.04 p.0501] After the failure of the flight to Varennes, in the
arrangement of which he had a share, Breteuil received instructions from
Louis XVI., designed to restore amicable relations with the princes. His
distrust of the king's brothers and his defence of Louis XVI.'s prerogative
were to some extent justified, but his intransigeant attitude towards these
princes emphasized the dissensions of the royal family in the eyes of
foreign sovereigns, who looked on the comte de Provence as the natural
representative of his brother and found a pretext for non-interference on
Louis's behalf in the contradictory statements of the negotiators. Breteuil
himself was the object of violent attacks from the party of the princes,
who asserted that he persisted in exercising powers which had been revoked
by Louis XVI. After the execution of Marie Antoinette he retired into
private life near Hamburg, only returning to France in 1802. He died in
Paris on the 2nd of November 1807.

See the memoirs of Bertrand de Molleville (2 vols., Paris, 1816) and of the
marquis de Bouillé (2 vols., Paris, 1884); and E. Daudet, _Coblentz,
1789-1793_ (1889), forming part of his _Hist. de l'émigration._

BRÉTIGNY, a French town (dept. Eure-et-Loir, arrondissement and canton of
Chartres, commune of Sours), which gave its name to a celebrated treaty
concluded there on the 8th of May 1360, between Edward III. of England and
John II., surnamed the Good, of France. The exactions of the English, who
wished to yield as few as possible of the advantages claimed by them in the
treaty of London, made negotiations difficult, and the discussion of terms
begun early in April lasted more than a month. By virtue of this treaty
Edward III. obtained, besides Guienne and Gascony, Poitou, Saintonge and
Aunis, Agenais, Périgord, Limousin, Quercy, Bigorre, the countship of
Gaure, Angoumois, Rouergue, Montreuil-sur-mer, Ponthieu, Calais, Sangatte,
Ham and the countship of Guines. John II. had, moreover, to pay three
millions of gold crowns for his ransom. On his side the king of England
gave up the duchies of Normandy and Touraine, the countships of Anjou and
Maine, and the suzerainty of Brittany and of Flanders. As a guarantee for
the payment of his ransom, John the Good gave as hostages two of his sons,
several princes and nobles, four inhabitants of Paris, and two citizens
from each of the nineteen principal towns of France. This treaty was
ratified and sworn to by the two kings and by their eldest sons on the 24th
of October 1360, at Calais. At the same time were signed the special
conditions relating to each important article of the treaty, and the
renunciatory clauses in which the kings abandoned their rights over the
territory they had yielded to one another.

See Rymer's _Foedera_, vol. iii; Dumont, _Corps diplomatique_, vol. ii.;
Froissart, ed. Luce, vol. vi.; _Les Grandes Chroniques de France_, ed. P.
Paris, vol. vi.; E. Cosneau, _Les Grands Traités de la guerre de cent ans_
(1889).

BRETON, JULES ADOLPHE AIMÉ LOUIS (1827- ), French painter, was born on the
1st of May 1827, at Courrières, Pas de Calais, France. His artistic gifts
being manifest at an early age, he was sent in 1843 to Ghent, to study
under the historical painter de Vigne, and in 1846 to Baron Wappers at
Antwerp. Finally he worked in Paris under Drolling. His first efforts were
in historical subjects: "Saint Piat preaching in Gaul"; then, under the
influence of the revolution of 1848, he represented "Misery and Despair."
But Breton soon discovered that he was not born to be a historical painter,
and he returned to the memories of nature and of the country which were
impressed on him in early youth. In 1853 he exhibited the "Return of the
Harvesters" at the Paris Salon, and the "Little Gleaner" at Brussels.
Thenceforward he was essentially a painter of rustic life, especially in
the province of Artois, which he quitted only three times for short
excursions: in 1864 to Provence, and in 1865 and 1873 to Brittany, whence
he derived some of his happiest studies of religious scenes. His numerous
subjects may be divided generally into four classes: labour, rest, rural
festivals and religious festivals. Among his more important works may be
named "Women Gleaning," and "The Day after St Sebastian's Day" (1855),
which gained him a third-class medal; "Blessing the Fields" (1857), a
second-class medal; "Erecting a Calvary" (1859), now in the Lille gallery;
"The Return of the Gleaners" (1859), now in the Luxembourg; "Evening" and
"Women Weeding" (1861), a first-class medal; "Grandfather's Birthday"
(1862); "The Close of Day" (1865); "Harvest" (1867); "Potato Gatherers"
(1868); "A Pardon, Brittany" (1869); "The Fountain" (1872), medal of
honour; "The Bonfires of St John" (1875); "Women mending Nets" (1876), in
the Douai museum; "A Gleaner" (1877), Luxembourg; "Evening, Finistère"
(1881); "The Song of the Lark" (1884); "The Last Sunbeam" (1885); "The
Shepherd's Star" (1888); "The Call Home" (1889); "The Last Gleanings"
(1895); "Gathering Poppies" (1897); "The Alarm Cry" (1899); "Twilight
Glory" (1900). Breton was elected to the Institut in 1886 on the death of
Baudry. In 1889 he was made commander of the Legion of Honour, and in 1899
foreign member of the Royal Academy of London. He also wrote several books,
among them _Les Champs et la mer_ (1876), _Nos peintres du siècle_ (1900),
"Jeanne," a poem, _Delphine Bernard_ (1902), and _La Peinture_ (1904).

See Jules Breton, _Vie d'un artiste, art et nature_ (autobiographical),
(Paris, 1890); Marius Vachon, _Jules Breton_ (1899).

BRETON, BRITTON OR BRITTAINE, NICHOLAS (1545?-1626), English poet, belonged
to an old family settled at Layer-Breton, Essex. His father, William
Breton, who had made a considerable fortune by trade, died in 1559, and the
widow (née Elizabeth Bacon) married the poet George Gascoigne before her
sons had attained their majority. Nicholas Breton was probably born at the
"capitall mansion house" in Red Cross Street, in the parish of St Giles
without Cripplegate, mentioned in his father's will. There is no official
record of his residence at the university, but the diary of the Rev.
Richard Madox tells us that he was at Antwerp in 1583 and was "once of
Oriel College." He married Ann Sutton in 1593, and had a family. He is
supposed to have died shortly after the publication of his last work,
_Fantastickes_ (1626). Breton found a patron in Mary, countess of Pembroke,
and wrote much in her honour until 1601, when she seems to have withdrawn
her favour. It is probably safe to supplement the meagre record of his life
by accepting as autobiographical some of the letters signed N.B. in _A
Poste with a Packet of Mad Letters_ (1603, enlarged 1637); the 19th letter
of the second part contains a general complaint of many griefs, and
proceeds as follows: "hath another been wounded in the warres, fared hard,
lain in a cold bed many a bitter storme, and beene at many a hard banquet?
all these have I; another imprisoned? so have I; another long been sicke?
so have I; another plagued with an unquiet life? so have I; another
indebted to his hearts griefe, and fame would pay and cannot? so am I."
Breton was a facile writer, popular with his contemporaries, and forgotten
by the next generation. His work consists of religious and pastoral poems,
satires, and a number of miscellaneous prose tracts. His religious poems
are sometimes wearisome by their excess of fluency and sweetness, but they
are evidently the expression of a devout and earnest mind. His praise of
the Virgin and his references to Mary Magdalene have suggested that he was
a Catholic, but his prose writings abundantly prove that he was an ardent
Protestant. Breton had little gift for satire, and his best work is to be
found in his pastoral poetry. His _Passionate Shepheard_ (1604) is full of
sunshine and fresh air, and of unaffected gaiety. The third pastoral in
this book--"Who can live in heart so glad As the merrie country lad"--is
well known; with some other of Breton's daintiest poems, among them the
lullaby, "Come little babe, come silly soule,"[1]--it is incorporated in
A.H. Bullen's _Lyrics from Elizabethan Romances_ (1890). His keen
observation of country life appears also in his prose idyll, _Wits
Trenchmour_, "a conference betwixt a scholler and an angler," and in his
_Fantastickes_, a series of short prose pictures of the months, the
Christian festivals and the hours, which throw much light on the customs of
the times. Most of Breton's books are very rare and have great
bibliographical value. His works, with the exception of some belonging to
private owners, were collected by Dr A.B. Grosart in the [v.04 p.0502]
_Chertsey Worthies Library_ in 1879, with an elaborate introduction quoting
the documents for the poet's history.

Breton's poetical works, the titles of which are here somewhat abbreviated,
include _The Workes of a Young Wit_ (1577); _A Floorish upon Fancie_
(1577); _The Pilgrimage to Paradise_ (1592); _The Countess of Penbrook's
Passion_ (MS.), first printed by J.O. Halliwell Phillipps in 1853;
_Pasquil's Fooles cappe_, entered at Stationers' Hall in 1600; _Pasquil's
Mistresse_ (1600); _Pasquil's Passe and Passeth Not_ (1600); _Melancholike
Humours_ (1600); _Marie Magdalen's Love: a Solemne Passion of the Soules
Love_ (1595), the first part of which, a prose treatise, is probably by
another hand; the second part, a poem in six-lined stanza, is certainly by
Breton; _A Divine Poem_, including "The Ravisht Soul" and "The Blessed
Weeper" (1601); _An Excellent Poem, upon the Longing of a Blessed Heart_
(1601); _The Soules Heavenly Exercise_ (1601); _The Soules Harmony_ (1602);
_Olde Madcappe newe Gaily mawfrey_ (1602); _The Mother's Blessing_ (1602);
_A True Description of Unthankfulnesse_ (1602); _The Passionate Shepheard_
(1604); _The Soules Immortall Crowne_ (1605); _The Honour of Valour_
(1605); _An Invective against Treason; I would and I would not_ (1614);
_Bryton's Bowre of Delights_ (1591), edited by Dr Grosart in 1893, an
unauthorized publication which contained some poems disclaimed by Breton;
_The Arbor of Amorous Devises_ (entered at Stationers' Hall, 1594), only in
part Breton's; and contributions to _England's Helicon_ and other
miscellanies of verse. Of his twenty-two prose tracts may be mentioned
_Wit's Trenchmour_ (1597), _The Wil of Wit_ (1599), _A Poste with a Packet
of Mad Letters_ (1603). _Sir Philip Sidney's Ourania by N.B._ (1606); _Mary
Magdalen's Lamentations_ (1604), and _The Passion of a Discontented Mind_
(1601), are sometimes, but erroneously, ascribed to Breton.

[1] This poem, however, comes from _The Arbor of Amorous Devises_, which
is only in part Breton's work.

BRETÓN DE LOS HERREROS, MANUEL (1796-1873), Spanish dramatist, was born at
Quel (Logroño) on the 19th of December 1796 and was educated at Madrid.
Enlisting on the 24th of May 1812, he served against the French in Valencia
and Catalonia, and retired with the rank of corporal on the 8th of March
1822. He obtained a minor post in the civil service under the liberal
government, and on his discharge determined to earn his living by writing
for the stage. His first piece, _Á la vejez viruelas_, was produced on the
14th of October 1824, and proved the writer to be the legitimate successor
of the younger Moratin. His industry was astonishing: between October 1824
and November 1828, he composed thirty-nine plays, six of them original, the
rest being translations or recasts of classic masterpieces. In 1831 he
published a translation of Tibullus, and acquired by it an unmerited
reputation for scholarship which secured for him an appointment as
sub-librarian at the national library. But the theatre claimed him for its
own, and with the exception of _Elena_ and a few other pieces in the
fashionable romantic vein, his plays were a long series of successes. His
only serious check occurred in 1840; the former liberal had grown
conservative with age, and in _La Ponchada_ he ridiculed the National
Guard. He was dismissed from the national library, and for a short time was
so unpopular that he seriously thought of emigrating to America; but the
storm blew over, and within two years Bretón de los Herreros had regained
his supremacy on the stage. He became secretary to the Spanish Academy,
quarrelled with his fellow-members, and died at Madrid on the 8th of
November 1873. He is the author of some three hundred and sixty original
plays, twenty-three of which are in prose. No Spanish dramatist of the
nineteenth century approaches him in comic power, in festive invention, and
in the humorous presentation of character, while his metrical dexterity is
unique. _Marcela o a cual de los trés?_ (1831), _Muérete; y verás!_ (1837)
and _La Escuela del matrimonio_ (1852) still hold the stage, and are likely
to hold it so long as Spanish is spoken.

See Marqués de Molíns, _Bretón de los Herreros, recuerdos de su vida y de
sus obras_ (Madrid, 1883); _Obras de Bretón de Herreros_ (5 vols., Madrid,
1883); E. Piñeyro, _El Romanticismo en España_ (Paris, 1904).

(J. F.-K.)

BRETSCHNEIDER, KARL GOTTLIEB (1776-1848), German scholar and theologian,
was born at Gersdorf in Saxony. In 1794 he entered the university of
Leipzig, where he studied theology for four years. After some years of
hesitation he resolved to be ordained, and in 1802 he passed with great
distinction the examination for _candidatus theologiae_, and attracted the
regard of F.V. Reinhard, author of the _System der christlichen Moral_
(1788-1815), then court-preacher at Dresden, who became his warm friend and
patron during the remainder of his life. In 1804-1806 Bretschneider was
_Privat-docent_ at the university of Wittenberg, where he lectured on
philosophy and theology. During this time he wrote his work on the
development of dogma, _Systematische Entwickelung aller in der Dogmatik
vorkommenden Begriffe nach den symbolischen Schriften der
evangelisch-lutherischen und reformirten Kirche_ (1805, 4th ed. 1841),
which was followed by others, including an edition of Ecclesiasticus with a
Latin commentary. On the advance of the French army under Napoleon into
Prussia, he determined to leave Wittenberg and abandon his university
career. Through the good offices of Reinhard, he became pastor of
Schneeberg in Saxony (1807). In 1808 he was promoted to the office of
superintendent of the church of Annaberg, in which capacity he had to
decide, in accordance with the canon law of Saxony, many matters belonging
to the department of ecclesiastical law. But the climate did not agree with
him, and his official duties interfered with his theological studies. With
a view to a change he took the degree of doctor of theology in Wittenberg
in August 1812. In 1816 he was appointed general superintendent at Gotha,
where he remained until his death in 1848. This was the great period of his
literary activity.

In 1820 was published his treatise on the gospel of St John, entitled
_Probabilia de Evangelii el Epistolarum Joannis Apostoli indole et
origine_, which attracted much attention. In it he collected with great
fulness and discussed with marked moderation the arguments against
Johannine authorship. This called forth a number of replies. To the
astonishment of every one, Bretschneider announced in the preface to the
second edition of his _Dogmatik_ in 1822, that he had never doubted the
authenticity of the gospel, and had published his _Probabilia_ only to draw
attention to the subject, and to call forth a more complete defence of its
genuineness. Bretschneider remarks in his autobiography that the
publication of this work had the effect of preventing his appointment as
successor to Karl C. Tittmann in Dresden, the minister Detlev von Einsiedel
(1773-1861) denouncing him as the "slanderer of John" (_Johannisschänder_).
His greatest contribution to the science of exegesis was his _Lexicon
Manuale Graeco-Latinum in libros Novi Testamenti_ (1824, 3rd ed. 1840).
This work was valuable for the use which its author made of the Greek of
the Septuagint, of the Old and New Testament Apocrypha, of Josephus, and of
the apostolic fathers, in illustration of the language of the New
Testament. In 1826 he published _Apologie der neuern Theologie des
evangelischen Deutschlands_. Hugh James Rose had published in England
(1825) a volume of sermons on the rationalist movement (_The State of the
Protestant Religion in Germany_), in which he classed Bretschneider with
the rationalists; and Bretschneider contended that he himself was not a
rationalist in the ordinary sense of the term, but a "rational
supernaturalist." Some of his numerous dogmatic writings passed through
several editions. An English translation of his _Manual of the Religion and
History of the Christian Church_ appeared in 1857. His dogmatic position
seems to be intermediate between the extreme school of naturalists, such as
Heinrich Paulus, J.F. Röhr and Julius Wegscheider on the one hand, and D.F.
Strauss and F.C. Baur on the other. Recognizing a supernatural element in
the Bible, he nevertheless allowed to the full the critical exercise of
reason in the interpretation of its dogmas (cp. Otto Pfleiderer,
_Development of Theology_, pp. 89 ff.).

See his autobiography, _Aus meinem Leben: Selbstbiographie von K.G.
Bretschneider_ (Gotha, 1851), of which a translation, with notes, by
Professor George E. Day, appeared in the _Bibliotheca Sacra and American
Biblical Repository_, Nos. 36 and 38 (1852, 1853); Neudecker in _Die
allgemeine Kirchenzeitung_ (1848), No. 38; Wüstemann, _Bretschneideri
Memoria_ (1848); A.G. Farrar, _Critical History of Free Thought_ (Bampton
Lectures, 1862); Herzog-Hauck, _Realencyklopädie_ (ed. 1897).

BRETTEN, a town of Germany, in the grand duchy of Baden, on the Saalbach, 9
m. S.E. of Bruchsal by rail. Pop. (1900) 4781. It has some manufactories of
machinery and japanned goods, and a considerable trade in timber and
livestock. Bretten was the birthplace of Melanchthon (1497), and in
addition to a [v.04 p.0503] statue of him by Drake, a memorial hall,
containing a collection of his writings and busts and pictures of his
famous contemporaries, has been erected.

BRETWALDA, a word used in the _Anglo-Saxon Chronicle_ under the date 827,
and also in a charter of Æthelstan, king of the English. It appears in
several variant forms (_brytenwalda_, _bretenanwealda_, &c.), and means
most probably "lord of the Britons" or "lord of Britain"; for although the
derivation of the word is uncertain, its earlier syllable seems to be
cognate with the words Briton and Britannia. In the _Chronicle_ the title
is given to Ecgbert, king of the English, "the eighth king that was
Bretwalda," and retrospectively to seven kings who ruled over one or other
of the English kingdoms. The seven names are copied from Bede's _Historia
Ecclesiastica_, and it is interesting to note that the last king named,
Oswiu of Northumbria, lived 150 years before Ecgbert. It has been assumed
that these seven kings exercised a certain superiority over a large part of
England, but if such superiority existed it is certain that it was
extremely vague and was unaccompanied by any unity of organization. Another
theory is that Bretwalda refers to a war-leadership, or _imperium_, over
the English south of the Humber, and has nothing to do with Britons or
Britannia. In support of this explanation it is urged that the title is
given in the _Chronicle_ to Ecgbert in the year in which he "conquered the
kingdom of the Mercians and all that was south of the Humber." Less likely
is the theory of Palgrave that the Bretwaldas were the successors of the
pseudo-emperors, Maximus and Carausius, and claimed to share the imperial
dignity of Rome; or that of Kemble, who derives Bretwalda from the British
word _breotan_, to distribute, and translates it "widely ruling." With
regard to Ecgbert the word is doubtless given as a title in imitation of
its earlier use, and the same remark applies to its use in Æthelstan's
charter.

See E.A. Freeman, _History of the Norman Conquest_, vol. i. (Oxford, 1877);
W. Stubbs, _Constitutional History_, vol. i. (Oxford, 1897); J.R. Green,
_The Making of England_, vol. ii. (London, 1897); F. Palgrave, _The Rise
and Progress of the English Commonwealth_ (London, 1832); J. M. Kemble,
_The Saxons in England_ (London, 1876); J. Rhys, _Celtic Britain_ (London,
1884).

BREUGHEL (or BRUEGHEL), PIETER, Flemish painter, was the son of a peasant
residing in the village of Breughel near Breda. After receiving instruction
in painting from Koek, whose daughter he married, he spent some time in
France and Italy, and then went to Antwerp, where he was elected into the
Academy in 1551. He finally settled at Brussels and died there. The
subjects of his pictures are chiefly humorous figures, like those of D.
Teniers; and if he wants the delicate touch and silvery clearness of that
master, he has abundant spirit and comic power. He is said to have died
about the year 1570 at the age of sixty; other accounts give 1590 as the
date of his death.

His son PIETER, the younger (1564-1637), known as "Hell" Breughel, was born
in Brussels and died at Antwerp, where his "Christ bearing the Cross" is in
the museum.

Another son JAN (c. 1569-1642), known as "Velvet" Breughel, was born at
Brussels. He first applied himself to painting flowers and fruits, and
afterwards acquired considerable reputation by his landscapes and
sea-pieces. After residing long at Cologne he travelled into Italy, where
his landscapes, adorned with small figures, were greatly admired. He left a
large number of pictures, chiefly landscapes, which are executed with great
skill. Rubens made use of Breughel's hand in the landscape part of several
of his small pictures--such as his "Vertumnus and Pomona," the "Satyr
viewing the Sleeping Nymph," and the "Terrestrial Paradise."

BREVET (a diminutive of the Fr. _bref_), a short writing, originally an
official writing or letter, with the particular meaning of a papal
indulgence. The use of the word is mainly confined to a commission, or
official document, giving to an officer in the army a permanent, as opposed
to a local and temporary, rank in the service higher than that he holds
substantively in his corps. In the British army "brevet rank" exists only
above the rank of captain, but in the United States army it is possible to
obtain a brevet as first lieutenant. In France the term _breveté_ is
particularly used with respect to the General Staff, to express the
equivalent of the English "passed Staff College" (p.s.c.).

BREVIARY (Lat. _breviarium_, abridgment, epitome), the book which contains
the offices for the canonical hours, _i.e._ the daily service of the Roman
Catholic Church. As compared with the Anglican Book of Common Prayer it is
both more and less comprehensive; more, in that it includes lessons and
hymns for every day in the year; less, because it excludes the Eucharistic
office (contained in the Missal), and the special offices connected with
baptism, marriage, burial, ordination, &c., which are found in the Ritual
or the Pontifical. In the early days of Christian worship, when Jewish
custom was followed, the Bible furnished all that was thought necessary,
containing as it did the books from which the lessons were read and the
psalms that were recited. The first step in the evolution of the Breviary
was the separation of the Psalter into a choir-book. At first the president
of the local church (bishop) or the leader of the choir chose a particular
psalm as he thought appropriate. From about the 4th century certain psalms
began to be grouped together, a process that was furthered by the monastic
practice of daily reciting the 150 psalms. This took so much time that the
monks began to spread it over a week, dividing each day into hours, and
allotting to each hour its portion of the Psalter. St Benedict in the 6th
century drew up such an arrangement, probably, though not certainly, on the
basis of an older Roman division which, though not so skilful, is the one
in general use. Gradually there were added to these psalter choir-books
additions in the form of antiphons, responses, collects or short prayers,
for the use of those not skilful at improvisation and metrical
compositions. Jean Beleth, a 12th-century liturgical author, gives the
following list of books necessary for the right conduct of the canonical
office:--the _Antiphonarium_, the Old and New Testaments, the
_Passionarius_ (_liber_) and the _Legendarius_ (dealing respectively with
martyrs and saints), the _Homiliarius_ (homilies on the Gospels), the
_Sermologus_ (collection of sermons) and the works of the Fathers, besides,
of course, the _Psalterium_ and the _Collectarium_. To overcome the
inconvenience of using such a library the Breviary came into existence and
use. Already in the 8th century Prudentius, bishop of Troyes, had in a
_Breviarium Psalterii_ made an abridgment of the Psalter for the laity,
giving a few psalms for each day, and Alcuin had rendered a similar service
by including a prayer for each day and some other prayers, but no lessons
or homilies. The Breviary rightly so called, however, only dates from the
11th century; the earliest MS. containing the whole canonical office is of
the year 1099 and is in the Mazarin library. Gregory VII. (pope 1073-1085),
too, simplified the liturgy as performed at the Roman court, and gave his
abridgment the name of Breviary, which thus came to denote a work which
from another point of view might be called a Plenary, involving as it did
the collection of several works into one. There are several extant
specimens of 12th-century Breviaries, all Benedictine, but under Innocent
III. (pope 1198-1216) their use was extended, especially by the newly
founded and active Franciscan order. These preaching friars, with the
authorization of Gregory IX., adopted (with some modifications, _e.g._ the
substitution of the "Gallican" for the "Roman" version of the Psalter) the
Breviary hitherto used exclusively by the Roman court, and with it
gradually swept out of Europe all the earlier partial books (Legendaries,
Responsories), &c., and to some extent the local Breviaries, like that of
Sarum. Finally, Nicholas III. (pope 1277-1280) adopted this version both
for the curia and for the basilicas of Rome, and thus made its position
secure. The Benedictines and Dominicans have Breviaries of their own. The
only other types that merit notice are:--(1) the Mozarabic Breviary, once
in use throughout all Spain, but now confined to a single foundation at
Toledo; it is remarkable for the number and length of its hymns, and for
the fact that the majority of its collects are addressed to God the Son;
(2) the Ambrosian, now confined to Milan, where it owes its retention to
the attachment of the clergy and people to their traditionary rites, which
they derive from St Ambrose (see LITURGY).

[v.04 p.0504] Till the council of Trent every bishop had full power to
regulate the Breviary of his own diocese; and this was acted upon almost
everywhere. Each monastic community, also, had one of its own. Pius V.
(pope 1566-1572), however, while sanctioning those which could show at
least 200 years of existence, made the Roman obligatory in all other
places. But the influence of the court of Rome has gradually gone much
beyond this, and has superseded almost all the local "uses." The Roman has
thus become nearly universal, with the allowance only of additional offices
for saints specially venerated in each particular diocese. The Roman
Breviary has undergone several revisions: The most remarkable of these is
that by Francis Quignonez, cardinal of Santa Croce in Gerusalemme (1536),
which, though not accepted by Rome,[1] formed the model for the still more
thorough reform made in 1549 by the Church of England, whose daily morning
and evening services are but a condensation and simplification of the
Breviary offices. Some parts of the prefaces at the beginning of the
English Prayer-Book are free translations of those of Quignonez. The Pian
Breviary was again altered by Sixtus V. in 1588, who introduced the revised
Vulgate text; by Clement VIII. in 1602 (through Baronius and Bellarmine),
especially as concerns the rubrics; and by Urban VIII. (1623-1644), a
purist who unfortunately tampered with the text of the hymns, injuring both
their literary charm and their historic worth.

In the 17th and 18th centuries a movement of revision took place in France,
and succeeded in modifying about half the Breviaries of that country.
Historically, this proceeded from the labours of Jean de Launoy
(1603-1678), "le dénicheur des saints," and Louis Sébastien le Nain de
Tillemont, who had shown the falsity of numerous lives of the saints; while
theologically it was produced by the Port Royal school, which led men to
dwell more on communion with God as contrasted with the invocation of the
saints. This was mainly carried out by the adoption of a rule that all
antiphons and responses should be in the exact words of Scripture, which,
of course, cut out the whole class of appeals to created beings. The
services were at the same time simplified and shortened, and the use of the
whole Psalter every week (which had become a mere theory in the Roman
Breviary, owing to its frequent supersession by saints' day services) was
made a reality. These reformed French Breviaries--_e.g._ the Paris Breviary
of 1680 by Archbishop François de Harlay (1625-1695) and that of 1736 by
Archbishop Charles Gaspard Guillaume de Vintimille (1655-1746)--show a deep
knowledge of Holy Scripture, and much careful adaptation of different
texts; but during the pontificate of Pius IX. a strong Ultramontane
movement arose against them. This was inaugurated by Montalembert, but its
literary advocates were chiefly Dom Gueranger, a learned Benedictine monk,
abbot of Solesmes, and Louis François Veuillot (1813-1883) of the
_Univers_; and it succeeded in suppressing them everywhere, the last
diocese to surrender being Orleans in 1875. The Jansenist and Gallican
influence was also strongly felt in Italy and in Germany, where Breviaries
based on the French models were published at Cologne, Münster, Mainz and
other towns. Meanwhile, under the direction of Benedict XIV. (pope
1740-1758), a special congregation collected many materials for an official
revision, but nothing was published. Subsequent changes have been very few
and minute. In 1902, under Leo XIII., a commission under the presidency of
Monsignor Louis Duchesne was appointed to consider the Breviary, the
Missal, the Pontifical and the Ritual.

The beauty and value of many of the Latin Breviaries were brought to the
notice of English churchmen by one of the numbers of the Oxford _Tracts for
the Times_, since which time they have been much more studied, both for
their own sake and for the light they throw upon the English Prayer-Book.

From a bibliographical point of view some of the early printed Breviaries
are among the rarest of literary curiosities, being merely local. The
copies were not spread far, and were soon worn out by the daily use made of
them. Doubtless many editions have perished without leaving a trace of
their existence, while others are known by unique copies. In Scotland the
only one which has survived the convulsions of the 16th century is that of
Aberdeen, a Scottish form of the Sarum Office,[2] revised by William
Elphinstone (bishop 1483-1514), and printed at Edinburgh by Walter Chapman
and Andrew Myllar in 1509-1510. Four copies have been preserved of it, of
which only one is complete; but it was reprinted in facsimile in 1854 for
the Bannatyne Club by the munificence of the duke of Buccleuch. It is
particularly valuable for the trustworthy notices of the early history of
Scotland which are embedded in the lives of the national saints. Though
enjoined by royal mandate in 1501 for general use within the realm of
Scotland, it was probably never widely adopted. The new Scottish _Proprium_
sanctioned for the Roman Catholic province of St Andrews in 1903 contains
many of the old Aberdeen collects and antiphons.

The Sarum or Salisbury Breviary itself was very widely used. The first
edition was printed at Venice in 1483 by Raynald de Novimagio in folio; the
latest at Paris, 1556, 1557. While modern Breviaries are nearly always
printed in four volumes, one for each season of the year, the editions of
the Sarum never exceeded two parts.

_Contents of the Roman Breviary_.--At the beginning stands the usual
introductory matter, such as the tables for determining the date of Easter,
the calendar, and the general rubrics. The Breviary itself is divided into
four seasonal parts--winter, spring, summer, autumn--and comprises under
each part (1) the Psalter; (2) _Proprium de Tempore_ (the special office of
the season); (3) _Proprium Sanctorum_ (special offices of saints); (4)
_Commune Sanctorum_ (general offices for saints); (5) Extra Services. These
parts are often published separately.

1. _The Psalter_.--This is the very backbone of the Breviary, the
groundwork of the Catholic prayer-book; out of it have grown the antiphons,
responsories and versicles. In the Breviary the psalms are arranged
according to a disposition dating from the 8th century, as follows. Psalms
i.-cviii., with some omissions, are recited at Matins, twelve each day from
Monday to Saturday, and eighteen on Sunday. The omissions are said at
Lauds, Prime and Compline. Psalms cix.-cxlvii. (except cxvii., cxviii. and
cxlii.) are said at Vespers, five each day. Psalms cxlviii.-cl. are always
used at Lauds, and give that hour its name. The text of this Psalter is
that commonly known as the Gallican. The name is misleading, for it is
simply the second revision (A.D. 392) made by Jerome of the old _Itala_
version originally used in Rome. Jerome's first revision of the _Itala_
(A.D. 383), known as the Roman, is still used at St Peter's in Rome, but
the "Gallican," thanks especially to St Gregory of Tours, who introduced it
into Gaul in the 6th century, has ousted it everywhere else. The
Antiphonary of Bangor proves that Ireland accepted the Gallican version in
the 7th century, and the English Church did so in the 10th.

2. The _Proprium de Tempore_ contains the office of the seasons of the
Christian year (Advent to Trinity), a conception that only gradually grew
up. There is here given the whole service for every Sunday and week-day,
the proper antiphons, responsories, hymns, and especially the course of
daily Scripture-reading, averaging about twenty verses a day, and (roughly)
arranged thus: for Advent, Isaiah; Epiphany to Septuagesima, Pauline
Epistles; Lent, patristic homilies (Genesis on Sundays); Passion-tide,
Jeremiah; Easter to Whitsun, Acts, Catholic epistles and Apocalypse;
Whitsun to August, Samuel and Kings; August to Advent, Wisdom books,
Maccabees, Prophets. The extracts are often scrappy and torn out of their
context.

3. The _Proprium Sanctorum_ contains the lessons, psalms and liturgical
formularies for saints' festivals, and depends on the days of the secular
month. Most of the material here is hagiological biography, occasionally
revised as by Leo XIII. in view of archaeological and other discoveries,
but still largely uncritical. Covering a great stretch of time and space,
they do for the worshipper in the field of church history what the
Scripture readings do in that of biblical history. As something like 90% of
the days in the year have, during the course of centuries, been allotted to
some saint or other, it is easy to see how this section of the Breviary has
encroached upon the _Proprium de Tempore_, and this is the chief problem
that confronts any who are concerned for a revision of the Breviary.

4. The _Commune Sanctorum_ comprises psalms, antiphons, lessons, &c., for
feasts of various groups or classes (twelve in all); _e.g._ apostles,
martyrs, confessors, virgins, and the Blessed Virgin Mary. These offices
are of very ancient date, and many of them were probably [v.04 p.0505] in
origin proper to individual saints. They contain passages of great literary
beauty. The lessons read at the third nocturn are patristic homilies on the
Gospels, and together form a rough summary of theological instruction.

5. _Extra Services_.--Here are found the Little Office of the Blessed
Virgin Mary, the Office of the Dead (obligatory on All Souls' Day), and
offices peculiar to each diocese.

It has already been indicated, by reference to Matins, Lauds, &c., that not
only each day, but each part of the day, has its own office, the day being
divided into liturgical "hours." A detailed account of these will be found
in the article HOURS, CANONICAL. Each of the hours of the office is
composed of the same elements, and something must be said now of the nature
of these constituent parts, of which mention has here and there been
already made. They are: psalms (including canticles), antiphons,
responsories, hymns, lessons, little chapters, versicles and collects.

The _psalms_ have already been dealt with, but it may be noted again how
the multiplication of saints' festivals, with practically the same special
psalms, tends in practice to constant repetition of about one-third of the
Psalter, and correspondingly rare recital of the remaining two-thirds,
whereas the _Proprium de Tempore_, could it be adhered to, would provide
equal opportunities for every psalm. As in the Greek usage and in the
Benedictine, certain canticles like the Song of Moses (Exodus xv.), the
Song of Hannah (1 Sam. ii.), the prayer of Habakkuk (iii.), the prayer of
Hezekiah (Isaiah xxxviii.) and other similar Old Testament passages, and,
from the New Testament, the Magnificat, the Benedictus and the Nunc
dimittis, are admitted as psalms.

The _antiphons_ are short liturgical forms, sometimes of biblical,
sometimes of patristic origin, used to introduce a psalm. The term
originally signified a chant by alternate choirs, but has quite lost this
meaning in the Breviary.

The _responsories_ are similar in form to the antiphons, but come at the
end of the psalm, being originally the reply of the choir or congregation
to the precentor who recited the psalm.

The _hymns_ are short poems going back in part to the days of Prudentius,
Synesius, Gregory of Nazianzus and Ambrose (4th and 5th centuries), but
mainly the work of medieval authors. Together they make a fine collection,
and it is a pity that Urban VIII. in his mistaken humanistic zeal tried to
improve them.

The _lessons_, as has been seen, are drawn variously from the Bible, the
Acts of the Saints and the Fathers of the Church. In the primitive church,
books afterwards excluded from the canon were often read, _e.g._ the
letters of Clement of Rome and the _Shepherd of Hermas_. In later days the
churches of Africa, having rich memorials of martyrdom, used them to
supplement the reading of Scripture. Monastic influence accounts for the
practice of adding to the reading of a biblical passage some patristic
commentary or exposition. Books of homilies were compiled from the writings
of SS. Augustine, Hilary, Athanasius, Isidore, Gregory the Great and
others, and formed part of the library of which the Breviary was the
ultimate compendium. In the lessons, as in the psalms, the order for
special days breaks in upon the normal order of ferial offices and
dislocates the scheme for consecutive reading. The lessons are read at
Matins (which is subdivided into three nocturns).

The _little chapters_ are very short lessons read at the other "hours."

The _versicles_ are short responsories used after the little chapters.

The _collects_ come at the close of the office and are short prayers
summing up the supplications of the congregation. They arise out of a
primitive practice on the part of the bishop (local president), examples of
which are found in the _Didach[=e]_ (Teaching of the Apostles) and in the
letters of Clement of Rome and Cyprian. With the crystallization of church
order improvisation in prayer largely gave place to set forms, and
collections of prayers were made which later developed into Sacramentaries
and Orationals. The collects of the Breviary are largely drawn from the
Gelasian and other Sacramentaries, and they are used to sum up the dominant
idea of the festival in connexion with which they happen to be used.

The difficulty of harmonizing the _Proprium de Tempore_ and the _Proprium
Sanctorum_, to which reference has been made, is only partly met in the
thirty-seven chapters of general rubrics. Additional help is given by a
kind of Catholic Churchman's Almanack, called the _Ordo Recitandi Divini
Officii_, published in different countries and dioceses, and giving, under
every day, minute directions for proper reading.

Every clerk in orders and every member of a religious order must publicly
join in or privately read aloud (_i.e._ using the lips as well as the
eyes--it takes about two hours in this way) the whole of the Breviary
services allotted for each day. In large churches the services are usually
grouped; _e.g._ Matins and Lauds (about 7.30 A.M.); Prime, Terce (High
Mass), Sext, and None (about 10 A.M.); Vespers and Compline (4 P.M.); and
from four to eight hours (depending on the amount of music and the number
of high masses) are thus spent in choir. Laymen do not use the Breviary as
a manual of devotion to any great extent.

The Roman Breviary has been translated into English (by the marquess of
Bute in 1879; new ed. with a trans, of the Martyrology, 1908), French and
German. The English version is noteworthy for its inclusion of the skilful
renderings of the ancient hymns by J.H. Newman, J.M. Neale and others.

AUTHORITIES.--F. Cabrol, _Introduction aux études liturgiques_; Probst,
_Kirchenlex_. ii., _s.v._ "Brevier"; Bäumer, _Geschichte des Breviers_
(Freiburg, 1895); P. Batiffol, _L'Histoire du bréviaire romain_ (Paris,
1893; Eng. tr.); Baudot, _Le Bréviaire romain_ (1907). A complete
bibliography is appended to the article by F. Cabrol in the _Catholic
Encyclopaedia_, vol. ii. (1908).

[1] It was approved by Clement VII. and Paul III., and permitted as a
substitute for the unrevised Breviary, until Pius V. in 1568 excluded it as
too short and too modern, and issued a reformed edition (_Breviarium
Pianum_, Pian Breviary) of the old Breviary.

[2] The Sarum Rite was much favoured in Scotland as a kind of protest
against the jurisdiction claimed by the church of York.

BREVIARY OF ALARIC (_Breviarium Alaricanum_), a collection of Roman law,
compiled by order of Alaric II., king of the Visigoths, with the advice of
his bishops and nobles, in the twenty-second year of his reign (A.D. 506).
It comprises sixteen books of the Theodosian code; the Novels of Theodosius
II., Valentinian III., Marcian, Majorianus and Severus; the Institutes of
Gaius; five books of the _Sententiae Receptae_ of Julius Paulus; thirteen
titles of the Gregorian code; two titles of the Hermogenian code; and a
fragment of the first book of the _Responsa Papiniani_. It is termed a code
(codex), in the certificate of Anianus, the king's referendary, but unlike
the code of Justinian, from which the writings of jurists were excluded, it
comprises both imperial constitutions (_leges_) and juridical treatises
(_jura_). From the circumstance that the Breviarium has prefixed to it a
royal rescript (_commonitorium_) directing that copies of it, certified
under the hand of Anianus, should be received exclusively as law throughout
the kingdom of the Visigoths, the compilation of the code has been
attributed to Anianus by many writers, and it is frequently designated the
Breviary of Anianus (Breviarium Aniani). The code, however, appears to have
been known amongst the Visigoths by the title of "Lex Romana," or "Lex
Theodosii," and it was not until the 16th century that the title of
"Breviarium" was introduced to distinguish it from a recast of the code,
which was introduced into northern Italy in the 9th century for the use of
the Romans in Lombardy. This recast of the Visigothic code has been
preserved in a MS. known as the Codex Utinensis, which was formerly kept in
the archives of the cathedral of Udine, but is now lost; and it was
published in the 18th century for the first time by P. Canciani in his
collection of ancient laws entitled _Barbarorum Leges Antiquae_. Another
MS. of this Lombard recast of the Visigothic code was discovered by Hänel
in the library of St Gall. The chief value of the Visigothic code consists
in the fact that it is the only collection of Roman Law in which the five
first books of the Theodosian code and five books of the _Sententiae
Receptae_ of Julius Paulus have been preserved, and until the discovery of
a MS. in the chapter library in Verona, which contained the greater part of
the Institutes of Gaius, it was the only work in which any portion of the
institutional writings of that great jurist had come down to us.

The most complete edition of the Breviarium will be found in the collection
of Roman law published under the title of _Jus Civile Ante-Justinianum_
(Berlin, 1815). See also G. Hänel's _Lex Romana Visigothorum_ (Berlin,
1847-1849).

BREWER, JOHN SHERREN (1810-1879), English historian, was born in Norwich in
1810, the son of a Baptist schoolmaster. He was educated at Queen's
College, Oxford, was ordained in the Church of England in 1837, and became
chaplain to a central London workhouse. In 1839 he was appointed lecturer
in classical literature at King's College, London, and in 1855 he became
professor of English language and literature and lecturer in modern
history, succeeding F.D. Maurice. Meanwhile from 1854 onwards he was also
engaged in journalistic work on the _Morning Herald_, _Morning Post_ and
_Standard_. In 1856 he was commissioned by the master of the rolls to
prepare a calendar of the state papers of Henry VIII., a work demanding a
vast amount of research. He was also made reader at the Rolls, and
subsequently preacher. In 1877 Disraeli secured for him the crown living of
Toppesfield, Essex. There he had time to continue his task of preparing his
_Letters and Papers of the Reign of King Henry VIII_., the Introductions to
which (published separately, under the title _The Reign of Henry VIII_., in
1884) form a scholarly and authoritative history of Henry VIII.'s reign.
New editions of several standard historical works were also produced under
Brewer's direction. He died at Toppesfield in February 1879.

[v.04 p.0506] BREWING, in the modern acceptation of the term, a series of
operations the object of which is to prepare an alcoholic beverage of a
certain kind--to wit, beer--mainly from cereals (chiefly malted barley),
hops and water. Although the art of preparing beer (_q.v._) or ale is a
very ancient one, there is very little information in the literature of the
subject as to the apparatus and methods employed in early times. It seems
fairly certain, however, that up to the 18th century these were of the most
primitive kind. With regard to _materials_, we know that prior to the
general introduction of the hop (see ALE) as a preservative and astringent,
a number of other bitter and aromatic plants had been employed with this
end in view. Thus J.L. Baker (_The Brewing Industry_) points out that the
Cimbri used the _Tamarix germanica_, the Scandinavians the fruit of the
sweet gale (_Myrica gale_), the Cauchi the fruit and the twigs of the
chaste tree (_Vitex agrius castus_), and the Icelanders the yarrow
(_Achillea millefolium_).

The preparation of beer on anything approaching to a manufacturing scale
appears, until about the 12th or 13th century, to have been carried on in
England chiefly in the monasteries; but as the brewers of London combined
to form an association in the reign of Henry IV., and were granted a
charter in 1445, it is evident that brewing as a special trade or industry
must have developed with some rapidity. After the Reformation the ranks of
the trade brewers were swelled by numbers of monks from the expropriated
monasteries. Until the 18th century the professional brewers, or brewers
for sale, as they are now called, brewed chiefly for the masses, the
wealthier classes preparing their own beer, but it then became gradually
apparent to the latter (owing no doubt to improved methods of brewing, and
for others reasons) that it was more economical and less troublesome to
have their beer brewed for them at a regular brewery. The usual charge was
30s. per barrel for bitter ale, and 8s. or so for small beer. This tendency
to centralize brewing operations became more and more marked with each
succeeding decade. Thus during 1895-1905 the number of private brewers
declined from 17,041 to 9930. Of the private brewers still existing, about
four-fifths were in the class exempted from beer duty, _i.e._ farmers
occupying houses not exceeding £10 annual value who brew for their
labourers, and other persons occupying houses not exceeding £15 annual
value. The private houses subject to both beer and licence duty produced
less than 20,000 barrels annually. There are no official figures as to the
number of "cottage brewers," that is, occupiers of dwellings not exceeding
£8 annual value; but taking everything into consideration it is probable
that more than 99% of the beer produced in the United Kingdom is brewed by
public brewers (brewers for sale). The disappearance of the smaller public
brewers or their absorption by the larger concerns has gone hand-in-hand
with the gradual extinction of the private brewer. In the year 1894-1895
8863 licences were issued to brewers for sale, and by 1904-1905 this number
had been reduced to 5164. There are numerous reasons for these changes in
the constitution of the brewing industry, chief among them being (a) the
increasing difficulty, owing partly to licensing legislation and its
administration, and partly to the competition of the great breweries, of
obtaining an adequate outlet for retail sale in the shape of licensed
houses; and (b) the fact that brewing has continuously become a more
scientific and specialized industry, requiring costly and complicated plant
and expert manipulation. It is only by employing the most up-to-date
machinery and expert knowledge that the modern brewer can hope to produce
good beer in the short time which competition and high taxation, &c., have
forced upon him. Under these conditions the small brewer tends to
extinction, and the public are ultimately the gainers. The relatively
non-alcoholic, lightly hopped and bright modern beers, which the small
brewer has not the means of producing, are a great advance on the muddy,
highly hopped and alcoholized beverages to which our ancestors were
accustomed.

The brewing trade has reached vast proportions in the United Kingdom. The
maximum production was 37,090,986 barrels in 1900, and while there has been
a steady decline since that year, the figures for 1905-1906--34,109,263
barrels--were in excess of those for any year preceding 1897. It is
interesting in this connexion to note that the writer of the article on
Brewing in the 9th edition of the _Encyclopaedia Britannica_ was of the
opinion that the brewing industry--which was then (1875) producing,
roughly, 25,000,000 barrels--had attained its maximum development. In the
year ending 30th September 1905 the beer duty received by the exchequer
amounted to £13,156,053. The number of brewers for sale was 5180. Of these
one firm, namely, Messrs Guinness, owning the largest brewery in the world,
brewed upwards of two million barrels, paying a sum of, roughly, one
million sterling to the revenue. Three other firms brewed close on a
million barrels or upwards. The quantity of malt used was 51,818,697
bushels; of unmalted corn, 125,671 bushels; of rice, flaked maize and
similar materials, 1,348,558 cwt.; of sugar, 2,746,615 cwt.; of hops,
62,360,817 lb; and of hop substitutes, 49,202 lb. The average specific
gravity of the beer produced in 1905-1906 was 1053.24. The quantity of beer
exported was 520,826; of beer imported, 57,194 barrels. It is curious to
note that the figures for exports and imports had remained almost
stationary for the last thirty years. By far the greater part of the beer
brewed is consumed in England. Thus of the total quantity retained for
consumption in 1905-1906, 28,590,563 barrels were consumed in England,
1,648,463 in Scotland, and 3,265,084 in Ireland. In 1871 it was calculated
by Professor Leone Levi that the capital invested in the liquor trade in
the United Kingdom was £117,000,000. In 1908 this figure might be safely
doubled. A writer in the _Brewers' Almanack_ for 1906 placed the capital
invested in limited liability breweries alone at £185,000,000. If we allow
for over-capitalization, it seems fairly safe to say that, prior to the
introduction of the Licensing Bill of 1908, the market value of the
breweries in the United Kingdom, together with their licensed property, was
in the neighbourhood of £120,000,000, to which might be added another
£20,000,000 for the value of licences not included in the above
calculation; the total capital actually sunk in the whole liquor trade
(including the wine and spirit industries and trades) being probably not
far short of £250,000,000, and the number of persons directly engaged in or
dependent on the liquor trade being under-estimated at 2,000,000. (For
comparative production and consumption see BEER.)

_Taxation and Regulations_.--The development of the brewing industry in
England is intimately interwoven with the history of its taxation, and the
regulations which have from time to time been formed for the safeguarding
of the revenue. The first duty on beer in the United Kingdom was imposed in
the reign of Charles II. (1660), namely 2s. 6d. per barrel on strong and
6d. per barrel on weak beer. This was gradually increased, amounting to 4s.
9d. on strong and 1s. 3d. on weak beer in the last decade of the 17th
century, and to 8s. to 10s. in the year 1800, at which rate it continued
until the repeal of the beer duty in 1830. A duty on malt was first imposed
in the reign of William III. (1697), and from that date until 1830 both
beer duty and malt tax were charged. The rate at first was under 7d. per
bushel, but this was increased up to 2s. 7d. prior to the first repeal of
the beer duty (1830), and to 4s. 6d. after the repeal. In 1829 the joint
beer and malt taxes amounted to no less than 13s. 8d. per barrel, or 4½d.
per gallon, as against 2½d. at the present day. From 1856 until the
abolition of the malt tax, the latter remained constant at a fraction under
2s. 8½d. A _hop duty_ varying from 1d. to 2½d. per pound was in existence
between 1711 and 1862. One of the main reasons for the abolition of the hop
duty was the fact that, owing to the uncertainty of the crop, the amount
paid to the revenue was subject to wide fluctuations. Thus in 1855 the
revenue from this source amounted to £728,183, in 1861 to only £149,700.

It was not until 1847 that the use of sugar in brewing was permitted, and
in 1850 the first sugar tax, amounting to 1s. 4d. per cwt., was imposed. It
varied from this figure up to 6s. 6d. in 1854, and in 1874, when the
general duty on sugar was repealed, it was raised to 11s. 6d., at which
rate it remained until 1880, when it was repealed simultaneously with the
malt duty. In 1901 a general sugar tax of 4s. 2d. and under (according to
the percentage of actual sugar contained) was imposed, but no drawback was
allowed to brewers using sugar, and therefore--and this obtains at the
present day--sugar used in brewing pays the general tax and also the beer
duty.

By the Free Mash-Tun Act of 1880, the duty was taken off the malt and
placed on the beer, or, more properly speaking, on the wort; maltsters' and
brewers' licences were repealed, and in lieu thereof an annual licence duty
of £1 payable by every brewer for sale was [v.04 p.0507] imposed. The chief
feature of this act was that, on and after the 1st of October 1880, a beer
duty was imposed in lieu of the old malt tax, at the rate of 6s. 3d. per
barrel of 36 gallons, at a specific gravity of 1.057, and the regulations
for charging the duty were so framed as to leave the brewer practically
unrestricted as to the description of malt or corn and sugar, or other
description of saccharine substitutes (other than deleterious articles or
drugs), which he might use in the manufacture or colouring of beer. This
freedom in the choice of materials has continued down to the present time,
except that the use of "saccharin" (a product derived from coal-tar) was
prohibited in 1888, the reason being that this substance gives an apparent
palate-fulness to beer equal to roughly 4° in excess of its real gravity,
the revenue suffering thereby. In 1889 the duty on beer was increased by a
reduction in the standard of gravity from 1.057 to 1.055, and in 1894 a
further 6d. per barrel was added. The duty thus became 6s. 9d. per barrel,
at a gravity of 1.055, which was further increased to 7s. 9d. per barrel by
the war budget of 1900, at which figure it stood in 1909. (See also LIQUOR
LAWS.)

Prior to 1896, rice, flaked maize (see below), and other similar
preparations had been classed as malt or corn in reference to their
wort-producing powers, but after that date they were deemed sugar[1] in
that regard. By the new act (1880) 42 lb weight of corn, or 28 lb weight of
sugar, were to be deemed the equivalent of a bushel of malt, and a brewer
was expected by one of the modes of charge to have brewed at least a barrel
(36 gallons) of worts (less 4% allowed for wastage) at the standard gravity
for every two bushels of malt (or its equivalents) used by him in brewing;
but where, owing to lack of skill or inferior machinery, a brewer cannot
obtain the standard quantity of wort from the standard equivalent of
material, the charge is made not on the wort, but directly on the material.
By the new act, licences at the annual duty of £1 on brewers for sale, and
of 6s. (subsequently modified by 44 Vict. c. 12, and 48 and 49 Vict. c. 5,
&c., to 4s.) or 9s., as the case might be, on any other brewers, were
required. The regulations dealing with the mashing operations are very
stringent. Twenty-four hours at least before mashing the brewer must enter
in his brewing book (provided by the Inland Revenue) the day and hour for
commencing to mash malt, corn, &c., or to dissolve sugar; and the date of
making such entry; and also, two hours at least before the notice hour for
mashing, the quantity of malt, corn, &c., and sugar to be used, and the day
and hour when all the worts will be drawn off the grains in the mash-tun.
The worts of each brewing must be collected within twelve hours of the
commencement of the collection, and the brewer must within a given time
enter in his book the quantity and gravity of the worts before
fermentation, the number and name of the vessel, and the date of the entry.
The worts must remain in the same vessel undisturbed for twelve hours after
being collected, unless previously taken account of by the officer. There
are other regulations, _e.g._ those prohibiting the mixing of worts of
different brewings unless account has been taken of each separately, the
alteration of the size or shape of any gauged vessel without notice, and so
on.

_Taxation of Beer in Foreign Countries_.--The following table shows the
nature of the tax and the amount of the same calculated to English barrels.

Country. Nature of Tax. Amount per English
Barrel (round
numbers)
United States Beer tax 5s. 9d.
Germany --
---- N. German Customs Malt tax 1s. 6d
Union
---- Bavaria Malt tax 3s. 5d. to 4s. 8d.,
according to
quantity produced
Belgium Malt tax 2s. 9d.
France On Wort 4s. 1d.
Holland On cubic About 1s. 9d. to 3s.
contents of 3d., according to
Mash-Tun or on quality
Malt
Austro-Hungarian Empire On Wort 6s. 8d.
Russia Malt tax 5s. to 6s. 8d.

MATERIALS USED IN BREWING.--These are water, malt (_q.v._), hops (_q.v._),
various substitutes for the two latter, and preservatives.

_Water_.--A satisfactory supply of water--which, it may here be mentioned,
is always called _liquor_ in the brewery--is a matter of great importance
to the brewer. Certain waters, for instance, those contaminated to any
extent with organic matter, cannot be used at all in brewing, as they give
rise to unsatisfactory fermentation, cloudiness and abnormal flavour.
Others again, although suited to the production of one type of beer, are
quite unfit for the brewing of another. For black beers a soft water is a
desideratum, for ales of the Burton type a hard water is a necessity. For
the brewing of mild ales, again, a water containing a certain proportion of
chlorides is required. The presence or absence of certain mineral
substances as such in the finished beer is not, apparently, a matter of any
moment as regards flavour or appearance, but the importance of the rôle
played by these substances in the brewing process is due to the influence
which they exert on the solvent action of the water on the various
constituents of the malt, and possibly of the hops. The excellent quality
of the Burton ales was long ago surmised to be due mainly to the well water
obtainable in that town. On analysing Burton water it was found to contain
a considerable quantity of calcium sulphate--gypsum--and of other calcium
and magnesium salts, and it is now a well-known fact that good bitter ales
cannot be brewed except with waters containing these substances in
sufficient quantities. Similarly, good mild ale waters should contain a
certain quantity of sodium chloride, and waters for stout very little
mineral matter, excepting perhaps the carbonates of the alkaline earths,
which are precipitated on boiling.

The following analyses (from W.J. Sykes, _The Principles and Practice of
Brewing_) are fairly illustrative of typical brewing waters.

_Burton Water_ (Pale Ale)
Grains per Gallon
Sodium Chloride 3.90
Potassium Sulphate 1.59
Sodium Nitrate 1.97
Calcium Sulphate 77.87
Calcium Carbonate 7.62
Magnesium Carbonate 21.31
Silica and Alumina 0.98
_Dublin Water_ (Stout).
Sodium Chloride 1.83
Calcium Sulphate 4.45
Calcium Carbonate 14.21
Magnesium Carbonate 0.90
Iron Oxide and 0.24
Alumina
Silica 0.26
_Mild Ale Water_.
Sodium Chloride 35.14
Calcium Chloride 3.88
Calcium Sulphate 6.23
Calcium Carbonate 4.01
Iron Oxide and 0.24
Alumina
Silica 0.22

Our knowledge of the essential chemical constituents of brewing waters
enables brewers in many cases to treat an unsatisfactory supply
artificially in such a manner as to modify its character in a favourable
sense. Thus, if a soft water only is to hand, and it is desired to brew a
bitter ale, all that is necessary is to add a sufficiency of gypsum,
magnesium sulphate and calcium chloride. If it is desired to convert a soft
water lacking in chlorides into a satisfactory mild ale liquor, the
addition of 30-40 grains of sodium chloride will be necessary. On the other
hand, to convert a hard water into a soft supply is scarcely feasible for
brewing purposes. To the substances used for treating brewing liquors
already mentioned we may add kainite, a naturally deposited composite salt
containing potassium and magnesium sulphates and magnesium chloride.

_Malt Substitutes._--Prior to the repeal of the Malt Acts, the only
substitute for malt allowed in the United Kingdom was sugar. The quantity
of the latter employed was 295,865 cwt. in 1870, 1,136,434 cwt. in 1880,
and 2,746,615 cwt. in 1905; that is to say, that the quantity used had been
practically trebled during the last twenty-five years, although the
quantity of malt employed had not materially increased. At the same time
other substitutes, such as unmalted corn and preparations of rice and
maize, had come into favour, the quantity of these substances used being in
1905 125,671 bushels of unmalted corn and 1,348,558 cwt. of rice, maize,
&c.

The following statistics with regard to the use of malt substitutes in the
United Kingdom are not without interest.

[v.04 p.0508]

Year. Quantities of Quantities of Percentage
Malt and Corn Sugar, Rice, of
used in Maize, &c. used Substitutes
Brewing. in Brewing. to Total
Material.
Bushels. Bushels.
1878 59,388,905 3,825,148 6.05
1883 [2]51,331,451 [3]4,503,680 8.06
1890 [2]55,359,964 [3]7,904,708 12.48
1895 53,731,177 10,754,510 16.66
1905 51,942,368 15,706,413 23.22

The causes which have led to the largely increased use of substitutes in
the United Kingdom are of a somewhat complex nature. In the first place, it
was not until the malt tax was repealed that the brewer was able to avail
himself of the surplus diastatic energy present in malt, for the purpose of
transforming starch (other than that in malted grain) into sugar. The
diastatic enzyme or ferment (see below, under _Mashing_) of malted barley
is present in that material in great excess, and a part of this surplus
energy may be usefully employed in converting the starch of unmalted grain
into sugar. The brewer has found also that brewing operations are
simplified and accelerated by the use of a certain proportion of
substitutes, and that he is thereby enabled appreciably to increase his
turn-over, _i.e._ he can make more beer in a given time from the same
plant. Certain classes of substitutes, too, are somewhat cheaper than malt,
and in view of the keenness of modern competition it is not to be wondered
at that the brewer should resort to every legitimate means at his disposal
to keep down costs. It has been contended, and apparently with much reason,
that if the use of substitutes were prohibited this would not lead to an
increased use of domestic barley, inasmuch as the supply of home barley
suitable for malting purposes is of a limited nature. A return to the
policy of "malt and hops only" would therefore lead to an increased use of
foreign barley, and to a diminution in the demand for home barley, inasmuch
as sugar and prepared cereals, containing as they do less nitrogen, &c.
than even the well-cured, sun-dried foreign barleys, are better diluents
than the latter. At the same time, it is an undoubted fact that an
excessive use of substitutes leads to the production of beer of poor
quality. The better class of brewer rarely uses more than 15-20%, knowing
that beyond that point the loss of flavour and quality will in the long run
become a more serious item than any increased profits which he might
temporarily gain.

With regard to the nature of the substitutes or adjuncts for barley malt
more generally employed, raw grain (unmalted barley, wheat, rice, maize,
&c.) is not used extensively in Great Britain, but in America brewers
employ as much as 50%, and even more, of maize, rice or similar materials.
The maize and rice preparations mostly used in England are practically
starch pure and simple, substantially the whole of the oil, water, and
other subsidiary constituents of the grain being removed. The germ of maize
contains a considerable proportion of an oil of somewhat unpleasant
flavour, which has to be eliminated before the material is fit for use in
the mash-tun. After degerming, the maize is unhusked, wetted, submitted to
a temperature sufficient to rupture the starch cells, dried, and finally
rolled out in a flaky condition. Rice is similarly treated.

The _sugars_ used are chiefly cane sugar, glucose and invert sugar--the
latter commonly known as "saccharum." Cane sugar is mostly used for the
preparation of heavy mild ales and stouts, as it gives a peculiarly sweet
and full flavour to the beer, to which, no doubt, the popularity of this
class of beverage is largely due. _Invert sugar_ is prepared by the action
either of acid or of yeast on cane sugar. The chemical equation
representing the conversion (or inversion) of cane sugar is:--

C12H22O11 + H2O = C6H12O6 + C6H12O6.
cane sugar water glucose fructose
----invert sugar----

Invert sugar is so called because the mixture of glucose and fructose which
forms the "invert" is laevo-rotatory, whereas cane sugar is dextro-rotatory
to the plane of polarized light. The preparation of invert sugar by the
acid process consists in treating the cane sugar in solution with a little
mineral acid, removing the excess of the latter by means of chalk, and
concentrating to a thick syrup. The yeast process (Tompson's), which makes
use of the inverting power of one of the enzymes (invertase) contained in
ordinary yeast, is interesting. The cane sugar solution is pitched with
yeast at about 55° C., and at this comparatively high temperature the
inversion proceeds rapidly, and fermentation is practically impossible.
When this operation is completed, the whole liquid (including the yeast) is
run into the boiling contents of the copper. This method is more suited to
the preparation of invert in the brewery itself than the acid process,
which is almost exclusively used in special sugar works. Glucose, which is
one of the constituents of invert sugar, is largely used by itself in
brewing. It is, however, never prepared from invert sugar for this purpose,
but directly from starch by means of acid. By the action of dilute boiling
acid on starch the latter is rapidly converted first into a mixture of
dextrine and maltose and then into glucose. The proportions of glucose,
dextrine and maltose present in a commercial glucose depend very much on
the duration of the boiling, the strength of the acid, and the extent of
the pressure at which the starch is converted. In England the materials
from which glucose is manufactured are generally sago, rice and purified
maize. In Germany potatoes form the most common raw material, and in
America purified Indian corn is ordinarily employed.

_Hop substitutes_, as a rule, are very little used. They mostly consist of
quassia, gentian and camomile, and these substitutes are quite harmless
_per se_, but impart an unpleasantly rough and bitter taste to the beer.

_Preservatives_.--These are generally, in fact almost universally, employed
nowadays for draught ales; to a smaller extent for stock ales. The light
beers in vogue to-day are less alcoholic, more lightly hopped, and more
quickly brewed than the beers of the last generation, and in this respect
are somewhat less stable and more likely to deteriorate than the latter
were. The preservative in part replaces the alcohol and the hop extract,
and shortens the brewing time. The preservatives mostly used are the
bisulphites of lime and potash, and these, when employed in small
quantities, are generally held to be harmless.

BREWING OPERATIONS.--The general scheme of operations in an English brewery
will be readily understood if reference be made to fig. 1, which represents
an 8-quarter brewery on the _gravitation system_, the principle of which is
that all materials to be employed are pumped or hoisted to the highest
point required, to start with, and that subsequently no further pumping or
hoisting is required, the materials (in the shape of water, malt, wort or
hops, &c.) being conveyed from one point to another by the force of
gravity.

The malt, which is hoisted to the top floor, after cleaning and grading is
conveyed to the _Malt Mill_, where it is crushed. Thence the ground malt,
or "grist" as it is now called, passes to the _Grist Hopper_, and from the
latter to the _Mashing Machine_, in which it is intimately mixed with hot
water from the _Hot Liquor Vessel_. From the mashing machine the mixed
grist and "liquor" pass to the _Mash-Tun_, where the starch of the malt is
rendered soluble. From the mash-tun the clear wort passes to the _Copper_,
where it is boiled with hops. From the copper the boiled wort passes to the
_Hop Back_, where the insoluble hop constituents are separated from the
wort. From the hop back the wort passes to the _Cooler_, from the latter to
the _Refrigerator_, thence (for the purpose of enabling the revenue
officers to assess the duty) to the _Collecting Vessel_,[4] and finally to
the _Fermenting Vessels_, in which the wort is transformed into "green"
beer. The latter is then cleansed, and finally racked and stored.

It will be seen from the above that brewing consists of seven distinct main
processes, which may be classed as follows: (1) Grinding; (2) Mashing; (3)
Boiling; (4) Cooling; (5) Fermenting; (6) Cleansing; (7) Racking and
Storing.

_Grinding_.--In most modern breweries the malt passes, on its way [v.04
p.0509] from the bins to the mill, through a cleaning and grading
apparatus, and then through an automatic measuring machine. The mills,
which exist in a variety of designs, are of the smooth roller type, and are
so arranged that the malt is _crushed_ rather than ground. If the malt is
ground too fine, difficulties arise in regard to efficient drainage in the
mash-tun and subsequent clarification. On the other hand, if the crushing
is too coarse the subsequent extraction of soluble matter in the mash-tun
is incomplete, and an inadequate yield results.

[Illustration: FIG. 1.--An 8-quarter Brewery (Messrs. L. Lumley & Co.,
Ltd.).]

[Illustration: FIG. 2.--Mash-tun with mashing machine.]

_Mashing_ is a process which consists mainly in extracting, by means of
water at an adequate temperature, the soluble matters pre-existent in the
malt, and in converting the insoluble starch and a great part of the
insoluble nitrogenous compounds into soluble and partly fermentable
products. Mashing is, without a doubt, the most important of the brewing
processes, for it is largely in the mash-tun that the character of the beer
to be brewed is determined. In modern practice the malt and the mashing
"liquor" (_i.e._ water) are introduced into the mash-tun simultaneously, by
means of the mashing machine (fig. 2, A). This is generally a cylindrical
metal vessel, commanding the mash-tun and provided with a central shaft and
screw. The grist (as the crushed malt is called) enters the mashing machine
from the grist case above, and the liquor is introduced at the back. The
screw is rotated rapidly, and so a thorough mixture of the grist and liquor
takes place as they travel along the mashing machine. The mash-tun (fig. 2)
is a large metal or wooden vessel, fitted with a false bottom composed of
plates perforated with numerous small holes or slits (C). This arrangement
is necessary in order to obtain a proper separation of the "wort" (as the
liquid portion of the finished mash is called) from the spent grains. The
mash-tun is also provided with a stirring apparatus (the _rakes_) so that
the grist and liquor may be intimately mixed (D), and an automatic
sprinkler, the _sparger_ (fig. 2, B, and fig. 3), which is employed in
order to wash out the wort remaining in the grains. The sparger consists of
a number of hollow arms radiating from a common centre and pierced by a
number of small perforations. The common central vessel from which the
sparge-arms radiate is mounted in such a manner that it rotates
automatically when a stream of water is admitted, so that a constant fine
spray covers the whole tun when the sparger is in operation. There are also
pipes for admitting "liquor" to the bottom of the tun, and for carrying the
wort from the latter to the "underback" or "copper."

The grist and liquor having been introduced into the tun (either by means
of the mashing machine or separately), the rakes are set going, so that the
mash may become thoroughly homogeneous, and after a short time the rakes
are stopped and the mash allowed to rest, usually for a period of about two
hours. After this, "taps are set"--_i.e._ communication is established
between the mash-tun and the vessel into which the wort runs--and the
sparger is started. In this manner the whole of the wort or extract is
separated from the grains. The quantity of water employed is, in all, from
two to three barrels to the quarter (336 lb) of malt.

In considering the process of mashing, one might almost say the process of
brewing, it is essential to remember that the type and quality of the beer
to be produced (see MALT) depends almost entirely (a) on the kind of malt
employed, and (b) on the mashing temperature. In other words, quality may
be controlled on the kiln or in the mash-tun, or both. Viewed in this
light, the following theoretical methods for preparing different types of
beer are possible:--(1) high kiln heats and high mashing temperatures; (2)
high kiln heats and low mashing temperatures; (3) low kiln heats and high
mashing temperatures; and (4) low kiln heats and low mashing temperatures.
In practice all these combinations, together with many intermediate ones,
are met with, and it is not too much to say that the whole science of
modern brewing is based upon them. It is plain, then, that the mashing
temperature will depend on the kind of beer that is to be produced, and on
the kind of malt employed. For stouts and black beers generally, a mashing
temperature of 148° to 150° F. is most usual; for pale or stock ales, 150°
to 154° F.; and for mild running beers, 154° to 149° F. The range of
temperatures employed in brewing English beers is a very limited one as
compared with foreign mashing methods, and does not range further,
practically speaking, than from 140° to 160° F. The effect of higher
temperatures is chiefly to cripple the enzyme or "ferment" diastase, which,
as already said, is the agent which converts the insoluble starch into
soluble dextrin, sugar and intermediate products. The higher the mashing
temperature, the more the diastase will be crippled in its action, and the
more dextrinous (non-fermentable) matter as compared with maltose
(fermentable sugar) will be formed. A pale or stock ale, which is a type of
beer that must be "dry" and that will keep, requires to contain a
relatively high proportion of dextrin and little maltose, and, in its
preparation, therefore, a high mashing temperature will be employed. On the
other hand, a mild running ale, which is a full, sweet beer, intended for
rapid consumption, will be obtained by means of low mashing temperatures,
which produce relatively little dextrin, but a good deal of maltose, _i.e._
sweet and readily fermentable matter.

[Illustration: FIG. 3.--Sparger.]

Diastase is not the only enzyme present in malt. There is also a ferment
which renders a part of the nitrogenous matter soluble. This again is
affected by temperature in much the same way as diastase. Low heats tend to
produce much non-coagulable [v.04 p.0510] nitrogenous matter, which is
undesirable in a stock beer, as it tends to produce fret and side
fermentations. With regard to the kind of malt and other materials employed
in producing various types of beer, pale ales are made either from pale
malt (generally a mixture of English and fine foreign, such as Smyrna,
California) only, or from pale malt and a little flaked maize, rice, invert
sugar or glucose. Running beers (mild ale) are made from a mixture of pale
and amber malts, sugar and flaked goods; stout, from a mixture of pale,
amber and roasted (black) malts only, or with the addition of a little
sugar or flaked maize.

When raw grain is employed, the process of mashing is slightly modified.
The maize, rice or other grain is usually gelatinized in a vessel (called a
_converter_ or _cooker_) entirely separated from the mash-tun, by means of
steam at a relatively high temperature, mostly with, but occasionally
without, the addition of some malt meal. After about half an hour the
gelatinized mass is mixed with the main mash, and this takes place shortly
before taps are set. This is possible inasmuch as the starch, being already
in a highly disintegrated condition, is very rapidly converted. By working
on the limited-decoction system (see below), it is possible to make use of
a fair percentage of raw grain in the mash-tun proper, thus doing away with
the "converter" entirely.

_The Filter Press Process._--The ordinary mash-tun process, as described
above, possesses the disadvantage that only coarse grists can be employed.
This entails loss of extract in several ways. To begin with, the sparging
process is at best a somewhat inefficient method for washing out the last
portions of the wort, and again, when the malt is at all hard or "steely,"
starch conversion is by no means complete. These disadvantages are overcome
by the filter press process, which was first introduced into Great Britain
by the Belgian engineer P. Meura. The malt, in this method of brewing, is
ground quite fine, and although an ordinary mash-tun may be used for
mashing, the separation of the clear wort from the solid matter takes place
in the filter press, which retains the very finest particles with ease. It
is also a simple matter to wash out the wort from the filter cake in the
presses, and experience has shown that markedly increased yields are thus
obtained. In the writer's opinion, there is little doubt that in the future
this, or a similar process, will find a very wide application.

_Boiling_.--From the mash-tun the wort passes to the _copper_. If it is not
possible to arrange the plant so that the coppers are situated beneath the
mash-tuns (as is the case in breweries arranged on the _gravitation
system_), an intermediate collecting vessel (the underback) is interposed,
and from this the wort is pumped into the copper. The latter is a large
copper vessel heated by direct fire or steam. Modern coppers are generally
closed in with a dome-shaped head, but many old-fashioned open coppers are
still to be met with, in fact pale-ale brewers prefer open coppers. In the
closed type the wort is frequently boiled under slight pressure. When the
wort has been raised to the boil, the hops or a part thereof are added, and
the boiling is continued generally from an hour to three hours, according
to the type of beer. The objects of boiling, briefly put, are: (1)
sterilization of the wort; (2) extraction from the hops of substances that
give flavour and aroma to the beer; (3) the coagulation and precipitation
of a part of the nitrogenous matter (the coagulable albuminoids), which, if
left in, would cause cloudiness and fret, &c., in the finished beer; (4)
the concentration of the wort. At least three distinct substances are
extracted from the hops in boiling. First, the _hop tannin_, which,
combining with a part of the proteids derived from the malt, precipitates
them; second, the _hop resin_, which acts as a preservative and bitter;
third, the _hop oil_, to which much of the fine aroma of beer is due. The
latter is volatile, and it is customary, therefore, not to add the whole of
the hops to the wort when it commences to boil, but to reserve about a
third until near the end of the copper stage. The quantity of hops employed
varies according to the type of beer, from about 3 lb to 15 lb per quarter
(336 lb) of malt. For mild ales and porters about 3 to 4 lb, for light pale
ales and light stouts 6 to 10 lb, and for strong ales and stouts 9 to 15 lb
of hops are employed.

_Cooling_.--When the wort has boiled the necessary time, it is turned into
the _hop back_ to settle. A hop back is a wooden or metal vessel, fitted
with a false bottom of perforated plates; the latter retain the spent hops,
the wort being drawn off into the coolers. After resting for a brief period
in the hop back, the bright wort is run into the _coolers_. The cooler is a
very shallow vessel of great area, and the result of the exposure of the
hot wort to a comparatively large volume of air is that a part of the hop
constituents and other substances contained in the wort are rendered
insoluble and are precipitated. It was formerly considered absolutely
essential that this hot aeration should take place, but in many breweries
nowadays coolers are not used, the wort being run direct from the hop back
to the refrigerator. There is much to be said for this procedure, as the
exposure of hot wort in the cooler is attended with much danger of
bacterial and wild yeast infection, but it is still a moot point whether
the cooler or its equivalent can be entirely dispensed with for all classes
of beers. A rational alteration would appear to be to place the cooler in
an air-tight chamber supplied with purified and sterilized air. This
principle has already been applied to the refrigerator, and apparently with
success. In America the cooler is frequently replaced by a cooling tank, an
enclosed vessel of some depth, capable of artificial aeration. It is not
practicable, in any case, to cool the wort sufficiently on the cooler to
bring it to the proper temperature for the fermentation stage, and for this
purpose, therefore, the _refrigerator_ is employed. There are several kinds
of refrigerators, the main distinction being that some are vertical, others
horizontal; but the principle in each case is much the same, and consists
in allowing a thin film or stream of wort to trickle over a series of pipes
through which cold water circulates. Fig. 5, Plate I., shows refrigerators,
employed in Messrs Allsopp's lager beer brewery, at work.

_Fermenting_.--By the process of fermentation the wort is converted into
beer. By the action of living yeast cells (see FERMENTATION) the sugar
contained in the wort is split up into alcohol and carbonic acid, and a
number of subsidiary reactions occur. There are two main systems of
fermentation, the _top fermentation_ system, which is that employed in the
United Kingdom, and the _bottom fermentation_ system, which is that used
for the production of beers of the continental ("lager") type. The wort,
generally at a temperature of about 60° F. (this applies to all the systems
excepting B [see below], in which the temperature is higher), is "pitched"
with liquid yeast (or "barm," as it is often called) at the rate of,
according to the type and strength of the beer to be made, 1 to 4 lb to the
barrel. After a few hours a slight froth or scum makes its appearance on
the surface of the liquid. At the end of a further short period this
develops into a light curly mass (_cauliflower_ or _curly head_), which
gradually becomes lighter and more solid in appearance, and is then known
as _rocky head_. This in its turn shrinks to a compact mass--the _yeasty
head_--which emits great bubbles of gas with a hissing sound. At this point
the _cleansing_ of the beer--_i.e._ the separation of the yeast from the
liquid--has fairly commenced, and it is let down (except in the skimming
and Yorkshire systems [see below]) into the pontos or unions, as the case
may be. During fermentation the temperature rises considerably, and in
order to prevent an excessive temperature being obtained (70-75° F. should
be the maximum) the fermenting vessels are fitted with "attemperators,"
_i.e._ a system of pipes through which cold water may be run.

_Cleansing_.--In England the methods of applying the top fermentation
system may be classified as follows: (A) _The Cleansing System_: (a)
Skimming System, (b) Dropping System (pontos or ordinary dropping system),
(c) Burton Union System. (B) _The Yorkshire Stone Square System_.

[Illustration: FIG. 4.--Fermenting Round.
A, Skimmer; B, Parachute; C, Attemperator.]

(A) In (a) the _Skimming System_ the fermentation from start to finish
takes place in wooden vessels (termed "squares" or "rounds"), fitted with
an attemperator and a parachute or other similar skimming device for
removing or "skimming" the yeast at the end of the fermentation (fig. 4).
The principle of (b) the _Dropping System_ is that the beer undergoes only
the main fermentation in the "round" or "square," and is then dropped down
into a second vessel or vessels, in which fermentation and cleansing are
completed. The _ponto_ system of dropping, which is now somewhat
old-fashioned, consists in discharging the beer into a series of vat-like
vessels, fitted with a peculiarly-shaped overflow lip. The yeast works its
way out of the vessel over the lip, and then flows into a gutter and is
collected. The pontos are kept filled with beer by means of a vessel placed
at a higher level. In the _ordinary_ dropping system the partly fermented
beer is let down from the "squares" and "rounds" into large vessels, termed
dropping or skimming "backs." These are fitted with attemperators, and
parachutes for the removal of yeast, in much the same way as in the
skimming system. As a rule the parachute covers the whole width of the
back. (c) The _Burton Union System_ is really an improved ponto system. A
series of casks, supplied with beer at the cleansing stage from a feed
vessel, are mounted so that they may rotate axially. Each cask is fitted
with an attemperator, a pipe and cock at the base for the removal of the
finished beer and "bottoms," and lastly with a swan neck fitting through a
bung-hole and commanding a common gutter. This system yields excellent
results for certain classes of beers, and many Burton brewers think it is
essential for obtaining [v.04 p.0511] the Burton character. Fig. 6 (Plate
II.) shows the process in operation in Messrs Allsopp's brewery.

(B) _The Stone Square System_, which is only used to a certain extent
(exclusively in the north of England), practically consists in pumping the
fermenting wort from one to the other of two superimposed square vessels,
connected with one another by means of a man-hole and a valve. These
squares are built of stone and kept very cool. At the end of the
fermentation the yeast (after closing the man-hole) is removed from the top
square.

_Racking, &c._--After the fermentation and cleansing operations are
completed, the beer is racked off (sometimes after passing a few hours in a
settling tank) into storage vessels or trade casks. The finest "stock" and
"pale" ales are stored from six weeks to three months prior to going out,
but "running" beers (mild ales, &c.) are frequently sent out of the brewery
within a week or ten days of mashing. It is usual to add some hops in cask
(this is called _dry hopping_) in the case of many of the better beers.
Running beers, which must be put into condition rapidly, or beers that have
become flat, are generally _primed_. Priming consists in adding a small
quantity of sugar solution to the beer in cask. This rapidly ferments and
so produces "condition."

_Fining_.--As a very light article is desired nowadays, and this has to be
provided in a short time, artificial means must be resorted to, in order to
replace the natural fining or brightening which storage brings about.
_Finings_ generally consist of a solution or semi-solution of isinglass in
sour beer, or in a solution of tartaric acid or of sulphurous acid. After
the finings are added to the beer and the barrels have been well rolled,
the finings slowly precipitate (or work out through the bung-hole) and
carry with them the matter which would otherwise render the beer turbid.

_Bottling_.--Formerly it was the general custom to brew a special beer for
bottling, and this practice is still continued by some brewers. It is
generally admitted that the special brew, matured by storage and an
adequate secondary fermentation, produces the best beer for bottling, but
the modern taste for a very light and bright bottled beer at a low cost has
necessitated the introduction of new methods. The most interesting among
these is the "chilling" and "carbonating" system. In this the beer, when it
is ripe for racking, is first "chilled," that is, cooled to a very low
temperature. As a result, there is an immediate deposition of much matter
which otherwise would require prolonged time to settle. The beer is then
filtered and so rendered quite bright, and finally, in order to produce
immediate "condition," is "carbonated," _i.e._ impregnated under pressure
with carbon dioxide (carbonic acid gas).

FOREIGN BREWING AND BEERS.--The system of brewing which differs most widely
from the English _infusion_ and _top fermentation_ method is the
_decoction_ and _bottom fermentation_ system, so widely employed, chiefly
on the continent of Europe, for the production of beers of the "lager"
type.

The method pursued in the decoction system is broadly as follows:--After
the grist has been mashed with cold water until a homogeneous mixture
ensues, sufficient hot water is introduced into the mash-tun to raise the
temperature to 85-100° F., according to circumstances. Thereupon, about
one-third of the mash (including the "goods") is transferred to the _Maisch
Kessel_ (mash copper), in which it is gradually brought to a temperature of
(about) 165° F., and this heat is maintained until the mash becomes
transparent. The _Dickmaische_, as this portion is called, is then raised
to the boil, and the ebullition sustained between a quarter and
three-quarters of an hour. Just sufficient of the _Dickmaische_ is returned
to the mash-tun proper to raise the temperature of the whole to 111-125°
F., and after a few minutes a third is again withdrawn and treated as
before, to form the second "thick mash." When the latter has been returned
to the mash-tun the whole is thoroughly worked up, allowed to stand in
order that the solids may deposit, and then another third (called the
_Läutermaische_ or "clear mash") is withdrawn, boiled until the coagulable
albuminoids are precipitated, and finally reconveyed to the mash-tun, where
the mashing is continued for some time, the final heat being rather over
160° F. The wort, after boiling with hops and cooling, much as in the
English system, is subjected to the peculiar system of fermentation called
_bottom fermentation_. In this system the "pitching" and fermentation take
place at a very low temperature and, compared with the English system, in
very small vessels. The fermenting cellars are maintained at a temperature
of about 37-38° F., and the temperature of the fermenting wort does not
rise above 50° F. The yeast, which is of a different type from that
employed in the English system, remains at the bottom of the fermenting
tun, and hence is derived the name of "bottom fermentation" (see
FERMENTATION). The primary fermentation lasts about eleven to twelve days
(as compared with three days on the English system), and the beer is then
run into store (lager) casks where it remains at a temperature approaching
the freezing-point of water for six weeks to six months, according to the
time of the year and the class of the beer. As to the relative character
and stability of decoction and infusion beers, the latter are, as a rule,
more alcoholic; but the former contain more unfermented malt extract, and
are therefore, broadly speaking, more nutritive. Beers of the German type
are less heavily hopped and more peptonized than English beers, and more
highly charged with carbonic acid, which, owing to the low fermentation and
storing temperatures, is retained for a comparatively long time and keeps
the beer in condition. On the other hand, infusion beers are of a more
stable and stimulating character. It is impossible to keep "lager" beer on
draught in the ordinary sense of the term in England. It will not keep
unless placed on ice, and, as a matter of fact, the "condition" of lager is
dependent to a far greater extent on the methods of distribution and
storage than is the case with infusion beers. If a cask is opened it must
be rapidly consumed; indeed it becomes undrinkable within a very few hours.
The gas escapes rapidly when the pressure is released, the temperature
rises, and the beer becomes flat and mawkish. In Germany every publican is
bound to have an efficient supply of ice, the latter frequently being
delivered by the brewery together with the beer.

In America the common system of brewing is one of infusion mashing combined
with bottom fermentation. The method of mashing, however, though on
infusion lines, differs appreciably from the English process. A very low
initial heat--about 100° F.--at which the mash remains for about an hour,
is employed. After this the temperature is rapidly raised to 153-156° F. by
running in the boiling "cooker mash," _i.e._ raw grain wort from the
converter. After a period the temperature is gradually increased to about
165° F. The very low initial heat, and the employment of relatively large
quantities of readily transformable malt adjuncts, enable the American
brewer to make use of a class of malt which would be considered quite unfit
for brewing in an English brewery. The system of fermentation is very
similar to the continental "lager" system, and the beer obtained bears some
resemblance to the German product. To the English palate it is somewhat
flavourless, but it is always retailed in exceedingly brilliant condition
and at a proper temperature. There can be little doubt that every nation
evolves a type of beer most suited to its climate and the temperament of
the people, and in this respect the modern American beer is no exception.
In regard to plant and mechanical arrangements generally, the modern
American breweries may serve as an object-lesson to the European brewer,
although there are certainly a number of breweries in the United Kingdom
which need not fear comparison with the best American plants.

It is a sign of the times and further evidence as to the growing taste for
a lighter type of beer, that lager brewing in its most modern form has now
fairly taken root in Great Britain, and in this connexion the process
introduced by Messrs Allsopp exhibits many features of interest. The
following is a brief description of the plant and the methods
employed:--The wort is prepared on infusion lines, and is then cooled by
means of refrigerated brine before passing to a temporary store tank, which
serves as a gauging vessel. From the latter the wort passes directly to the
fermenting tuns, huge closed cylindrical vessels made of sheet-steel and
coated with glass enamel. There the wort ferments under reduced pressure,
the carbonic acid generated being removed by means of a vacuum pump, and
the gas thus withdrawn is replaced by the introduction of cool sterilized
air. The fermenting cellars are kept at 40° F. The yeast employed is a pure
culture (see FERMENTATION) bottom yeast, but the withdrawal of the products
of yeast metabolism and the constant supply of pure fresh air cause the
fermentation to proceed far more rapidly than is the case with lager beer
brewed on ordinary lines. It is, in fact, finished in about six days.
Thereupon the air-supply is cut off, the green beer again cooled to 40° F.
and [v.04 p.0512] then conveyed by means of filtered air pressure to the
store tanks, where secondary fermentation, lasting three weeks, takes
place. The gases evolved are allowed to collect under pressure, so that the
beer is thoroughly charged with the carbonic acid necessary to give it
condition. Finally the beer is again cooled, filtered, racked and bottled,
the whole of these operations taking place under counter pressure, so that
no gas can escape; indeed, from the time the wort leaves the copper to the
moment when it is bottled in the shape of beer, it does not come into
contact with the outer air.

The preparation of the Japanese beer _saké_ (_q.v._) is of interest. The
first stage consists in the preparation of _Koji_, which is obtained by
treating steamed rice with a culture of _Aspergillus oryzae_. This
micro-organism converts the starch into sugar. The _Koji_ is converted into
_moto_ by adding it to a thin paste of fresh-boiled starch in a vat.
Fermentation is set up and lasts for 30 to 40 days. The third stage
consists in adding more rice and _Koji_ to the _moto_, together with some
water. A secondary fermentation, lasting from 8 to 10 days, ensues.
Subsequently the whole is filtered, heated and run into casks, and is then
known as _saké_. The interest of this process consists in the fact that a
single micro-organism--a mould--is able to exercise the combined functions
of saccharification and fermentation. It replaces the diastase of malted
grain and also the yeast of a European brewery. Another liquid of interest
is _Weissbier_. This, which is largely produced in Berlin (and in some
respects resembles the _wheat-beer_ produced in parts of England), is
generally prepared from a mash of three parts of wheat malt and one part of
barley malt. The fermentation is of a symbiotic nature, two organisms,
namely a yeast and a fission fungus (the _lactic acid bacillus_) taking
part in it. The preparation of this peculiar double ferment is assisted by
the addition of a certain quantity of white wine to the yeast prior to
fermentation.

BREWING CHEMISTRY.--The principles of brewing technology belong for the
most part to physiological chemistry, whilst those of the cognate industry,
malting, are governed exclusively by that branch of knowledge. Alike in
following the growth of barley in field, its harvesting, maturing and
conversion into malt, as well as the operations of mashing malt, fermenting
wort, and conditioning beer, physiological chemistry is needed. On the
other hand, the consideration of the saline matter in waters, the
composition of the extract of worts and beers, and the analysis of brewing
materials and products generally, belong to the domain of pure chemistry.
Since the extractive matters contained in wort and beer consist for the
most part of the transformation products of starch, it is only natural that
these should have received special attention at the hands of scientific men
associated with the brewing industry. It was formerly believed that by the
action of diastase on starch the latter is first converted into a gummy
substance termed dextrin, which is then subsequently transformed into a
sugar--glucose. F.A. Musculus, however, in 1860, showed that sugar and
dextrin are simultaneously produced, and between the years 1872 and 1876
Cornelius O'Sullivan definitely proved that the sugar produced was maltose.
When starch-paste, the jelly formed by treating starch with boiling water,
is mixed with iodine solution, a deep blue coloration results. The first
product of starch degradation by either acids or diastase, namely soluble
starch, also exhibits the same coloration when treated with iodine. As
degradation proceeds, and the products become more and more soluble and
diffusible, the blue reaction with iodine gives place first to a purple,
then to a reddish colour, and finally the coloration ceases altogether. In
the same way, the optical rotating power decreases, and the cupric reducing
power (towards Fehling's solution) increases, as the process of hydrolysis
proceeds. C. O'Sullivan was the first to point out definitely the influence
of the temperature of the mash on the character of the products. The work
of Horace T. Brown (with J. Heron) extended that of O'Sullivan, and (with
G.H. Morris) established the presence of an intermediate product between
the higher dextrins and maltose. This product was termed maltodextrin, and
Brown and Morris were led to believe that a large number of these
substances existed in malt wort. They proposed for these substances the
generic name "amyloins." Although according to their view they were
compounds of maltose and dextrin, they had the properties of mixtures of
these two substances. On the assumption of the existence of these
compounds, Brown and his colleagues formulated what is known as the
maltodextrin or amyloin hypothesis of starch degradation. C.J. Lintner, in
1891, claimed to have separated a sugar, isomeric with maltose, which is
termed isomaltose, from the products of starch hydrolysis. A.R. Ling and
J.L. Baker, as well as Brown and Morris, in 1895, proved that this
isomaltose was not a homogeneous substance, and evidence tending to the
same conclusion was subsequently brought forward by continental workers.
Ling and Baker, in 1897, isolated the following compounds from the products
of starch hydrolysis--maltodextrin-[alpha], C_{36}H_{62}O_{31}, and
maltodextrin-[beta], C_{24}H_{42}O_{21} (previously named by Prior,
achroodextrin III.). They also separated a substance, C_{12}H_{22}O_{11},
isomeric with maltose, which had, however, the characteristics of a
dextrin. This is probably identical with the so-called dextrinose isolated
by V. Syniewski in 1902, which yields a phenylosazone melting at 82-83° C.
It has been proved by H. Ost that the so-called isomaltose of Lintner is a
mixture of maltose and another substance, maltodextrin, isomeric with Ling
and Baker's maltodextrin-[beta].

The theory of Brown and Morris of the degradation of starch, although based
on experimental evidence of some weight, is by no means universally
accepted. Nevertheless it is of considerable interest, as it offers a
rational and consistent explanation of the phenomena known to accompany the
transformation of starch by diastase, and even if not strictly correct it
has, at any rate, proved itself to be a practical working hypothesis, by
which the mashing and fermenting operations may be regulated and
controlled. According to Brown and Morris, the starch molecule consists of
five amylin groups, each of which corresponds to the molecular formula
(C_{12}H_{20}O_{10})_{20}. Four of these amylin radicles are grouped
centrally round the fifth, thus:--

(C_{12}H_{20}O_{10})_{20} (C_{12}H_{20}O_{10})_{20}
\ /
(C_{12}H_{20}O_{10})_{20}
/ \
(C_{12}H_{20}O_{10})_{20} (C_{12}H_{20}O_{10})_{20}

By the action of diastase, this complex molecule is split up, undergoing
hydrolysis into four groups of amyloins, the fifth or central group
remaining unchanged (and under brewing conditions unchangeable), forming
the substance known as stable dextrin. When diastase acts on starch-paste,
hydrolysis proceeds as far as the reaction represented by the following
equation:--

5(C_{12}H_{20}O_{10})_{20} + 80 H_2O
starch. water.
= 80 C_{12}H_{22}O_{11} + (C_{12}H_{20}O_{10})_{20}
maltose. stable dextrin.

The amyloins are substances containing varying numbers of amylin (original
starch or dextrin) groups in conjunction with a proportional number of
maltose groups. They are not separable into maltose and dextrin by any of
the ordinary means, but exhibit the properties of mixtures of these
substances. As the process of hydrolysis proceeds, the amyloins become
gradually poorer in amylin and relatively richer in maltose-groups. The
final products of transformation, according to Brown and J.H. Millar, are
maltose and glucose, which latter is derived from the hydrolysis of the
stable dextrin. This theory may be applied in practical brewing in the
following manner. If it is desired to obtain a beer of a stable
character--that is to say, one containing a considerable proportion of
high-type amyloins--it is necessary to restrict the action of the diastase
in the mash-tun accordingly. On the other hand, for mild running ales,
which are to "condition" rapidly, it is necessary to provide for the
presence of sufficient maltodextrin of a low type. Investigation has shown
that the type of maltodextrin can be regulated, not only in the mash-tun
but also on the malt-kiln. A higher type is obtained by low kiln and high
mashing temperatures than by high kiln and low mashing heats, and it is
possible therefore to regulate, on scientific lines, not only the quality
but also the type of amyloins which are suitable for a particular beer.

The chemistry of the nitrogenous constituents of malt is equally important
with that of starch and its transformations. Without nitrogenous compounds
of the proper type, vigorous fermentations are not possible. It may be
remembered that yeast assimilates nitrogenous compounds in some of their
simpler forms--amides and the like. One of the aims of the maltster is,
therefore, to break down the protein substances present in barley to such a
degree that the wort has a maximum nutritive value for the yeast. Further,
it is necessary for the production of stable beer to eliminate a large
proportion of nitrogenous matter, and this is only done by the yeast when
the proteins are degraded. There is also some evidence that the presence of
albumoses assists in producing the foaming properties of beer. It has now
been established definitely, by the work of A. Fernbach, W. Windisch,
F.Weiss and P. Schidrowitz, that finished malt contains at least two
proteolytic enzymes (a peptic and a pancreatic enzyme).

[Illustration: BREWING

PLATE I.

FIG. 5.--REFRIGERATORS IN "LAGER" BREWERY OF MESSRS. ALLSOPP.

The hot wort trickles over the outside of the series of pipes, and is
cooled by the cold water which circulates in them. From the shallow
collecting trays the cooled wort is conducted to the fermenting backs.]

[Illustration: BREWING

PLATE II.

FIG. 6.--BURTON-UNION SYSTEM OF CLEANSING. (MESSRS. ALLSOPP'S BREWERY.)

The green beer is filled into the casks, and the excess of yeast, &c., then
works out through the swan necks into the long common gutter shown.]

[v.04 p.0513]

The presence of different types of phosphates in malt, and the important
influence which, according to their nature, they exercise in the brewing
process by way of the enzymes affected by them, have been made the subject
of research mainly by Fernbach and A. Hubert, and by P.E. Petit and G.
Labourasse. The number of enzymes which are now known to take part in the
brewing process is very large. They may with utility be grouped as
follows:--

Name. Rôle or Nature.
+- Cytase Dissolves cell walls of
| of starch granules.
In the malt ----+- Diastase A Liquefies starch
or mash-tun. +- Diastase B Saccharifies starch.
+- Proteolytic Enzymes -+- (1) Peptic.
| +- (2) Pancreatic.
+- Catalase Splits peroxides.

In fermenting +- Invertase Inverts cane sugar.
wort and -----+- Glucase Splits maltose into glucose.
yeast. +- Zymase Splits sugar into alcohol
and carbonic acid.

BIBLIOGRAPHY.--W.J. Sykes, _Principles and Practice of Brewing_ (London,
1897); Moritz and Morris, _A Text-book of the Science of Brewing_ (London,
1891); H.E. Wright, _A Handy Book for Brewers_ (London, 1897); Frank
Thatcher, _Brewing and Malting_ (London, 1898); Julian L. Baker, _The
Brewing Industry_ (London, 1905); E.J. Lintner, _Grundriss der
Bierbrauerei_ (Berlin, 1904); J.E. Thausing, _Die Theorie und Praxis der
Malzbereitung und Bierfabrikation_ (Leipzig, 1898); E. Michel, _Lehrbuch
der Bierbrauerei_ (Augsburg, 1900); E. Prior, _Chemie u. Physiologie des
Malzes und des Bieres_ (Leipzig, 1896). Technical journals: _The Journal of
the Institute of Brewing_ (London); _The Brewing Trade Review_ (London);
_The Brewers' Journal_ (London); _The Brewers' Journal_ (New York);
_Wochenschrift für Brauerei_ (Berlin); _Zeitschrift für das gesammte
Brauwesen_ (Munich).

(P. S.)

[1] They were classified at 28 lb in 1896, but since 1897 the standard has
been at the rate of 32 lb to the bushel.

[2] Inclusive of rice and maize.

[3] Exclusive of rice and maize.

[4] As a rule there is no separate "collecting vessel," duty being assessed
in the fermenting vessels.

BREWSTER, SIR DAVID (1781-1868), Scottish natural philosopher, was born on
the 11th of December 1781 at Jedburgh, where his father, a teacher of high
reputation, was rector of the grammar school. At the early age of twelve he
was sent to the university of Edinburgh, being intended for the clerical
profession. Even before this, however, he had shown a strong inclination
for natural science, and this had been fostered by his intimacy with a
"self-taught philosopher, astronomer and mathematician," as Sir Walter
Scott called him, of great local fame--James Veitch of Inchbonny, who was
particularly skilful in making telescopes. Though he duly finished his
theological course and was licensed to preach, Brewster's preference for
other pursuits prevented him from engaging in the active duties of his
profession. In 1799 he was induced by his fellow-student, Henry Brougham,
to study the diffraction of light. The results of his investigations were
communicated from time to time in papers to the _Philosophical
Transactions_ of London and other scientific journals, and were admirably
and impartially summarized by James D. Forbes in his preliminary
dissertation to the eighth edition of the _Encyclopaedia Britannica_. The
fact that other philosophers, notably Etienne Louis Malus and Augustin
Fresnel, were pursuing the same investigations contemporaneously in France
does not invalidate Brewster's claim to independent discovery, even though
in one or two cases the priority must be assigned to others.

The most important subjects of his inquiries are enumerated by Forbes under
the following five heads:--(1) The laws of polarization by reflection and
refraction, and other quantitative laws of phenomena; (2) The discovery of
the polarizing structure induced by heat and pressure; (3) The discovery of
crystals with two axes of double refraction, and many of the laws of their
phenomena, including the connexion of optical structure and crystalline
forms; (4) The laws of metallic reflection; (5) Experiments on the
absorption of light. In this line of investigation the prime importance
belongs to the discovery (1) of the connexion between the refractive index
and the polarizing angle, (2) of biaxial crystals, and (3) of the
production of double refraction by irregular heating. These discoveries
were promptly recognized. So early as the year 1807 the degree of LL.D. was
conferred upon Brewster by Marischal College, Aberdeen; in 1815 he was made
a member of the Royal Society of London, and received the Copley medal; in
1818 he received the Rumford medal of the society; and in 1816 the French
Institute awarded him one-half of the prize of three thousand francs for
the two most important discoveries in physical science made in Europe
during the two preceding years. Among the non-scientific public his fame
was spread more effectually by his rediscovery about 1815 of the
kaleidoscope, for which there was a great demand in both England and
America. An instrument of higher interest, the stereoscope, which, though
of much later date (1849-1850), may be mentioned here, since along with the
kaleidoscope it did more than anything else to popularize his name, was
not, as has often been asserted, the invention of Brewster. Sir Charles
Wheatstone discovered its principle and applied it as early as 1838 to the
construction of a cumbrous but effective instrument, in which the binocular
pictures were made to combine by means of mirrors. To Brewster is due the
merit of suggesting the use of lenses for the purpose of uniting the
dissimilar pictures; and accordingly the lenticular stereoscope may fairly
be said to be his invention. A much more valuable practical result of
Brewster's optical researches was the improvement of the British lighthouse
system. It is true that the dioptric apparatus was perfected independently
by Fresnel, who had also the satisfaction of being the first to put it into
operation. But it is indisputable that Brewster was earlier in the field
than Fresnel; that he described the dioptric apparatus in 1812; that he
pressed its adoption on those in authority at least as early as 1820, two
years before Fresnel suggested it; and that it was finally introduced into
British lighthouses mainly by his persistent efforts.

Brewster's own discoveries, important though they were, were not his only,
perhaps not even his chief, service to science. He began literary work in
1799 as a regular contributor to the _Edinburgh Magazine_, of which he
acted as editor at the age of twenty. In 1807 he undertook the editorship
of the newly projected _Edinburgh Encyclopaedia_, of which the first part
appeared in 1808, and the last not until 1830. The work was strongest in
the scientific department, and many of its most valuable articles were from
the pen of the editor. At a later period he was one of the leading
contributors to the _Encyclopaedia Britannica_ (seventh and eighth
editions), the articles on Electricity, Hydrodynamics, Magnetism,
Microscope, Optics, Stereoscope, Voltaic Electricity, &c., being from his
pen. In 1819 Brewster undertook further editorial work by establishing, in
conjunction with Robert Jameson (1774-1854), the _Edinburgh Philosophical
Journal_, which took the place of the _Edinburgh Magazine_. The first ten
volumes (1819-1824) were published under the joint editorship of Brewster
and Jameson, the remaining four volumes (1825-1826) being edited by Jameson
alone. After parting company with Jameson, Brewster started the _Edinburgh
Journal of Science_ in 1824, sixteen volumes of which appeared under his
editorship during the years 1824-1832, with very many articles from his own
pen. To the transactions of various learned societies he contributed from
first to last between three and four hundred papers, and few of his
contemporaries wrote so much for the various reviews. In the _North British
Review_ alone seventy-five articles of his appeared. A list of his larger
separate works will be found below. Special mention, however, must be made
of the most important of them all--his biography of Sir Isaac Newton. In
1831 he published a short popular account of the philosopher's life in
Murray's _Family Library_; but it was not until 1855 that he was able to
issue the much fuller _Memoirs of the Life, Writings and Discoveries of Sir
Isaac Newton_, a work which embodied the results of more than twenty years'
patient investigation of original manuscripts and all other available
sources.

Brewster's relations as editor brought him into frequent communication with
the most eminent scientific men, and he was naturally among the first to
recognize the benefit that would accrue from regular intercourse among
workers in the field of science. In an article in the _Quarterly Review_ he
threw out a suggestion for "an association of our nobility, clergy, gentry
and philosophers," which was taken up by others and found speedy
realization in the British Association for the Advancement of [v.04 p.0514]
Science. Its first meeting was held at York in 1831; and Brewster, along
with Charles Babbage and Sir John F. W. Herschel, had the chief part in
shaping its constitution. In the same year in which the British Association
held its first meeting, Brewster received the honour of knighthood and the
decoration of the Guelphic order of Hanover. In 1838 he was appointed
principal of the united colleges of St Salvator and St Leonard, St Andrews.
In 1849 he acted as president of the British Association and was elected
one of the eight foreign associates of the Institute of France in
succession to J.J. Berzelius; and ten years later he accepted the office of
principal of the university of Edinburgh, the duties of which he discharged
until within a few months of his death, which took place at Allerly,
Melrose, on the 10th of February 1868.

In estimating Brewster's place among scientific discoverers the chief thing
to be borne in mind is that the bent of his genius was not
characteristically mathematical. His method was empirical, and the laws
which he established were generally the result of repeated experiment. To
the ultimate explanation of the phenomena with which he dealt he
contributed nothing, and it is noteworthy in this connexion that if he did
not maintain to the end of his life the corpuscular theory he never
explicitly adopted the undulatory theory of light. Few will be inclined to
dispute the verdict of Forbes:--"His scientific glory is different in kind
from that of Young and Fresnel; but the discoverer of the law of
polarization of biaxial crystals, of optical mineralogy, and of double
refraction by compression, will always occupy a foremost rank in the
intellectual history of the age." In addition to the various works of
Brewster already noticed, the following may be mentioned:--Notes and
Introduction to Carlyle's translation of Legendre's _Elements of Geometry_
(1824); _Treatise on Optics_ (1831); _Letters on Natural Magic,_ addressed
to Sir Walter Scott (1831); _The Martyrs of Science, or the Lives of
Galileo, Tycho Brahe, and Kepler_ (1841); _More Worlds than One_ (1854).

See _The Home Life of Sir David Brewster,_ by his daughter Mrs Gordon.

BREWSTER, WILLIAM (c. 1566-1644), American colonist, one of the leaders of
the "Pilgrims," was born at Scrooby, in Nottinghamshire, England, about
1566. After studying for a short time at Cambridge, he was from 1584 to
1587 in the service of William Davison (? 1541-1608), who in 1585 went to
the Low Countries to negotiate an alliance with the states-general and in
1586 became assistant to Walsingham, Queen Elizabeth's secretary of state.
Upon the disgrace of Davison, Brewster removed to Scrooby, where from 1590
until September 1607 he held the position of "Post," or postmaster
responsible for the relays of horses on the post road, having previously,
for a short time, assisted his father in that office. About 1602 his
neighbours began to assemble for worship at his home, the Scrooby manor
house, and in 1606 he joined them in organizing the Separatist church of
Scrooby. After an unsuccessful attempt in 1607 (for which he was imprisoned
for a short time), he, with other Separatists, removed to Holland in 1608
to obtain greater freedom of worship. At Leiden in 1609 he was chosen
ruling elder of the Congregation. In Holland he supported himself first by
teaching English and afterwards in 1616-1619, as the partner of one Thomas
Brewer, by secretly printing, for sale in England, books proscribed by the
English government, thus, says Bradford, having "imploymente inough." In
1619 their types were seized and Brewer was arrested by the authorities of
the university of Leiden, acting on the instance of the British ambassador,
Sir Dudley Carleton. Brewster, however, escaped, and in the same year, with
Robert Cushman (c. 1580-1625), obtained in London, on behalf of his
associates, a land patent from the Virginia Company. In 1620 he emigrated
to America on the "Mayflower," and was one of the founders of the Plymouth
Colony. Here besides continuing until his death to act as ruling elder, he
was also--regularly until the arrival of the first pastor, Ralph Smith (d.
1661), in 1629 and irregularly afterward--a "teacher," preaching "both
powerfully and profitably to ye great contentment of ye hearers and their
comfortable edification." By many he is regarded as pre-eminently the
leader of the "Pilgrims." He died, probably on the 10th of April 1644.

See Ashbel Steele's _Chief of the Pilgrims; or the Life and Time of William
Brewster_ (Philadelphia, 1857); and a sketch in William Bradford's _History
of the Plimouth Plantation_ (new ed., Boston, 1898).

BRÉZÉ the name of a noble Angevin family, the most famous member of which
was PIERRE DE BRÉZÉ (c. 1410-1465), one of the trusted soldiers and
statesmen of Charles VII. He had made his name as a soldier in the English
wars when in 1433 he joined with Yolande, queen of Sicily, the constable
Richmond and others, in chasing from power Charles VII.'s minister La
Trémoille. He was knighted by Charles of Anjou in 1434, and presently
entered the royal council. In 1437 he became seneschal of Anjou, and in
1440 of Poitou. During the Praguerie he rendered great service to the royal
cause against the dauphin Louis and the revolted nobles, a service which
was remembered against him after Louis's accession to the throne. He fought
against the English in Normandy in 1440-1441, and in Guienne in 1442. In
the next year he became chamberlain to Charles VII., and gained the chief
power in the state through the influence of Agnes Sorel, superseding his
early allies Richmond and Charles of Anjou. The six years (1444-1450) of
his ascendancy were the most prosperous period of the reign of Charles VII.
His most dangerous opponent was the dauphin Louis, who in 1448 brought
against him accusations which led to a formal trial resulting in a complete
exoneration of Brézé and his restoration to favour. He fought in Normandy
in 1450-1451, and became seneschal of the province after the death of Agnes
Sorel and the consequent decline of his influence at court. He made an
ineffective descent on the English coast at Sandwich in 1457, and was
preparing an expedition in favour of Margaret of Anjou when the accession
of Louis XI. brought him disgrace and a short imprisonment. In 1462,
however, his son Jacques married Louis's half-sister, Charlotte de Valois,
daughter of Agnes Sorel. In 1462 he accompanied Margaret to Scotland with a
force of 2000 men, and after the battle of Hexham he brought her back to
Flanders. On his return he was reappointed seneschal of Normandy, and fell
in the battle of Montlhéry on the 16th of July 1465. He was succeeded as
seneschal of Normandy by his eldest son Jacques de Brézé (c. 1440-1490),
count of Maulevrier; and by his grandson, husband of the famous Diane de
Poitiers, Louis de Brézé (d. 1531), whose tomb in Rouen cathedral,
attributed to Jean Goujon and Jean Cousin, is a splendid example of French
Renaissance work.

The lordship of Brézé passed eventually to Claire Clémence de Maillé,
princess of Condé, by whom it was sold to Thomas Dreux, who took the name
of Dreux Brézé, when it was erected into a marquisate. HENRI EVRARD,
marquis de Dreux-Brézé (1762-1829), succeeded his father as master of the
ceremonies to Louis XVI. in 1781. On the meeting of the states-general in
1789 it fell to him to regulate the questions of etiquette and precedence
between the three estates. That as the immediate representative of the
crown he should wound the susceptibilities of the deputies was perhaps
inevitable, but little attempt was made to adapt traditional etiquette to
changed circumstances. Brézé did not formally intimate to President Bailly
the proclamation of the royal séance until the 20th of June, when the
carpenters were about to enter the hall to prepare for the event, thus
provoking the session in the tennis court. After the royal séance Brézé was
sent to reiterate Louis's orders that the estates should meet separately,
when Mirabeau replied that the hall could not be cleared except by force.
After the fall of the Tuileries Brézé emigrated for a short time, but
though he returned to France he was spared during the Terror. At the
Restoration he was made a peer of France, and resumed his functions as
guardian of an antiquated ceremonial. He died on the 27th of January 1829,
when he was succeeded in the peerage and at court by his son Scipion
(1793-1845).

The best contemporary account of Pierre de Brézé is given in the
_Chroniques_ of the Burgundian chronicler, Georges Chastellain, who had
been his secretary. Chastellain addressed a _Déprécation_ to Louis XI. on
his behalf at the time of his disgrace.

[v.04 p.0515] BRIALMONT, HENRI ALEXIS (1821-1903), Belgian general and
military engineer, son of General Laurent Mathieu Brialmont (d. 1885), was
born at Venlo in Limburg on the 25th of May 1821. Educated at the Brussels
military school, he entered the army as sub-lieutenant of engineers in
1843, and became lieutenant in 1847. From 1847 to 1850 he was private
secretary to the war minister, General Baron Chazal. In 1855 he entered the
staff corps, became major in 1861, lieutenant-colonel 1864, colonel in 1868
and major-general 1874. In this rank he held at first the position of
director of fortifications in the Antwerp district (December 1874), and
nine months later he became inspector-general of fortifications and of the
corps of engineers. In 1877 he became lieutenant-general. His far-reaching
schemes for the fortification of the Belgian places met with no little
opposition, and Brialmont seems to have felt much disappointment in this;
at any rate he went in 1883 to Rumania to advise as to the fortification
works required for the defence of the country, and presided over the
elaboration of the scheme by which Bucharest was to be made a first-class
fortress. He was thereupon placed _en disponibilité_ in his own service, as
having undertaken the Bucharest works without the authorization of his
sovereign. This was due in part to the suggestion of Austria, which power
regarded the Bucharest works as a menace to herself. His services were,
however, too valuable to be lost, and on his return to Belgium in 1884 he
resumed his command of the Antwerp military district. He had, further,
while in eastern Europe, prepared at the request of the Hellenic
government, a scheme for the defence of Greece. He retired in 1886, but
continued to supervise the Rumanian defences. He died on the 21st of
September 1903.

In the first stage of his career as an engineer Brialmont's plans followed
with but slight modification the ideas of Vauban; and his original scheme
for fortifying Antwerp provided for both enceinte and forts being on a
bastioned trace. But in 1859, when the great entrenched camp at Antwerp was
finally taken in hand, he had already gone over to the school of polygonal
fortification and the ideas of Montalembert. About twenty years later
Brialmont's own types and plans began to stand out amidst the general
confusion of ideas on fortification which naturally resulted from the
introduction of long-range guns, and from the events of 1870-71. The
extreme detached forts of the Antwerp region and the fortifications on the
Meuse at Liége and Namur were constructed in accordance with Brialmont's
final principles, viz. the lavish use of armour to protect the artillery
inside the forts, the suppression of all artillery positions open to
overhead fire, and the multiplication of intermediate batteries (see
FORTIFICATION AND SIEGECRAFT). In his capacity of inspector-general
Brialmont drafted and carried out the whole scheme for the defences of
Belgium. He was an indefatigable writer, and produced, besides essays,
reviews and other papers in the journals, twenty-three important works and
forty-nine pamphlets. In 1850 he originated the _Journal de l'armée Belge_.
His most important publications were _La Fortification du temps présent_
(Brussels, 1885); _Influence du tir plongeant et des obus-torpilles sur la
fortification_ (Brussels, 1888); _Les Régions fortifiées_ (Brussels, 1890);
_La Défense des états et la fortification à la fin du XIX^e siècle_
(Brussels, 1895); _Progrès de la défense des états et de la fortification
permanente depuis Vauban_ (Brussels, 1898).

BRIAN (926-1014), king of Ireland, known as BRIAN BORU, BOROMA, or BOROIMHE
(from _boroma_, an Irish word for tribute), was a son of a certain Kennedy
or Cenneide (d. 951). He passed his youth in fighting against the Danes,
who were constantly ravaging Munster, the northern part of which district
was the home of Brian's tribe, and won much fame in these encounters. In
976 his brother, Mathgamhain or Mahon, who had become king of Thomond about
951 and afterwards king of Munster, was murdered; Brian avenged this deed,
became himself king of Munster in 978, and set out upon his career of
conquest. He forced the tribes of Munster and then those of Leinster to own
his sovereignty, defeated the Danes, who were established around Dublin, in
Wicklow, and marched into Dublin, and after several reverses compelled
Malachy (Maelsechlainn), the chief king of Ireland, who ruled in Meath, to
bow before him in 1002. Connaught was his next objective. Here and also in
Ulster he was successful, everywhere he received hostages and tribute, and
he was generally recognized as the _ardri_, or chief king of Ireland. After
a period of comparative quiet Brian was again at war with the Danes of
Dublin, and on the 23rd of April 1014 his forces gained a great victory
over them at Clontarf. After this battle, however, the old king was slain
in his tent, and was buried at Armagh. Brian has enjoyed a great and not
undeserved reputation. One of his charters is still preserved in Trinity
College, Dublin.

See E.A. D'Alton, _History of Ireland_, vol. i. (1903).

BRIANÇON, a strongly fortified town in the department of Hautes-Alpes in
S.E. France. It is built at a height of 4334 ft. on a plateau which
dominates the junction of the Durance with the Guisane. The town itself is
formed of very steep and narrow, though picturesque streets. As it lies at
the foot of the descent from the Mont Genèvre Pass, giving access to Turin,
a great number of fortifications have been constructed on the heights
around Briançon, especially towards the east. The Fort Janus is no less
than 4000 ft. above the town. The parish church, with its two towers, was
built 1703-1726, and occupies a very conspicuous position. The Pont
d'Asfeld, E. of the town, was built in 1734, and forms an arch of 131 ft.
span, thrown at a height of 184 ft. across the Durance. The modern town
extends in the plain at the S.W. foot of the plateau on which the old town
is built and forms the suburb of Ste Catherine, with the railway station,
and an important silk-weaving factory. Briançon is 51½ m. by rail from Gap.
The commune had a civil population in 1906 of 4883 (urban population 3130),
while the permanent garrison was 2641--in all 7524 inhabitants.

Briançon was the _Brigantium_ of the Romans and formed part of the kingdom
of King Cottius. About 1040 it came into the hands of the counts of Albon
(later dauphins of the Viennois) and thenceforth shared the fate of the
Dauphiné. The Briançonnais included not merely the upper valley of the
Durance (with those of its affluents, the Gyronde and the Guil), but also
the valley of the Dora Riparia (Césanne, Oulx, Bardonnèche and Exilles),
and that of the Chisone (Fénestrelles, Pérouse, Pragelas)--these glens all
lying on the eastern slope of the chain of the Alps. But by the treaty of
Utrecht (1713) all these valleys were handed over to Savoy in exchange for
that of Barcelonnette, on the west slope of the Alps. In 1815 Briançon
successfully withstood a siege of three months at the hands of the Allies,
a feat which is commemorated by an inscription on one of its gates, _Le
passé répond de l'avenir_.

(W. A. B. C.)

BRIAND, ARISTIDE (1862- ), French statesman, was born at Nantes, of a
bourgeois family. He studied law, and while still young took to politics,
associating himself with the most advanced movements, writing articles for
the anarchist journal _Le Peuple_, and directing the _Lanterne_ for some
time. From this he passed to the _Petite République_, leaving it to found,
with Jean Jaurès, _L'Humanité_. At the same time he was prominent in the
movement for the formation of labour unions, and at the congress of working
men at Nantes in 1894 he secured the adoption of the labour union idea
against the adherents of Jules Guesde. From that time, Briand became one of
the leaders of the French Socialist party. In 1902, after several
unsuccessful attempts, he was elected deputy. He declared himself a strong
partisan of the union of the Left in what is known as the _Bloc_, in order
to check the reactionary deputies of the Right. From the beginning of his
career in the chamber of deputies, Briand was occupied with the question of
the separation of church and state. He was appointed reporter of the
commission charged with the preparation of the law, and his masterly report
at once marked him out as one of the coming leaders. He succeeded in
carrying his project through with but slight modifications, and without
dividing the parties upon whose support he relied. He was the principal
author of the law of separation, but, not content with preparing it, he
wished to apply it as well, especially as the existing Rouvier [v.04
p.0516] ministry allowed disturbances to occur during the taking of
inventories of church property, a clause of the law for which Briand was
not responsible. Consequently he accepted the portfolio of public
instruction and worship in the Sarrien ministry (1906). So far as the
chamber was concerned his success was complete. But the acceptance of a
portfolio in a bourgeois ministry led to his exclusion from the Unified
Socialist party (March 1906). As opposed to Jaurès, he contended that the
Socialists should co-operate actively with the Radicals in all matters of
reform, and not stand aloof to await the complete fulfilment of their
ideals.

BRIANZA, a district of Lombardy, Italy, forming the south part of the
province of Como, between the two southern arms of the lake of that name.
It is thickly populated and remarkable for its fertility; and being hilly
is a favourite summer resort of the Milanese.

BRIARE, a town of north-central France in the department of Loiret on the
right bank of the Loire, 45½ m. S.E. of Orléans on the railway to Nevers.
Pop. (1906) 4613. Briare, the _Brivodorum_ of the Romans, is situated at
the extremity of the Canal of Briare, which unites the Loire and its
lateral canal with the Loing and so with the Seine. The canal of Briare was
constructed from 1605 to 1642 and is about 36 m. long. The industries
include the manufacture of fine pottery, and of so-called porcelain buttons
made of felspar and milk by a special process; its inventor, Bapterosses,
has a bust in the town. The canal traffic is in wood, iron, coal, building
materials, &c. A modern hospital and church, and the hôtel de ville
installed in an old moated château, are the chief buildings. The lateral
canal of the Loire crosses the Loire near Briare by a fine canal-bridge 720
yds. in length.

BRIAREUS, or AEGAEON, in Greek mythology, one of the three hundred-armed,
fifty-headed Hecatoncheires, brother of Cottus and Gyges (or Gyes).
According to Homer (_Iliad_ i. 403) he was called Aegaeon by men, and
Briareus by the gods. He was the son of Poseidon (or Uranus) and Gaea. The
legends regarding him and his brothers are various and somewhat
contradictory. According to the most widely spread myth, Briareus and his
brothers were called by Zeus to his assistance when the Titans were making
war upon Olympus. The gigantic enemies were defeated and consigned to
Tartarus, at the gates of which the three brothers were placed (Hesiod,
_Theog._ 624, 639, 714). Other accounts make Briareus one of the assailants
of Olympus, who, after his defeat, was buried under Mount Aetna
(Callimachus, _Hymn to Delos_, 141). Homer mentions him as assisting Zeus
when the other Olympian deities were plotting against the king of gods and
men (_Iliad_ i. 398). Another tradition makes him a giant of the sea, ruler
of the fabulous Aegaea in Euboea, an enemy of Poseidon and the inventor of
warships (Schol. on Apoll. Rhod. i. 1165). It would be difficult to
determine exactly what natural phenomena are symbolized by the
Hecatoncheires. They may represent the gigantic forces of nature which
appear in earthquakes and other convulsions, or the multitudinous motion of
the sea waves (Mayer, _Die Giganten und Titanen_, 1887).

BRIBERY (from the O. Fr. _briberie_, begging or vagrancy, _bribe_, Mid.
Lat. _briba_, signifying a piece of bread given to beggars; the Eng.
"bribe" has passed through the meanings of alms, blackmail and extortion,
to gifts received or given in order to influence corruptly). The public
offence of bribery may be defined as the offering or giving of payment in
some shape or form that it may be a motive in the performance of functions
for which the proper motive ought to be a conscientious sense of duty. When
this is superseded by the sordid impulses created by the bribe, a person is
said to be corrupted, and thus corruption is a term sometimes held
equivalent to bribery. The offence may be divided into two great
classes--the one where a person invested with power is induced by payment
to use it unjustly; the other, where power is obtained by purchasing the
suffrages of those who can impart it. It is a natural propensity, removable
only by civilization or some powerful counteracting influence, to feel that
every element of power is to be employed as much as possible for the
owner's own behoof, and that its benefits should be conferred not on those
who best deserve them, but on those who will pay most for them. Hence
judicial corruption is an inveterate vice of imperfect civilization. There
is, perhaps no other crime on which the force of law, if unaided by public
opinion and morals, can have so little influence; for in other crimes, such
as violence or fraud, there is generally some person immediately injured by
the act, who can give his aid in the detection of the offender, but in the
perpetration of the offence of bribery all the immediate parties obtain
what they desire, and are satisfied.

The purification of the bench from judicial bribery has been gradual in
most of the European countries. In France it received an impulse in the
16th century from the high-minded chancellor, Michel de L'Hôpital. In
England judicial corruption has been a crime of remarkable rarity. Indeed,
with the exception of a statute of 1384 (repealed by the Statute Law
Revision Act 1881) there has been no legislation relating to judicial
bribery. The earliest recorded case was that of Sir William Thorpe, who in
1351 was fined and removed from office for accepting bribes. Other
celebrated cases were those of Michael de la Pole, chancellor of England,
in 1387; Lord Chancellor Bacon in 1621; Lionel Cranfield, earl of
Middlesex, in 1624; and Sir Thomas Parker, 1st earl of Macclesfield, in
1725. In Scotland for some years after the Revolution the bench was not
without a suspicion of interested partiality; but since the beginning of
the 19th century, at least, there has been in all parts of the empire a
perfect reliance on its purity. The same may be said of the higher class of
ministerial officers. There is no doubt that in the period from the
Revolution to the end of Queen Anne's reign, when a speaker of the House of
Commons was expelled for bribery, and the great Marlborough could not clear
his character from pecuniary dishonesty, there was much corruption in the
highest official quarters. The level of the offence of official bribery has
gradually descended, until it has become an extremely rare thing for the
humbler officers connected with the revenue to be charged with it. It has
had a more lingering existence with those who, because their power is more
of a constitutional than an official character, have been deemed less
responsible to the public. During Walpole's administration there is no
doubt that members of parliament were paid in cash for votes; and the
memorable saying, that every man has his price, has been preserved as a
characteristic indication of his method of government. One of the forms in
which administrative corruption is most difficult of eradication is the
appointment to office. It is sometimes maintained that the purity which
characterizes the administration of justice is here unattainable, because
in giving a judgment there is but one form in which it can be justly given,
but when an office has to be filled many people may be equally fitted for
it, and personal motives must influence a choice. It very rarely happens,
however, that direct bribery is supposed to influence such appointments. It
does not appear that bribery was conspicuous in England until, in the early
part of the 18th century, constituencies had thrown off the feudal
dependence which lingered among them; and, indeed, it is often said, that
bribery is essentially the defect of a free people, since it is the sale of
that which is taken from others without payment.

In English law bribery of a privy councillor or a juryman (see EMBRACERY)
is punishable as a misdemeanour, as is the taking of a bribe by any
judicial or ministerial officer. The buying and selling of public offices
is also regarded at common law as a form of bribery. By the Customs
Consolidation Act 1876, any officer in the customs service is liable to
instant dismissal and a penalty of £500 for taking a bribe, and any person
offering or promising a bribe or reward to an officer to neglect his duty
or conceal or connive at any act by which the customs may be evaded shall
forfeit the sum of £200. Under the Inland Revenue Regulations Act 1890, the
bribery of commissioners, collectors, officers or other persons employed in
relation to the Inland Revenue involves a fine of £500. The Merchant
Shipping Act 1894, ss. 112 and 398, makes provision for certain offences in
the nature of bribery. Bribery is, by the Extradition Act 1906, [v.04
p.0517] an extraditable offence. Administrative corruption was dealt with
in the Public Bodies' Corrupt Practices Act 1889. The public bodies
concerned are county councils, town or borough councils, boards,
commissioners, select vestries and other bodies having local government,
public health or poor law powers, and having for those purposes to
administer rates raised under public general acts. The giving or receiving,
promising, offering, soliciting or agreeing to receive any gift, fee, loan
or advantage by any person as an inducement for any act or forbearance by a
member, officer or servant of a public body in regard to the affairs of
that body is made a misdemeanour in England and Ireland and a crime and
offence in Scotland. Prosecution under the act requires the consent of the
attorney or solicitor-general in England or Ireland and of the lord
advocate in Scotland. Conviction renders liable to imprisonment with or
without hard labour for a term not exceeding two years, and to a fine not
exceeding £500, in addition to or in lieu of imprisonment. The offender may
also be ordered to pay to the public body concerned any bribe received by
him; he may be adjudged incapable for seven years of holding public office,
_i.e._ the position of member, officer or servant of a public body; and if
already an officer or servant, besides forfeiting his place, he is liable
at the discretion of the court to forfeit his right to compensation or
pension. On a second conviction he may be adjudged forever incapable of
holding public office, and for seven years incapable of being registered or
of voting as a parliamentary elector, or as an elector of members of a
public body. An offence under the act may be prosecuted and punished under
any other act applicable thereto, or at common law; but no person is to be
punished twice for the same offence. Bribery at political elections was at
common law punishable by indictment or information, but numerous statutes
have been passed dealing with it as a "corrupt practice." In this sense,
the word is elastic in meaning and may embrace any method of corruptly
influencing another for the purpose of securing his vote (see CORRUPT
PRACTICES). Bribery at elections of fellows, scholars, officers and other
persons in colleges, cathedral and collegiate churches, hospitals and other
societies was prohibited in 1588-1589 by statute (31 Eliz. c. 6). If a
member receives any money, fee, reward or other profit for giving his vote
in favour of any candidate, he forfeits his own place; if for any such
consideration he resigns to make room for a candidate, he forfeits double
the amount of the bribe, and the candidate by or on whose behalf a bribe is
given or promised is incapable of being elected on that occasion. The act
is to be read at every election of fellows, &c., under a penalty of £40 in
case of default. By the same act any person for corrupt consideration
presenting, instituting or inducting to an ecclesiastical benefice or
dignity forfeits two years' value of the benefice or dignity; the corrupt
presentation is void, and the right to present lapses for that turn to the
crown, and the corrupt presentee is disabled from thereafter holding the
same benefice or dignity; a corrupt institution or induction is void, and
the patron may present. For a corrupt resignation or exchange of a benefice
the giver and taker of a bribe forfeit each double the amount of the bribe.
Any person corruptly procuring the ordaining of ministers or granting of
licenses to preach forfeits £40, and the person so ordained forfeits £10
and for seven years is incapacitated from holding any ecclesiastical
benefice or promotion.

In the United States the offence of bribery is very severely dealt with. In
many states, bribery or the attempt to bribe is made a felony, and is
punishable with varying terms of imprisonment, in some jurisdictions it may
be with a period not exceeding ten years. The offence of bribery at
elections is dealt with on much the same lines as in England, voiding the
election and disqualifying the offender from holding any office.

Bribery may also take the form of a secret commission (_q.v._), a profit
made by an agent, in the course of his employment, without the knowledge of
his principal.

BRIC À BRAC (a French word, formed by a kind of onomatopoeia, meaning a
heterogeneous collection of odds and ends; cf. _de bric et de broc_,
corresponding to our "by hook or by crook"; or by reduplication from
_brack_, refuse), objects of "virtu," a collection of old furniture, china,
plate and curiosities.

BRICK (derived according to some etymologists from the Teutonic _bricke_, a
disk or plate; but more authoritatively, through the French _brique_,
originally a "broken piece," applied especially to bread, and so to clay,
from the Teutonic _brikan_, to break), a kind of artificial stone generally
made of burnt clay, and largely used as a building material.

_History_.--The art of making bricks dates from very early times, and was
practised by all the civilized nations of antiquity. The earliest burnt
bricks known are those found on the sites of the ancient cities of
Babylonia, and it seems probable that the method of making strong and
durable bricks, by burning blocks of dried clay, was discovered in this
corner of Asia. We know at least that well-burnt bricks were made by the
Babylonians more than 6000 years ago, and that they were extensively used
in the time of Sargon of Akkad (c. 3800 B.C.). The site of the ancient city
of Babylon is still marked by huge mounds of bricks, the ruins of its great
walls, towers and palaces, although it has been the custom for centuries to
carry away from these heaps the bricks required for the building of the
modern towns in the surrounding country. The Babylonians and Assyrians
attained to a high degree of proficiency in brickmaking, notably in the
manufacture of bricks having a coating of coloured glaze or enamel, which
they largely used for wall decoration. The Chinese claim great antiquity
for their clay industries, but it is not improbable that the knowledge of
brickmaking travelled eastwards from Babylonia across the whole of Asia. It
is believed that the art of making glazed bricks, so highly developed
afterwards by the Chinese, found its way across Asia from the west, through
Persia and northern India, to China. The great wall of China was
constructed partly of brick, both burnt and unburnt; but this was built at
a comparatively late period (c. 210 B.C.), and there is nothing to show
that the Chinese had any knowledge of burnt bricks when the art flourished
in Babylonia.

Brickmaking formed the chief occupation of the Israelites during their
bondage in Egypt, but in this case the bricks were probably sun-dried only,
and not burnt. These bricks were made of a mixture of clay and chopped
straw or reeds, worked into a stiff paste with water. The clay was the
river mud from the banks of the Nile, and as this had not sufficient
cohesion in itself, the chopped straw (or reeds) was added as a binding
material. The addition of such substances increases the plasticity of wet
clay, especially if the mixture is allowed to stand for some days before
use; so that the action of the chopped straw was twofold; a fact possibly
known to the Egyptians. These sun-dried bricks, or "adobes," are still
made, as of old, on the banks of the Nile by the following method:--A
shallow pit or bed is prepared, into which are thrown the mud, chopped
straw and water in suitable proportions, and the whole mass is tramped on
until it is thoroughly mixed and of the proper consistence. This mixture is
removed in lumps and shaped into bricks, in moulds or by hand, the bricks
being simply sun-dried.

Pliny mentions that three kinds of bricks were made by the Greeks, but
there is no indication that they were used to any great extent, and
probably the walls of Athens on the side towards Mount Hymettus were the
most important brick-structures in ancient Greece. The Romans became
masters of the brickmaker's art, though they probably acquired much of
their knowledge in the East, during their occupation of Egypt and Greece.
In any case they revived and extended the manufacture of bricks about the
beginning of the Christian era; exercising great care in the selection and
preparation of their clay, and introducing the method of burning bricks in
kilns. They carried their knowledge and their methods throughout western
Europe, and there is abundant evidence that they made bricks extensively in
Germany and in Britain.

Although brickmaking was thus introduced into Britain nearly 2000 years
ago, the art seems to have been lost when the Romans withdrew from the
country, and it is doubtful whether any burnt bricks were made in England
from that time until the 13th century. Such bricks as were used during this
long [v.04 p.0518] period were generally taken from the remains of Roman
buildings, as at Colchester and St Albans Abbey. One of the earliest
existing brick buildings, erected after the revival of brickmaking in
England, is Little Wenham Hall, in Suffolk, built about A.D. 1210; but it
was not until the 15th century that bricks came into general use again, and
then only for important edifices. During the reign of Henry VIII.
brickmaking was brought to great perfection, probably by workmen brought
from Flanders, and the older portions of St James's Palace and Hampton
Court Palace remain to testify to the skill then attained. In the 16th
century bricks were increasingly used, but down to the Great Fire of
London, in 1666, the smaller buildings, shops and dwelling-houses, were
constructed of timber framework filled in with lath and plaster. In the
rebuilding of London after the fire, bricks were largely used, and from the
end of the 17th century to the present day they have been almost
exclusively used in all ordinary buildings throughout the country, except
in those districts where building stone is plentiful and good brick-clay is
not readily procurable. The bricks made in England before 1625 were of many
sizes, there being no recognized standard; but in that year the sizes were
regulated by statute, and the present standard size was adopted, viz. 9 x
4½ x 3 in. In 1784 a tax was levied on bricks, which was not repealed until
1850. The tax averaged about 4s. 7d. per thousand on ordinary bricks, and
special bricks were still more heavily taxed.

The first brick buildings in America were erected on Manhattan Island in
the year 1633 by a governor of the Dutch West India Company. These bricks
were made in Holland, where the industry had long reached great excellence;
and for many years bricks were imported into America from Holland and from
England. In America burnt bricks were first made at New Haven about 1650,
and the manufacture slowly spread through the New England states; but for
many years the home-made article was inferior to that imported from Europe.

The Dutch and the Germans were the great brickmakers of Europe during the
middle ages, although the Italians, from the 14th to the 15th century,
revived and developed the art of decorative brick-work or terra-cotta, and
discovered the method of applying coloured enamels to these materials.
Under the Della Robbias, in the 15th century, some of the finest work of
this class that the world has seen was executed, but it can scarcely be
included under brickwork.

_Brick Clays_.--All clays are the result of the denudation and
decomposition of felspathic and siliceous rocks, and consist of the fine
insoluble particles which have been carried in suspension in water and
deposited in geologic basins according to their specific gravity and degree
of fineness (see CLAY). These deposits have been formed in all geologic
epochs from the "Recent" to the "Cambrian," and they vary in hardness from
the soft and plastic "alluvial" clays to the hard and rock-like shales and
slates of the older formations. The alluvial and drift clays (which were
alone used for brickmaking until modern times) are found near the surface,
are readily worked and require little preparation, whereas the older
sedimentary deposits are often difficult to work and necessitate the use of
heavy machinery. These older shales, or rocky clays, may be brought into
plastic condition by long weathering (_i.e._ by exposure to rain, frost and
sun) or by crushing and grinding in water, and they then resemble ordinary
alluvial clays in every respect.

The clays or earths from which burnt bricks are made may be divided into
two principal types, according to chemical composition: (1) Clays or shales
containing only a small percentage of carbonate of lime and consisting
chiefly of hydrated aluminium silicates (the "true clay substance") with
more or less sand, undecomposed grains of felspar, and oxide or carbonate
of iron; these clays usually burn to a buff, salmon or red colour; (2)
Clays containing a considerable percentage of carbonate of lime in addition
to the substances above mentioned. These latter clay deposits are known as
"marls,"[1] and may contain as much as 40% of chalk. They burn to a
sulphur-yellow colour which is quite distinctive.

Brick clays of class (1) are very widely distributed, and have a more
extensive geological range than the marls, which are found in connexion
with chalk or limestone formations only. These ordinary brick clays vary
considerably in composition, and many clays, as they are found in nature,
are unsuitable for brickmaking without the addition of some other kind of
clay or sand. The strongest brick clays, _i.e._ those possessing the
greatest plasticity and tensile strength, are usually those which contain
the highest percentage of the hydrated aluminium silicates, although the
exact relation of plasticity to chemical composition has not yet been
determined. This statement cannot be applied indiscriminately to all clays,
but may be taken as fairly applicable to clays of one general type (see
CLAY). All clays contain more or less free silica in the form of sand, and
usually a small percentage of undecomposed felspar. The most important
ingredient, after the clay-substance and the sand, is oxide of iron; for
the colour, and, to a less extent, the hardness and durability of the burnt
bricks depend on its presence. The amount of oxide of iron in these clays
varies from about 2 to 10%, and the colour of the bricks varies accordingly
from light buff to chocolate; although the colour developed by a given
percentage of oxide of iron is influenced by the other substances present
and also by the method of firing. A clay containing from 5 to 8% of oxide
of iron will, under ordinary conditions of firing, produce a red brick; but
if the clay contains 3 to 4% of alkalis, or the brick is fired too hard,
the colour will be darker and more purple. The actions of the alkalis and
of increased temperature are probably closely related, for in either case
the clay is brought nearer to its fusion point, and ferruginous clays
generally become darker in colour as they approach to fusion. Alumina acts
in the opposite direction, an excess of this compound tending to make the
colour lighter and brighter. It is impossible to give a typical composition
for such clays, as the percentages of the different constituents vary
through such wide ranges. The clay substance may vary from 15 to 80%, the
free silica or sand from 5 to 80%, the oxide of iron from 1 to 10%, the
carbonates of lime and magnesia together, from 1 to 5%, and the alkalis
from 1 to 4%. Organic matter is always present, and other impurities which
frequently occur are the sulphates of lime and magnesia, the chlorides and
nitrates of soda and potash, and iron-pyrites. The presence of organic
matter gives the wet clay a greater plasticity, probably because it forms a
kind of mucilage which adds a certain viscosity and adhesiveness to the
natural plasticity of the clay. In some of the coal-measure shales the
amount of organic matter is very considerable, and may render the clay
useless for brickmaking. The other impurities, all of which, except the
pyrites, are soluble in water, are undesirable, as they give rise to
"scum," which produces patchy colour and pitted faces on the bricks. The
commonest soluble impurity is calcium sulphate, which produces a whitish
scum on the face of the brick in drying, and as the scum becomes
permanently fixed in burning, such bricks are of little use except for
common work. This question of "scumming" is very important to the maker of
high-class facing and moulded bricks, and where a clay containing calcium
sulphate must be used, a certain percentage of barium carbonate is nowadays
added to the wet clay. By this means the calcium sulphate is converted into
calcium carbonate which is insoluble in water, so that it remains
distributed throughout the mass of the brick instead of being deposited on
the surface. The presence of magnesium salts is also very objectionable, as
these generally remain in the burnt brick as magnesium sulphate, which
gives rise to an efflorescence of fine white crystals after the bricks are
built into position. Clays which are strong or plastic are known as "fat"
clays, and they always contain a high percentage of true "clay substance,"
and, consequently, a low percentage of sand. Such clays take up a
considerable amount of water in "tempering"; they dry slowly, shrink
greatly, and so become liable to lose their shape and develop cracks in
drying and firing. "Fat" clays are greatly improved by the addition of
coarse sharp sand, [v.04 p.0519] which reduces the time of drying and the
shrinkage, and makes the brick more rigid during the firing. Coarse sand,
unlike clay-substance, is practically unaffected during the drying and
firing, and is a desirable if not a necessary ingredient of all brick
clays. The best brick-clays feel gritty between the fingers; they should,
of course, be free from pebbles, sufficiently plastic to be moulded into
shape and strong enough when dry to be safely handled. All clays are
greatly improved by being turned over and exposed to the weather, or by
standing for some months in a wet condition. This "weathering" and "ageing"
of clay is particularly important where bricks are made from tempered clay,
_i.e._ clay in the wet or plastic state; where bricks are made from shale,
in the semi-plastic condition, weathering is still of importance.

The lime clays or "marls" of class (2), which contain essentially a high
percentage of chalk or limestone, are not so widely distributed as the
ordinary brick-clays, and in England the natural deposits of these clays
have been largely exhausted. A very fine chalk-clay, or "malm" as it was
locally called, was formerly obtained from the alluvium in the vicinity of
London; but the available supply of this has been used up, and at the
present time an artificial "malm" is prepared by mixing an ordinary
brick-clay with ground chalk. For the best London facing-bricks the clay
and chalk are mixed in water. The chalk is ground on grinding-pans, and the
clay is mixed with water and worked about until the mixture has the
consistence of cream. The mixture of these "pulps" is run through a grating
or coarse sieve on to a drying-kiln or "bed," where it is allowed to stand
until stiff enough to walk on. A layer of fine ashes is then spread over
the clay, and the mass is turned over and mixed by spade, and tempered by
the addition of water. In other districts, where clays containing limestone
are used, the marl is mixed with water on a wash-pan and the resulting
creamy fluid passed through coarse sieves on to a drying-bed. If necessary,
coarse sand is added to the clay in the wash-pan, and such addition is
often advisable because the washed clays are generally very fine in grain.
Another method of treating these marls, when they are in the plastic
condition, is to squeeze them by machinery through iron gratings, which
arrest and remove the pebbles. In other cases the marl is passed through a
grinding-mill having a solid bottom and heavy iron rollers, by which means
the limestone pebbles are crushed sufficiently and mixed through the whole
mass. The removal of limestone pebbles from the clay is of great
importance, as during the firing they would be converted into quicklime,
which has a tendency to shatter the brick on exposure to the weather. As
before stated, these marls (which usually contain from 15 to 30% of calcium
carbonate) burn to a yellow colour which is quite distinctive, although in
some cases, where the percentage of limestone is very high, over 40%, the
colour is grey or a very pale buff. The action of lime in bleaching the
ferric oxide and producing a yellow instead of a red brick, has not been
thoroughly investigated, but it seems probable that some compound is
produced, between the lime and the oxide of iron, or between these two
oxides and the free silica, entirely different from that produced by oxide
of iron in the absence of lime. Such marls require a harder fire than the
ordinary brick-clays in order to bring about the reaction between the lime
and the other ingredients. Magnesia may replace lime to some extent in such
marls, but the firing temperature must be higher when magnesia is present.
Marls usually contract very little, if at all, in the burning, and
generally produce a strong, square brick of fine texture and good colour.
When under-fired, marl bricks are very liable to disintegrate under the
action of the weather, and great care must be exercised in burning them at
a sufficiently high temperature.

_Brickmaking_.--Bricks made of tempered clay may be made by hand or by
machine, and the machines may be worked by hand or by mechanical power.
Bricks made of semi-plastic clay (_i.e._ ground clay or shale sufficiently
damp to adhere under pressure) are generally machine-made throughout. The
method of making bricks by hand is the same, with slight variation, the
world over. The tempered clay is pressed by hand into a wooden or metal
mould or four-sided case (without top or bottom) which is of the desired
shape and size, allowance being made for the shrinkage of the brick in
drying and firing. The moulder stands at the bench or table, dips the mould
in water, or water and then sand, to prevent the clay from sticking, takes
a rudely shaped piece of clay from an assistant, and dashes this into the
mould which rests on the moulding bench. He then presses the clay into the
corners of the mould with his fingers, scrapes off any surplus clay and
levels the top by means of a strip of wood called a "strike," and then
turns the brick out of the mould on to a board, to be carried away by
another assistant to the drying-ground. The mould may be placed on a
special piece of wood, called the stock-board, provided with an elevated
tongue of wood in the centre, which produces the hollow or "frog" in the
bottom of the brick.

Machine-made bricks may be divided into two kinds, plastic and
semi-plastic, although the same type of machine is often used for both
kinds.

The machine-made plastic bricks are made of tempered clay, but generally
the tempering and working of the clay are effected by the use of machinery,
especially when the harder clays and shales are used. The machines used in
the preparation of such clays are grinding-mills and pug-mills. The
grinding-mills are either a series of rollers with graduated spaces
between, through which the clay or shale is passed, or are of the ordinary
"mortar pan" type, having a solid or perforated iron bottom on which the
clay or shale is crushed by heavy rollers. Shales are sometimes passed
through a grinding-mill before they are exposed to the action of the
weather, as the disintegration of the hard lumps of shale greatly
accelerates the "weathering." In the case of ordinary brick-clay, in the
plastic condition, grinding-mills are only used when pebbles more than a
quarter of an inch in diameter are present, as otherwise the clay may be
passed directly through the pug-mill, a process which may be repeated if
necessary. The pug-mill consists of a box or trough having a feed hole at
one end and a delivery hole or nose at the other end, and provided with a
central shaft which carries knives and cutters so arranged that when the
shaft revolves they cut and knead the clay, and at the same time force it
towards and through the delivery nose. The cross section of this nose of
the pug-mill is approximately the same as that of the required brick (9 in.
× 4½ in. plus contraction, for ordinary bricks), so that the pug delivers a
solid or continuous mass of clay from which bricks may be made by merely
making a series of square cuts at the proper distances apart. In practice,
the clay is pushed from the pug along a smooth iron plate, which is
provided with a wire cutting frame having a number of tightly stretched
wires placed at certain distances apart, arranged so that they can be
brought down upon, and through, the clay, and so many bricks cut off at
intervals. The frame is sometimes in the form of a skeleton cylinder, the
wires being arranged radially (or the wires may be replaced by metal
disks); but in all cases bricks thus made are known as "wire-cuts." In
order to obtain a better-shaped and more compact brick, these wire-cuts may
be placed under a brick press and there squeezed into iron moulds under
great pressure. These two processes are now generally performed by one
machine, consisting of pug-mill and brick press combined. The pug delivers
the clay, downwards, into the mould; the proper amount of clay is cut off;
and the mould is made to travel into position under the ram of the press,
which squeezes the clay into a solid mass.

There are many forms of brick press, a few for hand power, but the most
adapted for belt-driving; although in recent years hydraulic presses have
come more and more into use, especially in Germany and America. The
essential parts of a brick press are: (1) a box or frame in which the clay
is moulded; (2) a plunger or die carried on the end of a ram, which gives
the necessary pressure; (3) an arrangement for pushing the pressed brick
out of the moulding box. Such presses are generally made of iron
throughout, although other metals are used, occasionally, for the moulds
and dies. The greatest variations found in brick presses are in the means
adopted for actuating the ram; and many ingenious mechanical devices have
been applied to this end, each claiming some particular advantage over its
predecessors. In many recent presses, especially where semi-plastic clay is
used, the brick is pressed simultaneously from top and bottom, a second
ram, working upwards from beneath, giving the additional pressure.

Although the best bricks are still pressed from tempered or plastic clay,
there has recently been a great development in the manufacture of
semi-plastic or dust-made bricks, especially in those districts where
shales are used for brickmaking. These semi-plastic bricks are stamped out
of ground shale that has been sufficiently moistened with water to enable
it to bind together. The hard-clay, or shale, is crushed under heavy
rollers in an iron grinding-pan having a perforated bottom through which
the crushed clay passes, when sufficiently fine, into a small compartment
underneath. This clay powder is then delivered, by an elevator, into a
sieve or screen, which retains the coarser particles for regrinding. Sets
of rollers may also be used for crushing shales that are only moderately
hard, the ground material being sifted as before. The material, as fed
[v.04 p.0520] into the mould of the press, is a coarse, damp powder which
becomes adhesive under pressure, producing a so-called "semi-plastic"
brick. The presses used are similar to those employed for plastic clay, but
they are generally more strongly and heavily built, and are capable of
applying a greater pressure.

The semi-plastic method has many advantages where shales are used, although
the bricks are not as strong nor as perfect as the best "plastic" bricks.
The method, however, enables the brickmaker to make use of certain kinds of
clay-rock, or shale, that would be impracticable for plastic bricks; and
the weathering, tempering and "ageing" may be largely or entirely dispensed
with. The plant required is heavier and more costly, but the brickyard
becomes more compact, and the processes are simpler than with the "plastic"
method.

The drying of bricks, which was formerly done in the open, is now, in most
cases, conducted in a special shed heated by flues along which the heated
gases from the kilns pass on their way to the chimney. It is important that
the atmosphere of the drying-shed should be fairly dry, to which end
suitable means of ventilation must be arranged (by fans or otherwise). If
the atmosphere is too moist the surface of the brick remains damp for a
considerable time, and the moisture from the interior passes to the surface
as water, carrying with it the soluble salts, which are deposited on the
surface as the water slowly evaporates. This deposit produces the "scum"
already referred to. When the drying is done in a dry atmosphere the
surface quickly dries and hardens, and the moisture from the interior
passes to the surface as vapour, the soluble salts being left distributed
through the whole mass, and consequently no "scum" is produced. Plastic
bricks take much longer to dry than semi-plastic; they shrink more and have
a greater tendency to warp or twist.

The burning or firing of bricks is the most important factor in their
production; for their strength and durability depend very largely on the
character and degree of the firing to which they have been subjected. The
action of the heat brings about certain chemical decompositions and
re-combinations which entirely alter the physical character of the dry
clay. It is important, therefore, that the firing should be carefully
conducted and that it should be under proper control. For ordinary bricks
the firing atmosphere should be oxidizing, and the finishing temperature
should be adjusted to the nature of the clay, the object being to produce a
hard strong brick, of good shape, that will not be too porous and will
withstand the action of frost. The finishing temperature ranges from 900°
C. to 1250° C., the usual temperature being about 1050° C. for ordinary
bricks. As before mentioned, lime-clays require a higher firing temperature
(usually about 1150° C. to 1200° C.) in order to bring the lime into
chemical combination with the other substances present.

It is evident that the best method of firing bricks is to place them in
permanent kilns, but although such kilns were used by the Romans some 2000
years ago, the older method of firing in "clamps" is still employed in the
smaller brickfields, in every country where bricks are made. These clamps
are formed by arranging the unfired bricks in a series of rows or walls,
placed fairly closely together, so as to form a rectangular stack. A
certain number of channels, or firemouths, are formed in the bottom of the
clamp; and fine coal is spread in horizontal layers between the bricks
during the building up of the stack. Fires are kindled in the fire-mouths,
and the clamp is allowed to go on burning until the fuel is consumed
throughout. The clamp is then allowed to cool, after which it is taken
down, and the bricks sorted; those that are under-fired being built up
again in the next clamp for refiring. Sometimes the clamp takes the form of
a temporary kiln, the outside being built of burnt bricks which are
plastered over with clay, and the fire-mouths being larger and more
carefully formed. There are many other local modifications in the manner of
building up the clamps, all with the object of producing a large percentage
of well-fired bricks. Clamp-firing is slow, and also uneconomical, because
irregular and not sufficiently under control; and it is now only employed
where bricks are made on a small scale.

Brick-kilns are of many forms, but they can all be grouped under two main
types--Intermittent kilns and Continuous kilns. The intermittent kiln is
usually circular in plan, being in the form of a vertical cylinder with a
domed top. It consists of a single firing-chamber in which the unfired
bricks are placed, and in the walls of which are contrived a number of
fire-mouths where wood or coal is burned. In the older forms known as
_up-draught_ kilns, the products of combustion pass from the fire-mouth,
through flues, into the bottom of the firing-chamber, and thence directly
upwards and out at the top. The modern plan is to introduce the products of
combustion near the top, or crown, of the kiln, and to draw them downwards
through holes in the bottom which lead to flues connected with an
independent chimney. These _down-draught_ kilns have short chimneys or
"bags" built round the inside wall in connexion with the fire-mouths, which
conduct the flames to the upper part of the firing-chamber, where they are
reverberated and passed down through the bricks in obedience to the pull of
the chimney. The "bags" may be joined together, forming an inner circular
wall entirely round the firing-chamber, except at the doorway; and a number
of kilns may be built in a row or group having their bottom flues connected
with the same tall chimney. Down-draught kilns usually give a more regular
fire and a higher percentage of well-fired bricks; and they are more
economical in fuel consumption than up-draught kilns, while the hot gases,
as they pass from the kiln, may be utilized for drying purposes, being
conducted through flues under the floor of the drying-shed, on their way to
the chimney. The method of using one tall chimney to work a group of
down-draught kilns naturally led to the invention of the "continuous" kiln,
which is really made up of a number of separate kilns or firing-chambers,
built in series and connected up to the main flue of the chimney in such a
manner that the products of combustion from one kiln may be made to pass
through a number of other kilns before entering the flue. The earliest form
of continuous kiln was invented by Friedrich Hoffman, and all kilns of this
type are built on the Hoffman principle, although there are a great number
of modifications of the original Hoffman construction. The great principle
of "continuous" firing is the utilization of the waste heat from one kiln
or section of a kiln in heating up another kiln or section, direct firing
being applied only to finish the burning. In practice a number of kilns or
firing-chambers, usually rectangular in plan, are built side by side in two
parallel lines, which are connected at the ends by other kilns so as to
make a complete circuit. The original form of the complete series was
elliptical in plan, but the tendency in recent years has been to flatten
the sides of the ellipse and bring them together, thus giving two parallel
rows joined at the ends by a chamber or passage at right angles. Coal or
gas is burnt in the chamber or section that is being fired-up, the air
necessary for the combustion being heated on its passage through the kilns
that are cooling down, and the products of combustion, before entering the
chimney flue, are drawn through a number of other kilns or chambers
containing unfired bricks, which are thus gradually heated up by the
otherwise waste-heat from the sections being fired. Continuous kilns
produce a more evenly fired product than the intermittent kilns usually do,
and, of course, at much less cost for fuel. Gas firing is now being
extensively applied to continuous kilns, natural gas in some instances
being used in the United States of America; and the methods of construction
and of firing are carried out with greater care and intelligence, the prime
objects being economy of fuel and perfect control of firing. Pyrometers are
coming into use for the control of the firing temperature, with the result
that a constant and trustworthy product is turned put. The introduction of
machinery greatly helped the brickmaking industry in opening up new sources
of supply of raw material in the shales and hardened clays of the
sedimentary deposits of the older geologic formations, and, with the
extended use of continuous firing plants, it has led to the establishment
of large concerns where everything is co-ordinated for the production of
enormous quantities of bricks at a minimum cost. In the United Kingdom, and
still more in Germany and the United States of America, great improvements
have been made in machinery, firing-plant and organization, so that the
whole manufacture is now being conducted on more scientific lines, to the
great advantage of the industry.

_Blue Brick_ is a very strong vitreous brick of dark, slaty-blue colour,
used in engineering works where great strength or impermeability is
desirable. These bricks are made of clay containing front 7 to 10% of oxide
of iron, and their manufacture is carried out in the ordinary way until the
later stages of the firing process, when they are subjected to the strongly
reducing action of a smoky atmosphere, which is produced by throwing small
bituminous coal upon the fire-mouths and damping down the admission of air.
The smoke thus produced reduces the red ferric oxide to blue-green ferrous
oxide, or to metallic iron, which combines with the silica present to form
a fusible ferrous silicate. This fusible "slag" partly combines with the
other silicates present, and partly fills up the pores, and so produces a
vitreous impermeable layer varying in thickness according to the duration
and character of the smoking, the finishing temperature of the kiln and the
texture of the brick. Particles of carbon penetrate the surface during the
early stages of the smoking, and a small quantity of carbon probably enters
into combination, tending to produce a harder surface and darker colour.

_Floating Bricks_ were first mentioned by Strabo, the Greek geographer, and
afterwards by Pliny as being made at Pitane in the Troad. The secret of
their manufacture was lost for many centuries, but was rediscovered in 1791
by Fabroni, an Italian, who made them from the fossil meal (diatomaceous
earth) found in Tuscany. These bricks are very light, fairly strong, and
being poor conductors of heat, have been employed for the construction of
powder-magazines on board ship, &c.

_Mortar Bricks_ belong to the class of unburnt bricks, and are, strictly
speaking, blocks of artificial stone made in brick moulds. These bricks
have been made for many years by moulding a mixture of sand and slaked lime
and allowing the blocks thus made to harden in the air. This hardening is
brought about partly by evaporation of the water, but chiefly by the
conversion of the calcium hydrate, or slaked lime, into calcium carbonate
by the action of the carbonic acid in the atmosphere. A small proportion of
the lime enters into combination with the silica and water present to form
hydrated calcium silicate, and probably a little hydrated basic carbonate
of lime is also formed, both of which substances are in the nature of
cement. This process of natural hardening by exposure to the air was a very
long one, occupying from six to eighteen months, and many improvements were
introduced during the latter half of the 19th century to improve the
strength of the bricks and to hasten the hardening. [v.04 p.0521] Mixtures
of sand, lime and cement (and of certain ground blast-furnace slags and
lime) were introduced; the moulding was done under hydraulic presses and
the bricks afterwards treated with carbon dioxide under pressure, with or
without the application of mild heat. Some of these mixtures and methods
are still in use, but a new type of mortar brick has come into use during
recent years which has practically superseded the old mortar brick.

_Sand-lime Bricks_.--In the early 'eighties of the 19th century, Dr
Michaelis of Berlin patented a new process for hardening blocks made of a
mixture of sand and lime by treating them with high-pressure steam for a
few hours, and the so-called _sand-lime_ bricks are now made on a very
extensive scale in many countries. There are many differences of detail in
the manufacture, but the general method is in all cases the same. Dry sand
is intimately mixed with about one-tenth of its weight of powdered slaked
lime, the mixture is then slightly moistened with water and afterwards
moulded into bricks under powerful presses, capable of exerting a pressure
of about 60 tons per sq. in. After removal from the press the bricks are
immediately placed in huge steel cylinders usually 60 to 80 ft. long and
about 7 ft. in diameter, and are there subjected to the action of
high-pressure steam (120 lb to 150 lb per sq. in.) for from ten to fifteen
hours. The proportion of slaked lime to sand varies according to the nature
of the lime and the purity and character of the sand, one of lime to ten of
sand being a fair average. The following is an analysis of a typical German
sand-lime brick: silica (SiO_2), 84%; lime (CaO), 7%; alumina and oxide of
iron, 2%; water, magnesia and alkalis, 7%. Under the action of the
high-pressure steam the lime attacks the particles of sand, and a chemical
compound of water, lime and silica is produced which forms a strong bond
between the larger particles of sand. This bond of hydrated calcium
silicate is evidently different from, and of better type than, the filling
of calcium carbonate produced in the mortar-brick, and the sand-lime brick
is consequently much stronger than the ordinary mortar-brick, however the
latter may be made. The sand-lime brick is simple in manufacture, and with
reasonable care is of constant quality. It is usually of a light-grey
colour, but may be stained by the addition of suitable colouring oxides or
pigments unaffected by lime and the conditions of manufacture.

_Strength of Brick._--The following figures indicate the crushing load for
bricks of various types in tons per sq. in.:--

Common hand-made from 0.4 to 0.9
" machine-made " 0.9 " 1.2
London stock " 0.7 " 1.3
Staffordshire blue " 2.8 " 3.3
Sand-lime " 2.9 " 3.4

See also BRICKWORK.

(J. B.*; W. B.*)

[1] The term "marl" has been wrongly applied to many fire-clays. It should
be restricted to natural mixtures of clay and chalk such as those of the
Paris and London basins.

BRICKFIELDER, a term used in Australia for a hot scorching wind blowing
from the interior, where the sandy wastes, bare of vegetation in summer,
are intensely heated by the sun. This hot wind blows strongly, often for
several days at a time, defying all attempts to keep the dust down, and
parching all vegetation. It is in one sense a healthy wind, as, being
exceedingly dry and hot, it destroys many injurious germs of disease. The
northern brickfielder is almost invariably followed by a strong "southerly
buster," cloudy and cool from the ocean. The two winds are due to the same
cause, viz. a cyclonic system over the Australian Bight. These systems
frequently extend inland as a narrow V-shaped depression (the apex
northward), bringing the winds from the north on their eastern sides and
from the south on their western. Hence as the narrow system passes eastward
the wind suddenly changes from north to south, and the thermometer has been
known to fall fifteen degrees in twenty minutes.

BRICKWORK, in building, the term applied to constructions made of bricks.
The tools and implements employed by the bricklayer are:--the trowel for
spreading the mortar; the plumb-rule to keep the work perpendicular, or in
the case of an inclined or battering wall, to a regular batter, for the
plumb-rule may be made to suit any required inclination; the spirit-level
to keep the work horizontal, often used in conjunction with a straight-edge
in order to test a greater length; and the gauge-rod with the brick-courses
marked on it. The quoins or angles are first built up with the aid of the
gauge-rod, and the intermediate work is kept regular by means of the line
and line pins fixed in the joints. The raker, jointer, pointing rule and
Frenchman are used in pointing joints, the pointing staff being held on a
small board called the hawk. For roughly cutting bricks the large trowel is
used; for neater work such as facings, the bolster and club-hammer; the
cold chisel is for general cutting away, and for chases and holes. When
bricks require to be cut, the work is set out with the square, bevel and
compasses. If the brick to be shaped is a hard one it is placed on a
V-shaped cutting block, an incision made where desired with the tin saw,
and after the bolster and club-hammer have removed the portion of the
brick, the scutch, really a small axe, is used to hack off the rough parts.
For cutting soft bricks, such as rubbers and malms, a frame saw with a
blade of soft iron wire is used, and the face is brought to a true surface
on the rubbing stone, a slab of Yorkshire stone.

In ordinary practice a scaffold is carried up with the walls and made to
rest on them. Having built up as high as he can reach from the ground, the
scaffolder erects a scaffold with standards, ledgers and putlogs to carry
the scaffold boards (see SCAFFOLD, SCAFFOLDING). Bricks are carried to the
scaffold on a hod which holds twenty bricks, or they may be hoisted in
baskets or boxes by means of a pulley and fall, or may be raised in larger
numbers by a crane. The mortar is taken up in a hod or hoisted in pails and
deposited on ledged boards about 3 ft. square, placed on the scaffold at
convenient distances apart along the line of work. The bricks are piled on
the scaffold between the mortar boards, leaving a clear way against the
wall for the bricklayers to move along. The workman, beginning at the
extreme left of his section, or at a quoin, advances to the right,
carefully keeping to his line and frequently testing his work with the
plumb-rule, spirit-level and straight-edge, until he reaches another angle,
or the end of his section. The pointing is sometimes finished off as the
work proceeds, but in other cases the joints are left open until the
completion, when the work is pointed down, perhaps in a different mortar.
When the wall has reached a height from the scaffold beyond which the
workman cannot conveniently reach, the scaffolding is raised and the work
continued in this manner from the new level.

[Illustration: FIG. 1.]

It is most important that the brickwork be kept perfectly plumb, and that
every course be perfectly horizontal or level, both longitudinally and
transversely. Strictest attention should be paid to the levelling of the
lowest course of footings of a wall, for any irregularity will necessitate
the inequality being made up with mortar in the courses above, thus
inducing a liability for the wall to settle unequally, and so perpetuate
the infirmity. To save the trouble of keeping the plumb-rule and level
constantly in his hands and yet ensure correct work, the bricklayer, on
clearing the footings of a wall, builds up six or eight courses of bricks
at the external angles (see fig. 1), which he carefully plumbs and levels
across. These form a gauge for the intervening work, a line being tightly
strained between and fixed with steel pins to each angle at a level with
the top of the next course to be laid, and with this he makes his work
range. If, however, the length between the quoins be great, the line will
of course sag, and it must, therefore, be carefully supported at intervals
to the proper level. Care must be taken to keep the "perpends," or vertical
joints, one immediately over the other. Having been carried up three or
four courses to a level with the guidance of the line which is raised
course by course, the work should be proved with the level and plumb-rule,
particularly with the latter at the quoins and reveals, as well as over the
face. A smart tap with the end of the handle of the trowel will suffice to
make a brick yield what little it may be out of truth, while the work is
green, and not injure it. The work of an efficient craftsman, however, will
need but little adjustment.

For every wall of more than one brick (9 in) thick, two men should be
employed at the same time, one on the outside and the [v.04 p.0522] other
inside; one man cannot do justice from one side to even a 14-in. wall. When
the wall can be approached from one side only, the work is said to be
executed "overhand." In work circular on plan, besides the level and
plumb-rule, a gauge mould or template, or a ranging trammel--a rod working
on a pivot at the centre of the curve, and in length equalling the
radius--must be used for every course, as it is evident that the line and
pins cannot be applied to this in the manner just described.

Bricks should not be merely _laid_, but each should be placed frog upwards,
and rubbed and pressed firmly down in such a manner as to secure absolute
adhesion, and force the mortar into joints. Every brick should be well
wetted before it is laid, especially in hot dry weather, in order to wash
off the dust from its surface, and to obtain more complete adhesion, and
prevent it from absorbing water from the mortar in which it is bedded. The
bricks are wetted either by the bricklayer dipping them in water as he uses
them, or by water being thrown or sprinkled on them as they lie piled on
the scaffold. In bricklaying with quick-setting cements an ample use of
water is of even more importance.

All the walls of a building that are to sustain the same floors and the
same roof, should be carried up simultaneously; in no circumstances should
more be done in one part than can be reached from the same scaffold, until
all the walls are brought up to the same height. Where it is necessary for
any reason to leave a portion of the wall at a certain level while carrying
up the adjoining work the latter should be racked back, i.e. left in steps
as shown in fig. 7, and not carried up vertically with merely the toothing
necessary for the bond.

[Illustration: FIG. 2.--Section of a Hollow Wall.]

Buildings in exposed situations are frequently built with cavity-walls,
consisting of the inside or main walls with an outer skin [Sidenote: Hollow
walls.] usually half a brick thick, separated from the former by a cavity
of 2 or 3 in. (fig. 2). The two walls are tied together at frequent
intervals by iron or stoneware ties, each having a bend or twist in the
centre, which prevents the transmission of water to the inner wall. All
water, therefore, which penetrates the outer wall drops to the base of the
cavity, and trickles out through gratings provided for the purpose a few
inches above the ground level. The base of the cavity should be taken down
a course or two below the level of the damp-proof course. The ties are
placed about 3 ft. apart horizontally, with 12 or 18 in. vertical
intervals; they are about 8 in. long and ¾ in. wide. It is considered
preferable by some architects and builders to place the thicker wall on the
outside. This course, however, allows the main wall to be attacked by the
weather, whereas the former method provides for its protection by a screen
of brickwork. Where door and window frames occur in hollow walls, it is of
the utmost importance that a proper lead or other flashing be built in,
shaped so as to throw off on each side, clear of the frames and main wall,
the water which may penetrate the outer shell. While building the wall it
is very essential to ensure that the cavity and ties be kept clean and free
from rubbish or mortar, and for this purpose a wisp of straw or a narrow
board, is laid on the ties where the bricklayer is working, to catch any
material that may be inadvertently dropped, this protection being raised as
the work proceeds. A hollow wall tends to keep the building dry internally
and the temperature equable, but it has the disadvantage of harbouring
vermin, unless care be taken to ensure their exclusion. The top of the wall
is usually sealed with brickwork to prevent vermin or rubbish finding its
way into the cavity. Air gratings should be introduced here to allow of air
circulating through the cavity; they also facilitate drying out after rain.

Hollow walls are not much used in London for two reasons, the first being
that, owing to the protection from the weather afforded by surrounding
buildings, one of the main reasons for their use is gone, and the other
that the expense is greatly increased, owing to the authorities ignoring
the outer shell and requiring the main wall to be of the full thickness
stipulated in schedule I. of London Building Act 1894. Many English
provincial authorities in determining the thickness of a cavity-wall, take
the outer portion into consideration.

In London and the surrounding counties, brickwork is measured by the _rod_
of 16½ ft. square, 1½ bricks in thickness. A rod of brickwork [Sidenote:
Materials and labour.] gauged four courses to a foot with bricks 8¾ in.
long, 4¼ in. wide, and 2¾ in thick, and joints ¼ in. in thickness, will
require 4356 bricks, and the number will vary as the bricks are above or
below the average size, and as the joints are made thinner or thicker. The
quantity of mortar, also, will evidently be affected by the latter
consideration, but in London it is generally reckoned at 50 cub. ft. for a
¼-in. joint, to 72 cub. ft. for a joint 3/8 in. thick. To these figures
must be added an allowance of about 11 cub. ft. if the bricks are formed
with frogs or hollows. Bricks weigh about 7 lb each; they are bought and
sold by the thousand, which quantity weighs about 62 cwt. The weight of a
rod of brickwork is 13½-15 tons, work in cement mortar being heavier than
that executed in lime. Seven bricks are required to face a sq. ft.; 1 ft.
of reduced brickwork--1½ bricks thick--will require 16 bricks. The number
of bricks laid by a workman in a day of eight hours varies considerably
with the description of work, but on straight walling a man will lay an
average of 500 in a day.

The absorbent properties of bricks vary considerably with the kind of
brick. The ordinary London stock of good quality should [Sidenote:
Varieties of bricks.] not have absorbed, after twenty-four hours' soaking,
more than one-fifth of its bulk. Inferior bricks will absorb as much as a
third. The Romans were great users of bricks, both burnt and sun-dried. At
the decline of the Roman empire, the art of brickmaking fell into disuse,
but after the lapse of some centuries it was revived, and the ancient
architecture of Italy shows many fine examples of brick and terra-cotta
work. The scarcity of stone in the Netherlands led to the development of a
brick architecture, and fine examples of brickwork abound in the Low
Countries. The Romans seem to have introduced brickmaking into England, and
specimens of the large thin bricks, which they used chiefly as a bond for
rubble masonry, may be seen in the many remains of Roman buildings
scattered about that country. During the reigns of the early Tudor kings
the art of brickmaking arrived at great perfection, and some of the finest
known specimens of ornamental brickwork are to be found among the work of
this period. The rebuilding of London after the Great Fire of 1666 gave
considerable impetus to brickmaking, most of the new buildings being of
brick, and a statute was passed regulating the number of bricks in the
thickness of the walls of the several rates of dwelling-houses.

The many names given to the different qualities of bricks in various parts
of Great Britain are most confusing, but the following are those generally
in use:--

_Stocks_, hard, sound, well-burnt bricks, used for all ordinary purposes.

_Hard Stocks,_ sound but over-burnt, used in footings to walls and other
positions where good appearance is not required.

_Shippers_, sound, hard-burnt bricks of imperfect shape. Obtain their name
from being much used as ballast for ships.

_Rubbers_ or _Cutters_, sandy in composition and suitable for cutting with
a wire saw and rubbing to shape on the stone slab.

_Grizzles_, sound and of fair shape, but under-burnt; used for inferior
work, and in cases where they are not liable to be heavily loaded.

_Place-bricks_, under-burnt and defective; used for temporary work.

_Chuffs_, cracked and defective in shape and badly burnt. [v.04 p.0523]
_Burrs_, lumps which have vitrified or run together in the burning; used
for rough walling, garden work, &c.

_Pressed bricks_, moulded under hydraulic pressure, and much used for
facing work. They usually have a deep frog or hollow on one or both
horizontal faces, which reduces the weight of the brick and forms an
excellent key for the mortar.

_Blue bricks_, chiefly made in South Staffordshire and North Wales. They
are used in engineering work, and where great compressional resistance is
needed, as they are vitrified throughout, hard, heavy, impervious and very
durable. Blue bricks of special shape may be had for paving, channelling
and coping.

_Fire-bricks_, withstanding great heat, used in connexion with furnaces.
They should always be laid with fire-clay in place of lime or cement
mortar.

_Glazed bricks_, either salt-glazed or enamelled. The former, brown in
colour, are glazed by throwing salt on the bricks in the kiln. The latter
are dipped into a slip of the required colour before being burnt, and are
used for decorative and sanitary purposes, and where reflected light is
required.

_Moulded bricks_, for cornices, string courses, plinths, labels and
copings. They are made in the different classes to many patterns; and on
account of their greater durability, and the saving of the labour of
cutting, are preferable in many cases to rubbers. For sewer work and
arches, bricks shaped as voussoirs are supplied.

The strength of brickwork varies very considerably according to the kind of
brick used, the position in which it is used, the kind and [Sidenote:
Strength of brickwork.] quality of the lime or cement mortar, and above all
the quality of the workmanship. The results of experiments with short walls
carried out in 1896-1897 by the Royal Institute of British Architects to
determine the average loads per sq. ft. at which crushing took place, may
be briefly summarized as follows: Stock brickwork in lime mortar crushed
under a pressure of 18.63 tons per sq. ft., and in cement mortar under
39.29 tons per sq. ft. Gault brickwork in lime mortar crushed at 31.14
tons, and in cement mortar at 51.34 tons. Fletton brickwork in lime crushed
under a load of 30.68 tons, in cement under 56.25 tons. Leicester red
brickwork in lime mortar crushed at 45.36 tons per sq. ft., in cement
mortar at 83.36 tons. Staffordshire blue brick work in lime mortar crushed
at 114.34 tons, and in cement mortar at 135.43 tons.

The height of a brick pier should not exceed twelve times its least width.
The London Building Act in the first schedule prescribes that in buildings
not public, or of the warehouse class, in no storey shall any external or
party walls exceed in height sixteen times the thickness. In buildings of
the warehouse class, the height of these walls shall not exceed fourteen
times the thickness.

In exposed situations it is necessary to strengthen the buildings by
increasing the thickness of walls and parapets, and to provide heavier
copings and flashings. Special precautions, too, must be observed in the
fixing of copings, chimney pots, ridges and hips. The greatest wind
pressure experienced in England may be taken at 56 lb on a sq. ft., but
this is only in the most exposed positions in the country or on a sea
front. Forty pounds is a sufficient allowance in most cases, and where
there is protection by surrounding trees or buildings 28 lb per sq. ft. is
all that needs to be provided against.

In mixing mortar, particular attention must be paid to the sand with which
the lime or cement is mixed. The best sand is that [Sidenote: Mortar.]
obtained from the pit, being sharp and angular. It is, however, liable to
be mixed with clay or earth, which must be washed away before the sand is
used. Gravel found mixed with it must be removed by screening or sifting.
River sand is frequently used, but is not so good as pit sand on account of
the particles being rubbed smooth by attrition. Sea sand is objectionable
for two reasons; it cannot be altogether freed from a saline taint, and if
it is used the salt attracts moisture and is liable to keep the brickwork
permanently damp. The particles, moreover, are generally rounded by
attrition, caused by the movement of the sea, which makes it less efficient
for mortar than if they retained their original angular forms. Blue or
black mortar, often used for pointing the joints of external brickwork on
account of its greater durability, is made by using foundry sand or smith's
ashes instead of ordinary sand. There are many other substitutes for the
ordinary sand. As an example, fine stone grit may be used with advantage.
Thoroughly burnt clay or ballast, old bricks, clinkers and cinders, ground
to a uniform size and screened from dust, also make excellent substitutes.

Fat limes (that is, limes which are pure, as opposed to "hydraulic" limes
which are burnt from limestone containing some clay) should not be used for
mortar; they are slow-setting, and there is a liability for some of the
mortar, where there is not a free access of air to assist the setting,
remaining soft for some considerable period, often months, thus causing
unequal settlement and possibly failure. Grey stone lime is feebly
hydraulic, and makes a good mortar for ordinary work. It, however, decays
under the influence of the weather, and it is, therefore, advisable to
point the external face of the work in blue ash or cement mortar, in order
to obtain greater durability. It should never be used in foundation work,
or where exposed to wet. Lias lime is hydraulic, that is, it will set firm
under water. It should be used in all good class work, where Portland
cement is not desired.

Of the various cements used in building, it is necessary only to mention
three as being applicable to use for mortar. The first of these is Portland
cement, which has sprung into very general use, not only for work where
extra strength and durability are required, and for underground work, but
also in general building where a small extra cost is not objected to.
Ordinary lime mortar may have its strength considerably enhanced by the
addition of a small proportion of Portland cement. Roman cement is rarely
used for mortar, but is useful in some cases on account of the rapidity
with which it sets, usually becoming hard about fifteen minutes after
mixing. It is useful in tidal work and embankments, and constructions under
water. It has about one-third of the strength of Portland cement, by which
it is now almost entirely supplanted. Selenitic cement or lime, invented by
Major-General H. Y. D. Scott (1822-1883), is lias lime, to which a small
proportion of plaster of Paris has been added with the object of
suppressing the action of slaking and inducing quicker setting. If
carefully mixed in accordance with the instructions issued by the
manufacturers, it will take a much larger proportion of sand than ordinary
lime.

Lime should be slaked before being made into mortar. The lime is measured
out, deposited in a heap on a wooden "bank" or platform, and after being
well watered is covered with the correct proportion of sand. This retains
the heat and moisture necessary to thorough slaking; the time required for
this operation depends on the variety of the lime, but usually it is from a
few hours to one and a half days. If the mixing is to be done by hand the
materials must be screened to remove any unslaked lumps of lime. The
occurrence of these may be prevented by grinding the lime shortly before
use. The mass should then be well "larried," _i.e._ mixed together with the
aid of a long-handled rake called the "larry." Lime mortar should be
tempered for at least two days, roughly covered up with sacks or other
material. Before being used it must be again turned over and well mixed
together. Portland and Roman cement mortars must be mixed as required on
account of their quick-setting properties. In the case of Portland cement
mortar, a quantity sufficient only for the day's use should be "knocked
up," but with Roman cement fresh mixtures must be made several times a day,
as near as possible to the place of using. Cement mortars should never be
worked up after setting has taken place. Care should be taken to obtain the
proper consistency, which is a stiff paste. If the mortar be too thick,
extra labour is involved in its use, and much time wasted. If it be so thin
as to run easily from the trowel, a longer time is taken in setting, and
the wall is liable to settle; also there is danger that the lime or cement
will be killed by the excess of water, or at least have its binding power
affected. It is not advisable to carry out work when the temperature is
below freezing point, but in urgent cases bricklaying may be successfully
done by using unslaked lime mortar. The mortar must be prepared in small
quantities immediately before being used, so that binding action takes
place before it cools. When the wall is left at night time the top course
should be covered up to prevent the penetration of rain into the work,
which would then be destroyed by the action of frost. Bricks used during
frosty weather should be quite dry, and those that have been exposed to
rain or frost should never be employed. The question whether there is any
limit to bricklayers' work in frost is still an open one. Among the members
of the Norwegian Society of Engineers and Architects, at whose meetings the
subject has been frequently discussed, that limit is variously estimated at
between -6° to -8° Réaumur (18½° to 14° Fahr.) and -12° to -15° Réaumur (5°
above to 1¾° below zero Fahr.). It has been proved by hydraulic tests that
good bricklayers' work can be executed at the latter minimum. The
conviction is held that the variations in the opinions held on this subject
are attributable to the degree of care bestowed on the preparation of the
mortar. It is generally agreed, however, that from a practical point of
view, bricklaying should not be carried on at temperatures lower than -8°
to -10° Réaumur (14° to 9½° Fahr.), for as the thermometer falls the
expense of building is greatly increased, owing to a larger proportion of
lime being required.

For grey lime mortar the usual proportion is one part of lime to two or
three parts of sand; lias lime mortar is mixed in similar proportions,
except for work below ground, when equal quantities of lime and sand should
be used. Portland cement mortar is usually in the proportions of one to
three, or five, of sand; good results are obtained with lime mortar
fortified with cement as follows:--one part slaked lime, one part Portland
cement, and seven parts sand. Roman cement mortar should consist of one or
one and a half parts of cement to one part of sand. Selenitic lime mortar
is usually in the proportions of one to four or five, and must be mixed in
a particular manner, the lime being first ground in water in the mortar
mill, and the sand gradually added. Blue or black mortar contains equal
parts of foundry ashes and lime; but is improved by the addition of a
proportion of cement. For setting fire-bricks fire-clay is always used.
Pargetting for rendering inside chimney flues is made of one part of lime
with three parts of cow dung free from straw or litter. No efficient
substitute has been found for this mixture, which should be used fresh. A
mortar that has found approval for tall chimney shafts is composed by
grinding in a mortar-mill one part of blue lias lime with one part each of
sand and foundry ashes. In the external walls of the Albert Hall the mortar
used was one part Portland cement, one part grey Burham lime and six parts
pit sand. The lime was slaked twenty-four hours, and after being mixed
[v.04 p.0524] with the sand for ten minutes the cement was added and the
whole ground for one minute; the stuff was prepared in quantities only
sufficient for immediate use. The by-laws dated 1891, made by the London
County Council under section 16 of the Metropolis Management and Building
Acts Amendment Act 1878, require the proportions of lime mortar to be one
to three of sand or grit, and for cement mortar one to four. Clean soft
water only should be used for the purpose of making mortar.

_Grout_ is thin liquid mortar, and is legitimately used in gauged arches
and other work when fine joints are desired. In ordinary work it is
sometimes used every four or five courses to fill up any spaces that may
have been inadvertently left between the bricks. This at the best is but
doing with grout what should be done with mortar in the operation of laying
the bricks; and filling or flushing up every course with mortar requires
but little additional exertion and is far preferable. The use of grout is,
therefore, a sign of inefficient workmanship, and should not be
countenanced in good work. It is liable, moreover, to ooze out and stain
the face of the brickwork.

_Lime putty_ is pure slaked lime. It is prepared or "run," as it is termed,
in a wooden tub or bin, and should be made as long a time as possible
before being used; at least three weeks should elapse between preparation
and use.

[Illustration: FIG. 3.--Forms of Joints.]

The pointing of a wall, as previously mentioned, is done either with the
bricklaying or at the completion of the work. If the [Sidenote: Pointing.]
pointing is to be of the same mortar as the rest of the work, it would
probably greatly facilitate matters to finish off the work at one operation
with the bricklaying, but where, as in many cases, the pointing is required
to be executed in a more durable mortar, this would be done as the scaffold
is taken down at the completion of the building, the joints being raked out
by the bricklayer to a depth of ½ or ¾ in. By the latter method the whole
face of the work is kept uniform in appearance. The different forms of
joints in general use are clearly shown in fig. 3. Flat or flush joints (A)
are formed by pressing the protruding mortar back flush with the face of
the brickwork. This joint is commonly used for walls intended to be coated
with distemper or limewhite. The flat joint jointed (two forms, B and C) is
a development of the flush joint. In order to increase the density and
thereby enhance the durability of the mortar, a semicircular groove is
formed along the centre, or one on each side of the joint, with an iron
jointer and straight-edge. Another form, rarely used, is the keyed joint
shown at D, the whole width of the joint in this case being treated with
the curved key. Struck or bevelled, or weathered, joints have the upper
portion pressed back with the trowel to form a sloping surface, which
throws off the wet. The lower edge is cut off with the trowel to a straight
edge. This joint is in very common use for new work. Ignorant workmen
frequently make the slope in the opposite direction (F), thus forming a
ledge on the brick; this catches the water, which on being frozen rapidly
causes the disintegration of the upper portion of the brick and of the
joint itself. With recessed jointing, not much used, a deep shadow may be
obtained. This form of joint, illustrated in G, is open to very serious
objections, for it encourages the soaking of the brick with rain instead of
throwing off the wet, as it seems the natural function of good pointing,
and this, besides causing undue dampness in the wall, renders it liable to
damage by frost. It also leaves the arrises of the bricks unprotected and
liable to be damaged, and from its deep recessed form does not make for
stability in the work. Gauged work has very thin joints, as shown at H,
formed by dipping the side of the brick in white lime putty. The sketch I
shows a joint raked out and filled in with pointing mortar to form a flush
joint, or it may be finished in any of the preceding forms. Where the wall
is to be plastered the joints are either left open or raked out, or the
superfluous mortar may be left protruding as shown at J. By either method
an excellent key is obtained, to which the rendering firmly adheres. In
tuck pointing (K) the joints are raked out and stopped, i.e. filled in
flush with mortar coloured to match the brickwork. The face of the wall is
then rubbed over with a soft brick of the same colour, or the work may be
coloured with pigment. A narrow groove is then cut in the joints, and the
mortar allowed to set. White lime putty is next filled into the groove,
being pressed on with a jointing tool, leaving a white joint 1/8 to ¼ in.
wide, and with a projection of about 1/16 in. beyond the face of the work.
This method is not a good or a durable one, and should only be adopted in
old work when the edges of the bricks are broken or irregular. In bastard
tuck pointing (L), the ridge, instead of being in white lime putty, is
formed of the stopping mortar itself.

Footings, as will be seen on reference to fig. 1, are the wide courses of
brickwork at the base or foot of a wall. They serve to spread [Sidenote:
Footings.] the pressure over a larger area of ground, offsets 2¼ in. wide
being made on each side of the wall until a width equal to double the
thickness of the wall is reached. Thus in a wall 13½ in. (1½ bricks) thick,
this bottom course would be 2 ft. 3 in. (3 bricks) wide. It is preferable
for greater strength to double the lowest course. The foundation bed of
concrete then spreading out an additional 6 in. on each side brings the
width of the surface bearing on the ground to 3 ft. 3 in. The London
Building Act requires the projection of concrete on each side of the
brickwork to be only 4 in., but a projection of 6 in. is generally made to
allow for easy working. Footings should be built with hard bricks laid
principally as headers; stretchers, if necessary, should be placed in the
middle of the wall.

[Illustration: FIG. 4.--Diagram of Bonding.]

Bond in brickwork is the arrangement by which the bricks of every course
cover the joints of those in the course below it, and so [Sidenote:
Bonding.] tend to make the whole mass or combination of bricks act as much
together, or as dependently one upon another, as possible. The workmen
should be strictly supervised as they proceed with the work, for many
failures are due to their ignorance or carelessness in this particular. The
object of bonding will be understood by reference to fig. 4. Here it is
evident from the arrangement of the bricks that any weight placed on the
topmost brick (a) is carried down and borne alike in every course; in this
way the weight on each brick is distributed over an area increasing with
every course. But this forms a longitudinal bond only, which cannot extend
its influence beyond the width of the brick; and a wall of one brick and a
half, or two bricks, thick, built in this manner, would in effect consist
of three or four half brick thick walls acting independently of each other.
If the bricks were turned so as to show their short sides or ends in front
instead of their long ones, certainly a compact wall of a whole brick
thick, instead of half a brick, would be produced, and while the thickness
of the wall would be double, the longitudinal bond would be shortened by
one-half: a wall of any great thickness built in this manner would
necessarily be composed of so many independent one-brick walls. To produce
a transverse and yet preserve a true longitudinal bond, the bricks are laid
in a definite arrangement of stretchers and headers.

[Illustration: FIG. 5.--English Bond.

In this and following illustration of bond in brickwork the position of
bricks in the second course is indicated by dotted lines.]

In "English bond" (fig. 5), rightly considered the most perfect in use, the
bricks are laid in alternate courses of headers and stretchers, thus
combining the advantages of the two previous modes of arrangement. A
reference to fig. 5 will show how the process of bonding is pursued in a
wall one and a half bricks in thickness, and how the quoins are formed. In
walls which are a multiple of a whole brick, the appearance of the same
course is similar on the elevations of the front and back faces, but in
walls where an odd half brick must be used to make up the thickness, as is
the case in the illustration, the appearance of the opposite sides of a
course is inverted. The example illustrates the principle of English bond;
thicker walls are constructed in the same manner by an extension of the
same methods. It will be observed that portions of a brick have to be
inserted near a vertical end or a quoin, in order to start the regular
bond. These portions equal a half header in width, and are called queen
closers; they are placed next to the first header. A three-quarter brick is
obviously as available for this purpose as a header and closer combined,
but the latter method is preferred because by the use of it uniformity of
appearance is preserved, and whole bricks are retained on the returns. King
closers are used at rebated openings formed in walls in Flemish bond, and
by reason of the greater width of the back or "tail," add strength to the
work. They are cut on the splay so that the front end is half the width of
a header and one side half the length of the brick. An example of their use
will be seen in fig. 15. In walls of almost all thicknesses above 9 in.,
except in the [v.04 p.0525] English bond, to preserve the transverse and
yet not destroy the longitudinal bond, it is frequently necessary to use
half bricks. It may be taken as a general rule that a brick should never be
cut if it can be worked in whole, for a new joint is thereby created in a
construction, the difficulty of which consists in obviating the debility
arising from the constant recurrence of joints. Great insistence must be
laid on this point, especially at the junctions of walls, where the
admission of closers already constitutes a weakness which would only be
increased by the use of other bats or fragments of bricks.

[Illustration: FIG. 6.--Flemish Bond.]

Another method of bonding brickwork, instead of placing the bricks in
alternate courses of headers and stretchers, places them alternately as
headers and stretchers in the same course, the appearance of the course
being the same on each face. This is called "Flemish bond." Closers are
necessary to this variety of bond. From fig. 6 it will be seen that, owing
to the comparative weakness of the transverse tie, and the numbers of half
bricks required to be used and the thereby increased number of joints, this
bond is not so perfect nor so strong as English. The arrangements of the
face joints, however, presenting in Flemish bond a neater appearance than
in English bond, it is generally selected for the external walls of
domestic and other buildings where good effect is desirable. In buildings
erected for manufacturing and similar purposes, and in engineering works
where the greatest degree of strength and compactness is considered of the
highest importance, English bond should have the preference.

A compromise is sometimes made between the two above-mentioned bonds. For
the sake of appearance the bricks are laid to form Flemish bond on the
face, while the backing is of English bond, the object being to combine the
best features of the two bonds. Undoubtedly the result is an improvement on
Flemish bond, obviating as it does the use of bats in the interior of the
wall. This method of bonding is termed "single Flemish bond," and is shown
in fig. 7.

In stretching bond, which should only be used for walls half a brick in
thickness, all the bricks are laid as stretchers, a half brick being used
in alternate courses to start the bond. In work curved too sharply on plan
to admit of the use of stretchers, and for footings, projecting mouldings
and corbels, the bricks are all laid as headers, i.e. with their ends to
the front, and their length across the thickness of the wall. This is
termed "heading bond."

[Illustration: FIG. 7.--Single Flemish Bond.]

In thick walls, three bricks thick and upwards, a saving of labour is
effected without loss of strength, by the adoption of "herring bone" or
"diagonal bond" in the interior of the wall, the outer faces of the wall
being built in English and Flemish bond. This mode should not be had
recourse to for walls of a less thickness than 27 in., even that being
almost too thin to admit of any great advantage from it.

Hoop-iron, about 1½ in. wide and 1/16 in. thick, either galvanized or well
tarred and sanded to retard rusting, is used in order to obtain additional
longitudinal tie. The customary practice is to use one strip of iron for
each half-brick in thickness of the wall. Joints at the angles, and where
necessary in the length, are formed by bending the ends of the strips so as
to hook together. A patent stabbed iron now on the market is perforated to
provide a key for the mortar.

A difficulty often arises in bonding when facing work with bricks of a
slightly different size from those used in "backing," as it is technically
termed. As it is, of course, necessary to keep all brickwork in properly
levelled courses, a difference has to be made in the thickness of the
mortar joints. Apart from the extra labour involved, this obviously is
detrimental to the stability of the wall, and is apt to produce unequal
settlement and cracking. Too much care cannot be taken to obtain both
facing and backing bricks of equal size.

[Illustration: FIG. 8.]

Dishonest bricklayers do not hesitate, when using for the face of a wall
bricks of a quality superior to those used for the interior, to use
"snapped headers," that is cutting the heading bricks in halves, one brick
thus serving the purposes of two as regards outward appearance. This is a
most pernicious practice, unworthy of adoption by any craftsman of repute,
for a skin of brickwork 4½ in. thick is thus carried up with a straight
mortar joint behind it, the proper bonding with the back of the wall by
means of headers being destroyed.

American building acts describe the kind of bond to be used for ordinary
walls, and the kind for faced walls. Tie courses also require an extra
thickness where walls are perforated with over 30% of flues.

The importance for sanitary and other reasons of keeping walls dry is
admitted by all who have observed the deleterious action of damp upon a
building.

Walls are liable to become damp, (1) by wet rising up the wall from the
earth; (2) by water soaking down from the top of the [Sidenote: Prevention
of damp.] wall; (3) by rain being driven on to the face by wind. Dampness
from the first cause may be prevented by the introduction of damp-proof
courses or the construction of dry areas; from the second by means of a
coping of stone, cement or other non-porous material; and from the third by
covering the exterior with impervious materials or by the adoption of
hollow walls.

[Illustration: FIG. 9.]

After the footings have been laid and the wall has been brought up to not
less than 6 in. above the finished surface of the ground, and previous to
fixing the plate carrying the ground floor, there should always be
introduced a course of some damp-proof material to prevent the rise of
moisture from the soil. There are several forms of damp-proof course. A
very usual one is a double layer of roofing slates laid in neat Portland
cement (fig. 8), the joints being well lapped. A course or two of
Staffordshire blue bricks in cement is excellent where heavy weights have
to be considered. Glazed stoneware perforated slabs about 2 in. thick are
specially made for use as damp-proof courses. Asphalt (fig. 9) recently has
come into great favour with architects; a layer ½ or ¾ in. thick is a good
protection against damp, and not likely to crack should a settlement occur,
but in hot weather it is liable to squeeze out at the joints under heavy
weights. Felt covered with bitumen is an excellent substitute for asphalt,
and is not liable to crack or squeeze out. Sheet lead is efficient, but
very costly and also somewhat liable to squeezing. A damp-proof course has
been introduced consisting of a thin sheet of lead sandwiched between
layers of asphalt. Basement storeys to be kept dry require, besides the
damp-proof course horizontally in the wall, a horizontal course, usually of
asphalt, in the thickness of the floor, and also a vertical damp-proof
course from a level below that of the floor to about 6 in. above the level
of the ground, either built in the thickness of the wall or rendered on the
outside between the wall and the surrounding earth (fig. 10).

By means of dry areas or air drains (figs. 11 and 12), a hollow [v.04
p.0526] space 9 in. or more in width is formed around those portions of the
walls situated below the ground, the object being to prevent them from
coming into contact with the brickwork of the main walls and so imparting
its moisture to the building. Arrangements should be made for keeping the
area clear of vermin and for ventilating and draining it. Dry areas, being
far from sanitary, are seldom adopted now, and are being superseded by
asphalt or cement applied to the face of the wall.

[Illustration: FIG. 10.]

[Illustration: FIG. 11.]

[Illustration: FIG. 12.]

Moisture is prevented from soaking down from the top of the wall by using a
covering of some impervious material in the form of a coping. This may
consist of ordinary bricks set on edge in cement with a double course of
tiles immediately below, called a "creasing," or of specially made
non-porous coping bricks, or of stone, cast-iron, or cement sloped or
"weathered" in order to throw the rain off.

[Illustration: FIG. 13.]

The exterior of walls above the ground line may be protected by coating the
surface with cement or rough cast; or covering with slates or tiles fixed
on battens in a similar manner to those on a roof (fig.13).

The use of hollow walls in exposed positions has already been referred to.

The by-laws dated 1891, made by the London County Council under section 16
of the Metropolis Management and Buildings Acts Amendment Act 1878, require
that "every wall of a house or building shall have a damp course composed
of materials impervious to moisture approved by the district surveyor,
extending throughout its whole thickness at the level of not less than 6
in. below the level of the lowest floor. Every external wall or enclosing
wall of habitable rooms or their appurtenances or cellars which abuts
against the earth shall be protected by materials impervious to moisture to
the satisfaction of the district surveyor..." "The top of every party-wall
and parapet-wall shall be finished with one course of hard, well-burnt
bricks set on edge, in cement, or by a coping of any other waterproof and
fire-resisting material, properly secured."

Arches are constructions built of wedge-shaped blocks, which by reason of
their shape give support one to another, and to the [Sidenote: Arches.]
super-imposed weight, the resulting load being transmitted through the
blocks to the abutments upon which the ends of the arch rest. An arch
should be composed of such materials and designed of such dimensions as to
enable it to retain its proper shape and resist the crushing strain imposed
upon it. The abutments also must be strong enough to take safely the thrust
of the weighted arch, as the slightest movement in these supports will
cause deflection and failure. The outward thrust of an arch decreases as it
approaches the semicircular form, but the somewhat prevalent idea that in
the latter form no thrusting takes place is at variance with fact.

[Illustration: FIG. 14.]

Arches in brickwork may be classed under three heads: plain arches,
rough-cut and gauged. Plain arches are built of uncut bricks, and since the
difference between the outer and inner periphery of the arch requires the
parts of which an arch is made up to be wedge-formed, which an ordinary
brick is not, the difference must be made in mortar, with the result that
the joints become wedge-shaped. This obviously gives an objectionable
inconsistency of material in the arch, and for this reason to obtain
greatest strength it is advisable to build these arches in independent
rings of half-brick thickness. The undermost rings should have thin joints,
those of each succeeding ring being slightly thickened. This prevents the
lowest ring from settling while those above remain in position, which would
cause an ugly fissure. In work of large span bonding blocks or "lacing
courses" should be built into the arch, set in cement and running through
its thickness at intervals, care being taken to introduce the lacing course
at a place where the joints of the various rings coincide. Stone blocks in
the shape of a voussoir (fig. 14) may be used instead. Except for these
lacing courses hydraulic lime mortar should be used for large arches, on
account of its slightly accommodating nature.

Rough-cut arches are those in which the bricks are roughly cut with an axe
to a wedge form; they are used over openings, such as doors and windows,
where a strong arch of neat appearance is desired. The joints are usually
made equal in width to those of the ordinary brickwork. Gauged arches are
composed of specially made soft bricks, which are cut and rubbed to gauges
or templates so as to form perfectly fitting voussoirs. Gauging is, of
course, equally applicable to arches and walling, as it means no more than
bringing every brick exactly to a certain form by cutting and rubbing.
Gauged brickwork is set in lime putty instead of common mortar; the
finished joints should not be more than 1/32 in. wide. To give stability
the sides of the voussoirs are gauged out hollow and grouted in Portland
cement, thus connecting each brick with the next by a joggle joint. Gauged
arches, being for the most part but a half-brick in thickness on the soffit
and not being tied by a bond to anything behind them--for behind them is
the lintel with rough discharging arch over, supporting the remaining width
of the wall--require to be executed with great care and nicety. It is a
common fault with workmen to rub the bricks thinner behind than before to
lessen the labour required to obtain a very fine face joint. This practice
tends to make the work bulge outwards; it should rather be inverted if it
be done at all, though the best work is that in which the bricks are gauged
to exactly the same thickness at the back as at the front. The same fault
occurs when a gauged arch is inserted in an old wall, on account of the
difficulty of filling up with cement the space behind the bricks.

The bond of an arch obtains its name from the arrangement of headers and
stretchers on its soffit. The under side of an arch built in English bond,
therefore, will show the same arrangement as the face of a wall built in
English bond. If the arch is in Flemish the soffit presents the same
appearance as the elevation of a wall built in that bond.

It is generally held that the building of wood into brickwork [Sidenote:
Plates.] should as far as is possible be avoided. Wall plates of wood are,
however, necessary where wood joists are used, and where these plates may
not be supported on corbels of projecting brickwork or iron they must be
let flush into the wall, taking the place of a course of bricks. They form
a uniform bed for the joists, to which easy fixing is obtained. The various
modes adopted for resting and fixing the ends of joists on walls are
treated in the article CARPENTRY.

[Illustration: FIG. 15.]

Lintels, which may be of iron, steel, plain or reinforced concrete, or
stone, are used over square-headed openings instead of or in conjunction
with arches. They are useful to preserve the square form and receive the
joiners' fittings, but except when made of steel or of concrete reinforced
with steel bars, they should have relieving arches turned immediately over
them (Fig.15).

"Fixing bricks" were formerly of wood of the same size as the ordinary
brick, and built into the wall as required for fixing joinery. Owing to
their liability to shrinkage and decay, their use is now practically
abandoned, their place being taken by bricks of coke-breeze concrete, which
do not shrink or rot and hold fast nails or screws driven into them.
Another method often adopted for [v.04 p.0527] providing a fixing for
joinery is to build in wood slips the thickness of a joint and 4½ in. wide.
When suitable provision for fixing has not been made, wood plugs are driven
into the joints of the bricks. Great care must be taken in driving these in
the joints of reveals or at the corners of walls, or damage may be done.

The name "brick-ashlar" is given to walls faced with ashlar stonework
backed in with brickwork. Such constructions are liable in an aggravated
degree to the unequal settling and its attendant evils pointed out as
existing in walls built with different qualities of bricks. The outer face
is composed of unyielding stone with few and very thin joints, which
perhaps do not occupy more than a hundredth part of its height, while the
back is built up of bricks with about one-eighth its height composed of
mortar joints, that is, of a material that by its nature and manner of
application must both shrink in drying and yield to pressure. To obviate
this tendency to settle and thus cause the bulging of the face or failure
of the wall, the mortar used should be composed of Portland cement and sand
with a large proportion of the former, and worked as stiff as it
conveniently can be. In building such work the stones should be in height
equal to an exact number of brick courses. It is a common practice in
erecting buildings with a facing of Kentish rag rubble to back up the
stonework with bricks. Owing to the great irregularity of the stones, great
difficulty is experienced in obtaining proper bond between the two
materials. Through bonding stones or headers should be frequently built in,
and the whole of the work executed in cement mortar to ensure stability.

Not the least important part of the bricklayer's art is the formation of
chimney and other flues. Considerable skill is required in [Sidenote:
Chimneys and flues.] gathering-over properly above the fireplace so as to
conduct the smoke into the smaller flue, which itself requires to be built
with precision, so that its capacity may not vary in different parts. Bends
must be made in gradual curves so as to offer the least possible resistance
to the up-draught, and at least one bend of not less than 60° should be
formed in each flue to intercept down-draughts. Every fireplace must have a
separate flue. The collection of a number of flues into a "stack" is
economical, and tends to increase the efficiency of the flues, the heat
from one flue assisting the up-draught in those adjoining it. It is also
desirable from an aesthetic point of view, for a number of single flue
chimneys sticking up from various parts of the roof would appear most
unsightly. The architects of the Elizabethan and later periods were masters
of this difficult art of treating a stack or stacks as an architectural
feature. The shaft should be carried well above the roof, higher, if
possible, than adjacent buildings, which are apt to cause down-draught and
make the chimney smoke. When this is found impossible, one of the many
forms of patent chimney-pots or revolving cowls must be adopted. Each flue
must be separated by smoke-proof "withes" or divisions, usually half a
brick in thickness; connexion between them causes smoky chimneys. The size
of the flue for an ordinary grate is 14×9 in.; for a kitchen stove 14×14
in. The outer wall of a chimney stack may with advantage be made 9 in.
thick. Fireclay tubes, rectangular or circular in transverse section, are
largely used in place of the pargetting; although more expensive than the
latter they have the advantage in point of cleanliness and durability.
Fireplaces generally require more depth than can be provided in the
thickness of the wall, and therefore necessitate a projection to contain
the fireplace and flues, called the "chimney breast." Sometimes, especially
when the wall is an external one, the projection may be made on the back,
thus allowing a flush wall in the room and giving more space and a more
conveniently-shaped room. The projection on the outside face of the wall
may be treated as an ornamental feature. The fireplace opening is covered
by a brick relieving arch, which is fortified by wrought-iron bar from ½ to
¾ in. thick and 2 to 3 in. wide. It is usually bent to a "camber," and the
brick arch built upon it naturally takes the same curve. Each end is
"caulked," that is, split longitudinally and turned up and down. The
interior of a chimney breast behind the stove should always be filled in
solid with concrete or brickwork. The flooring in the chimney opening is
called the "hearth"; the back hearth covers the space between the jambs of
the chimney breast, and the front hearth rests upon the brick "trimmer
arch" designed to support it. The hearth is now often formed in solid
concrete, supported on the brick wall and fillets fixed to the floor
joists, without any trimmer arch and finished in neat cement or glazed
tiles instead of stone slabs.

Tall furnace chimneys should stand as separate constructions, unconnected
with other buildings. If it is necessary to bring other work close up, a
straight joint should be used. The shaft of the chimney will be built
"overhand," the men working from the inside. Lime mortar is used, cement
being too rigid to allow the chimney to rock in the wind. Not more than 3
ft. in height should be erected in one day, the work of necessity being
done in small portions to allow the mortar to set before it is required to
sustain much weight. The bond usually adopted is one course of headers to
four of stretchers. Scaffolding is sometimes erected outside for a height
of 25 or 30 ft., to facilitate better pointing, especially where the
chimney is in a prominent position. The brickwork at the top must,
according to the London Building Act, be 9 in. thick (it is better 14 in.
in shafts over 100 ft. high), increasing half a brick in thickness for
every additional 20 ft. measured downwards. "The shaft shall taper
gradually from the base to the top at the rate of at least 2½ in. in 10 ft.
of height. The width of the base of the shaft if square shall be at least
one-tenth of the proposed height of the shaft, or if round or any other
shape, then one-twelfth of the height. Firebricks built inside the lower
portion of the shaft shall be provided, as additional to and independent of
the prescribed thickness of brickwork, and shall not be bonded therewith."
The firebrick lining should be carried up from about 25 ft. for ordinary
temperatures to double that height for very great ones, a space of 1½ to 3
in. being kept between the lining and the main wall. The lining itself is
usually 4½ in. thick. The cap is usually of cast iron or terra-cotta
strengthened with iron bolts and straps, and sometimes of stone, but the
difficulty of properly fixing this latter material causes it to be
neglected in favour of one of the former. (See a paper by F.J. Bancroft on
"Chimney Construction," which contains a tabulated description of nearly
sixty shafts, _Proc. Civ. and Mech. Eng. Soc._, December 1883.)

The work of laying bricks or tiles as paving falls to the lot of the
bricklayer. Paving formed of ordinary bricks laid flat or on their
[Sidenote: Brick paving.] edges was once in general use, but is now almost
abandoned in favour of floors of special tiles or cement paving, the latter
being practically non-porous and therefore more sanitary and cleaner.
Special bricks of extremely hard texture are made for stable and similar
paving, having grooves worked on the face to assist drainage and afford
good foothold. A bed of concrete 6 in. thick is usually provided under
paving, or when the bricks are placed on edge the concrete for external
paving may be omitted and the bricks bedded in sand, the ground being
previously well rammed. The side joints of the bricks are grouted in with
lime or cement. Dutch clinkers are small, hard paving bricks burned at a
high temperature and of a light yellow colour; they are 6 in. long, 3 in.
wide, 1½ in. thick. A variety of paving tile called "oven tiles" is of
similar material to the ordinary red brick, and in size is 10 or 12 in.
square and 1 to 2 in. thick. An immense variety of ornamental paving and
walling tiles is now manufactured of different colours, sizes and shapes,
and the use of these for lining sculleries, lavatories, bathrooms,
provision shops, &c., makes for cleanliness and improved sanitary
conditions. Besides, however, being put to these uses, tiles are often used
in the ornamentation of buildings, externally as well as internally.

Mosaic work is composed of small pieces of marble, stone, glass or pottery,
laid as paving or wall lining, usually in some ornamental pattern or
design. A firm bed of concrete is required, the pieces of [v.04 p.0528]
material being fixed in a float of cement about half or three-quarters of
an inch thick. Roman mosaic is formed with cubes of marble of various
colours pressed into the float. A less costly paving may be obtained by
strewing irregularly-shaped marble chips over the floated surface: these
are pressed into the cement with a plasterer's hand float, and the whole is
then rolled with an iron roller. This is called "terazzo mosaic." In either
the Roman or terazzo method any patterns or designs that are introduced are
first worked in position, the ground-work being filled in afterwards. For
the use of cement for paving see PLASTER.

The principal publications on brickwork are as follows:--Rivington, _Notes
on Building Construction_, vols. i. ii. iii.; Col. H.E. Seddon, _Aide
Memoir_, vol. ii.; _Specification_; J.P. Allen, _Building Construction_;
F.E. Kidder, _Building Construction and Superintendence_, part i. (1903);
Longmans & Green, _Building Construction_; E. Dobson, _Bricks and Tiles_;
Henry Adams, _Building Construction_; C.F. Mitchell, _Building
Construction_, vols. i. ii.; E. Street, _Brick and Marble Architecture in
Italy_.

(J. BT.)

BRICOLE (a French word of unknown origin), a military engine for casting
heavy stones; also a term in tennis for a sidestroke rebounding off the
wall of the court, corrupted into "brickwall" from a supposed reference to
the wall, and in billiards for a stroke off the cushion to make a cannon or
hazard.

BRIDAINE (or BRYDAYNE), JACQUES (1701-1767), French Roman Catholic
preacher, was born at Chuslan in the department of Gard on the 21st of
March 1701. He was educated at Avignon, first in the Jesuit college and
afterwards at the Sulpician seminary of St Charles. Soon after his
ordination to the priesthood in 1725, he joined the _Missions Royales_,
organized to bring back to the Catholíc faith the Protestants of France. He
gained their good-will and made many converts; and for over forty years he
visited as a missionary preacher almost every town of central and southern
France. In Paris, in 1744, his sermons created a deep impression by their
eloquence and sincerity. He died at Roquemaure, near Avignon, on the 22nd
of December 1767. He was the author of _Cantiques spirituels_ (Montpelier,
1748, frequently reprinted, in use in most French churches); his sermons
were published in 5 vols. at Avignon in 1823 (ed. Paris, 1861).

See Abbé G. Carron, _Le Modèle des prêtres_ (1803).

BRIDE (a common Teutonic word, e.g. Goth. _bruths_, O.Eng. _bryd_, O.H.Ger.
_prût_, Mod. Ger. _Braut_, Dut. _bruid_, possibly derived from the root
_bru-_, cook, brew; from the med. latinized form _bruta_, in the sense of
daughter-in-law, is derived the Fr. _bru_), the term used of a woman on her
wedding-day, and applicable during the first year of wifehood. It appears
in combination with many words, some of them obsolete. Thus "bridegroom" is
the newly married man, and "bride-bell," "bride-banquet" are old
equivalents of wedding-bells, wedding-breakfast. "Bridal" (from
_Bride-ale_), originally the wedding-feast itself, has grown into a general
descriptive adjective, e.g. the _bridal_ party, the _bridal_ ceremony. The
_bride-cake_ had its origin in the Roman _confarreatio_, a form of
marriage, the essential features of which were the eating by the couple of
a cake made of salt, water and flour, and the holding by the bride of three
wheat-ears, symbolical of plenty. Under Tiberius the cake-eating fell into
disuse, but the wheat ears survived. In the middle ages they were either
worn or carried by the bride. Eventually it became the custom for the young
girls to assemble outside the church porch and throw grains of wheat over
the bride, and afterwards a scramble for the grains took place. In time the
wheat-grains came to be cooked into thin dry biscuits, which were broken
over the bride's head, as is the custom in Scotland to-day, an oatmeal cake
being used. In Elizabeth's reign these biscuits began to take the form of
small rectangular cakes made of eggs, milk, sugar, currants and spices.
Every wedding guest had one at least, and the whole collection were thrown
at the bride the instant she crossed the threshold. Those which lighted on
her head or shoulders were most prized by the scramblers. At last these
cakes became amalgamated into a large one which took on its full glories of
almond paste and ornaments during Charles II.'s time. But even to-day in
rural parishes, e.g. north Notts, wheat is thrown over the bridal couple
with the cry "Bread for life and pudding for ever," expressive of a wish
that the newly wed may be always affluent. The throwing of rice, a very
ancient custom but one later than the wheat, is symbolical of the wish that
the bridal may be fruitful. The _bride-cup_ was the bowl or loving-cup in
which the bridegroom pledged the bride, and she him. The custom of breaking
this wine-cup, after the bridal couple had drained its contents, is common
to both the Jews and the members of the Greek Church. The former dash it
against the wall or on the ground, the latter tread it under foot. The
phrase "bride-cup" was also sometimes used of the bowl of spiced wine
prepared at night for the bridal couple. _Bride-favours_, anciently called
bride-lace, were at first pieces of gold, silk or other lace, used to bind
up the sprigs of rosemary formerly worn at weddings. These took later the
form of bunches of ribbons, which were at last metamorphosed into rosettes.
_Bridegroom-men_ and _bridesmaids_ had formerly important duties. The men
were called bride-knights, and represented a survival of the primitive days
of marriage by capture, when a man called his friends in to assist to
"lift" the bride. Bridesmaids were usual in Saxon England. The senior of
them had personally to attend the bride for some days before the wedding.
The making of the bridal wreath, the decoration of the tables for the
wedding feast, the dressing of the bride, were among her special tasks. In
the same way the senior groomsman (the _best man_) was the personal
attendant of the husband. The _bride-wain_, the wagon in which the bride
was driven to her new home, gave its name to the weddings of any poor
deserving couple, who drove a "wain" round the village, collecting small
sums of money or articles of furniture towards their housekeeping. These
were called bidding-weddings, or bid-ales, which were in the nature of
"benefit" feasts. So general is still the custom of "bidding-weddings" in
Wales, that printers usually keep the form of invitation in type. Sometimes
as many as six hundred couples will walk in the bridal procession. The
_bride's wreath_ is a Christian substitute for the gilt coronet all Jewish
brides wore. The crowning of the bride is still observed by the Russians,
and the Calvinists of Holland and Switzerland. The wearing of orange
blossoms is said to have started with the Saracens, who regarded them as
emblems of fecundity. It was introduced into Europe by the Crusaders. The
_bride's veil_ is the modern form of the _flammeum_ or large yellow veil
which completely enveloped the Greek and Roman brides during the ceremony.
Such a covering is still in use among the Jews and the Persians.

See Brand, _Antiquities of Great Britain_ (Hazlitt's ed., 1905); Rev J.
Edward Vaux, _Church Folklore_ (1894).

BRIDEWELL, a district of London between Fleet Street and the Thames, so
called from the well of St Bride or St Bridget close by. From William the
Conqueror's time, a castle or Norman tower, long the occasional residence
of the kings of England, stood there by the Fleet ditch. Henry VIII., Stow
says, built there "a stately and beautiful house," specially for the
housing of the emperor Charles V. and his suite in 1525. During the hearing
of the divorce suit by the Cardinals at Blackfriars, Henry and Catharine of
Aragon lived there. In 1553 Edward VI. made it over to the city as a
penitentiary, a house of correction for vagabonds and loose women; and it
was formally taken possession of by the lord mayor and corporation in 1555.
The greater part of the building was destroyed in the Great Fire of 1666.
New Bridewell, built in 1829, was pulled down in 1864. The term has become
a synonym for any reformatory.

BRIDGE, a game of cards, developed out of the game of whist. The country of
its origin is unknown. A similar game is said to have been played in
Denmark in the middle of the 19th century. A game in all respects the same
as bridge, except that in "no trumps" each trick counted ten instead of
twelve, was played in England about 1884 under the name of Dutch whist.
Some connect it with Turkey and Egypt under the name of "Khedive," or with
a Russian game called "Yeralash." It was in Turkey that it first won a
share of popular favour. Under the synonyms of "Biritch," "Bridge," or
"Russian whist," it found its way to the London clubs about 1894, from
which date its popularity rapidly increased.

_Ordinary Bridge._--Bridge, in its ordinary form, differs from [v.04
p.0529] whist in the following respects:--Although there are four players,
yet in each hand the partner of the dealer takes no part in the play of
that particular hand. After the first lead his cards are placed on the
table exposed, and are played by the dealer as at dummy whist; nevertheless
the dealer's partner is interested in the result of the hand equally with
the dealer. The trump suit is not determined by the last card dealt, but is
selected by the dealer or his partner without consultation, the former
having the first option. It is further open to them to play without a trump
suit. The value of tricks and honours varies with the suit declared as
trumps. Honours are reckoned differently from whist, and on a scale which
is somewhat involved. The score for honours does not count towards winning
or losing the rubber, but is added afterwards to the trick score in order
to determine the value of the rubber. There are also scores for holding no
trumps ("chicane"), and for winning all the tricks or all but one ("slam").

The score has to be kept on paper. It is usual for the scoring block to
have two vertical columns divided halfway by a horizontal line. The left
column is for the scorers' side, and the right for the opponents'. Honours
are scored above the horizontal line, and tricks below. The drawback to
this arrangement is that, since the scores for each hand are not kept
separately, it is generally impossible to trace an error in the score
without going through the whole series of hands. A better plan, it seems,
is to have four columns ruled, the inner two being assigned to tricks, the
outer ones to honours. By this method a line can be reserved for each hand,
and any discrepancy in the scores at once rectified.

The Portland Club, London, drew up a code of laws in 1895, and this code,
with a few amendments, was in July 1895 adopted by a joint committee of the
Turf and Portland Clubs. A revised code came into force in January 1905,
the provisions of which are here summarized.

Each trick above 6 counts 2 points in a spade declaration, 4 in a club, 6
in a diamond, 8 in a heart, 12 in a no-trump declaration. The game consists
of 30 points made by tricks alone. When one side has won two games the
rubber is ended. The winners are entitled to add 100 points to their score.
Honours consist of ace, king, queen, knave, ten, in a suit declaration. If
a player and his partner conjointly hold 3 (or "simple") honours they score
twice the value of a trick; if 4 honours, 4 times; if 5 honours, 5 times.
If a player in his own hand hold 4 honours he is entitled to score 4
honours in addition to the score for conjoint honours; thus, if one player
hold 4 honours and his partner the other their total score is 9 by honours.
Similarly if a player hold 5 honours in his own hand he is entitled to
score 10 by honours. If in a no-trump hand the partners conjointly hold 3
aces, they score 30 for honours; if 4 aces, 40 for honours. 4 aces in 1
hand count 100. On the same footing as the score for honours are the
following: _chicane_, if a player hold no trump, in amount equal to simple
honours; _grand slam_, if one side win all the tricks, 40 points; _little
slam_, if they win 12 tricks, 20 points. At the end of the rubber the total
scores, whether made by tricks, honours, chicane, slam, or rubber points,
are added together, and the difference between the two totals is the number
of points won.

At the opening of play, partners are arranged and the cards are shuffled,
cut and dealt (the last card not being turned) as at whist; but the dealer
cannot lose the deal by misdealing. After the deal is completed, the dealer
makes the trump or no-trump (_sans atout_) declaration, or passes the
choice to his partner without remark. If the dealer's partner make the
declaration out of his turn, the adversary on the dealer's left may,
without consultation, claim a fresh deal. If an adversary make a
declaration, the dealer may claim a fresh deal or disregard the
declaration. Then after the declaration, either adversary may double, the
leader having first option. The effect of doubling is that each trick is
worth twice as many points as before; but the scores for honours, chicane
and slam are unaltered. If a declaration is doubled, the dealer and his
partner have the right of redoubling, thus making each trick worth four
times as much as at first. The declarer has the first option. The other
side can again redouble, and so on; but the value of a trick is limited to
100 points. In the play of the hand the laws are nearly the same as the
laws of whist, except that the dealer may expose his cards and lead out of
turn without penalty; after the second hand has played, however, he can
only correct this lead out of turn with the permission of the adversaries.
Dummy cannot revoke. The dealer's partner may take no part in the play of
the hand beyond guarding the dealer against revoking.

_Advice to Players._--In the choice of a suit two objects are to be aimed
at: first, to select the suit in which the combined forces have the best
chance of making tricks; secondly, to select the trump so that the value of
the suit agrees with the character of the hand, _i.e._ a suit of high value
when the hands are strong and of low value when very weak. As the deal is a
great advantage it generally happens that a high value is to be aimed at,
but occasionally a low value is desirable. The task of selection should
fall to the hand which has the most distinctive features, that is, either
the longest suit or unusual strength or weakness. No consultation being
allowed, the dealer must assume only an average amount of variation from
the normal in his partner's hand. If his own hand has distinctive features
beyond the average, he should name the trump suit himself, otherwise pass
it to his partner. It may here be stated what is the average in these
respects.

As regards the length of a suit, a player's long suit is rather more likely
to be fewer than five than over five. If the dealer has in his hand a suit
of five cards including two honours, it is probable that he has a better
suit to make trumps than dummy; if the suit is in hearts, and the dealer
has a fair hand, he ought to name the trump. As regards strength, the
average hand would contain ace, king, queen, knave and ten, or equivalent
strength. Hands stronger or weaker than this by the value of a king or less
may be described as featureless. If the dealer's hand is a king over the
average, it is more likely than not that his partner will either hold a
stronger hand, or will hold such a weak hand as will counteract the
player's strength. The dealer would not generally with such a hand declare
no trump, especially as by making a no-trump declaration the dealer
forfeits the advantage of holding the long trumps.

_Declarations by Dealer._--In calculating the strength of a hand a knave is
worth two tens, a queen is worth two knaves, a king is worth a queen and
knave together, and an ace is worth a king and queen together. A king
unguarded is worth less than a queen guarded; a queen is not fully guarded
unless accompanied by three more cards; if guarded by one small card it is
worth a knave guarded. An ace also loses in value by being sole.

A hand to be strong enough for a no-trump declaration should be a king and
ten above the average with all the honours guarded and all the suits
protected. It must be a king and knave or two queens above the average if
there is protection in three suits. It must be an ace or a king and queen
above the average if only two suits are protected. An established black
suit of six or more cards with a guarded king as card of entry is good
enough for no trumps. With three aces no trumps can be declared. Without an
ace, four kings, two queens and a knave are required in order to justify
the declaration. When the dealer has a choice of declarations, a sound
heart make is to be preferred to a doubtful no-trump. Four honours in
hearts are to be preferred to any but a very strong no-trump declaration;
but four aces counting 100 points constitute a no-trump declaration without
exception.

Six hearts should be made trumps and five with two honours unless the hand
is very weak; five hearts with one honour or four hearts with three honours
should be declared if the hand is nearly strong enough for no trumps, also
if the hand is very irregular with one suit missing or five of a black
suit. Six diamonds with one honour, five with three honours or four all
honours should be declared; weaker diamonds should be declared if the suits
are irregular, especially if blank in hearts. Six clubs with three honours
or five with four honours should be declared. Spades are practically only
declared with a weak hand; with only a king in the hand a suit of five
spades should be declared as a defensive measure. With nothing above a ten
a suit of two or three spades can be declared, though even with the weakest
hands a suit of five clubs or of six red cards will probably prove less
expensive.

_Declarations by Dummy._--From the fact that the call has been passed, the
dealer's partner must credit the dealer with less than average strength as
regards the rank of his cards, and probably a slightly increased number of
black cards; he must therefore be more backward in making a high
declaration whenever he can make a sound declaration of less value. On the
other hand, he has not the option of passing the declaration, and may be
driven to declare on less strength because the only alternative is a short
suit of spades. For example, with the hand: Hearts, ace, kv. 2; diamonds,
qn. 9, 7, 6, 3; clubs, kg. 10, 4; spades, 9, 2, the chances are in the
dealer's favour with five trumps, but decidedly against with only two, and
the diamond declaration is to be preferred to the spade. Still, a hand may
be so weak that spades should be declared with two or less, but five clubs
or six diamonds would be preferable with the weakest of hands.

[v.04 p.0530] _Declarations to the Score._--When one's score is over
twenty, club declarations should be made more frequently by the dealer.
Spades should be declared with six at the score of twenty-six and with five
at twenty-eight. When much behind in the score a risky no-trumper such as
one with an established suit of seven or eight cards without a card of
entry, may be declared.

Declaring to the score is often overdone; an ordinary weak no-trump
declaration carries with it small chances of three by tricks unless dummy
holds a no-trump hand.

_Doubling._--Practically the leader only doubles a no-trump declaration
when he holds what is probably an established suit of seven cards or a suit
which can be established with the loss of one trick and he has good cards
of re-entry. Seven cards of a suit including the ace, king and queen make
sound double without any other card of value in the hand, or six cards
including king, queen and knave with two aces in other suits.

Doubling by the third hand is universally understood to mean that the
player has a very strong suit which he can establish. In response to the
double his partner, according to different conventions, leads either a
heart or his own shortest suit as the one most likely to be the third
player's strongest. Under the short suit convention, if the doubler holds
six of a suit headed by the ace, king and queen, it is about an even chance
that his suit will be selected; he should not double with less strength.
Under the heart convention it is not necessary to have such great strength;
with a strong suit of six hearts and good cards of re-entry, enough tricks
will be saved to compensate for the doubled value. A player should
ascertain the convention followed before beginning to play.

Before doubling a suit declaration a player should feel almost certain that
he is as strong as the declarer. The minimum strength to justify the
declaration is generally five trumps, but it may have been made on six. If,
then, a player holds six trumps with an average hand as regards the rank of
his cards, or five trumps with a hand of no-trump strength, it is highly
probable that he is as strong as the declarer. It must be further taken
into account that the act of doubling gives much valuable information to
the dealer, who would otherwise play with the expectation of finding the
trumps evenly distributed; this is counterbalanced when the doubler is on
the left of the declaring hand by the intimation given to his partner to
lead trumps through the strong hand. In this position, then, the player
should double with the strength stated above. When on the declarer's right,
the player should hold much greater strength unless his hand is free from
tenaces. When a spade declaration has been made by dummy, one trump less is
necessary and the doubler need not be on the declarer's left. A spade
declaration by the dealer can be doubled with even less strength. A
declaration can be rather more freely doubled when a single trick undoubled
will take the dealer out, but even in this position the player must be
cautious of informing the dealer that there is a strong hand against him.

_Redoubling._--When a declaration has been doubled, the declarer knows the
minimum that he will find against him; he must be prepared to find
occasionally strength against him considerably exceeding this minimum.
Except in the case of a spade declaration, cases in which redoubling is
justifiable are very rare.

_The Play of the Hand._--In a no-trump declaration the main object is to
bring in a long suit. In selecting the suit to establish, the following are
favourable conditions:--One hand should hold at least five cards of the
suit. The two hands, unless with a sequence of high cards, should hold
between them eight cards of the suit, so as to render it probable that the
suit will be established in three rounds. The hand which contains the
strong suit should be sufficiently strong in cards of re-entry. The suit
should not be so full of possible tenaces as to make it disadvantageous to
open it. As regards the play of the cards in a suit, it is not the object
to make tricks early, but to make all possible tricks. Deep finesses should
be made when there is no other way of stealing a trick. Tricks may be given
away, if by so doing a favourable opening can be made for a finesse. When,
however, it is doubtful with which hand the finesse should be made, it is
better to leave it as late as possible, since the card to be finessed
against may fall, or an adversary may fail, thus disclosing the suit. It is
in general unsound to finesse against a card that must be unguarded. From a
hand short in cards of re-entry, winning cards should not be led out so as
to exhaust the suit from the partner's hand. Even a trick should sometimes
be given away. For instance, if one hand holds seven cards headed by ace,
king, and the other hand hold's only two of the suit, although there is a
fair chance of making seven tricks in the suit, it would often be right to
give the first trick to the adversaries. When one of the adversaries has
shown a long suit, it is frequently possible to prevent its being brought
in by a device, such as holding up a winning card, until the suit is
exhausted from his partner's hand, or playing in other suits so as to give
the player the lead whilst his partner his a card of his suit to return,
and to give the latter the lead when he has no card to return. The dealer
should give as little information as possible as to what he holds in his
own hand, playing frequent false cards. Usually he should play the higher
or highest of a sequence; still, there are positions in which playing the
higher gives more information than the lower; a strict adherence to a rule
in itself assists the adversaries.

With a suit declaration, if there is no chance of letting the weak hand
make a trump by ruffing, it will generally be the dealer's aim to discard
the losing cards in the declaring hand either to high cards or to the cards
of an established suit in the other hand, sometimes after the adverse
trumps have been taken out, but often before, there being no time for
drawing trumps. With no card of any value in a suit in one hand, the lead
should come from that hand, but it is better, if possible, to let the
adversaries open the suit. It is generally useless to lead a moderately
high card from the weaker hand in order to finesse it, when holding no
cards in sequence with it in either hand. Sometimes (especially in
no-trumps) it is the better play to make the weak hand third player. For
instance, with king, 8, 7, 5, 2 in one hand, knave, 4 in the other, the
best way of opening is from the hand that holds five cards.

In a no-trump declaration the opponents of the dealer should endeavour to
find the longest suit in the two hands, or the one most easily established.
With this object the leader should open his best suit. If his partner next
obtains the lead he ought to return the suit, unless he himself has a suit
which he considers better, having due regard to the fact that the first
suit is already partially established. The opponents should employ the same
tactics as the dealer to prevent the latter from bringing in a long suit;
they can use them with special effect when the long suit is in the exposed
hand.

Against no-trumps the leader should not play his winning cards unless he
has a good chance of clearing the suit without help from his partner; in
most cases it is advisable to give away the first trick, especially if he
has no card of re-entry, in order that his partner on gaining the lead may
have a card of the suit to return; but holding ace, king and queen, or ace,
king with seven in the suit, or ace, king, knave, ten with six, the player
may lead out his best. With three honours any two of which are in sequence
(not to the ace) the player should lead the higher of the sequence. He
should lead his highest card from queen, knave, ten; from queen, knave,
nine; from knave, ten, nine; knave, ten, eight, and ten, nine, eight. In
other cases the player should lead a small card; according to the usual
convention, the fourth best. His partner, and also the dealer, can credit
him with three cards higher than the card led, and can often place the
cards of the suit: for instance, the seven is led, dummy holds queen and
eight, playing the queen, the third player holds the nine and smaller
cards; the unseen cards higher than the seven are ace, king, knave and ten
of which the leader must hold three; he cannot hold both knave and ten or
he would have led the knave; he must therefore hold the ace, king and
either knave or ten. The "eleven" rule is as follows: the number of pips in
the card led subtracted from eleven (11-7=4 in the case stated) gives the
number of cards higher than the one led not in the leader's hand; the three
cards seen (queen, nine and eight) leave one for the dealer to hold. The
mental process is no shorter than assigning three out of the unseen cards
to the leader, and by not noting the unseen cards much valuable information
may be missed, as in the illustrative case given.

With a suit declared the best opening lead is a singleton, failing which a
lead from a strong sequence. A lead from a tenace or a guarded king or
queen is to be avoided. Two small cards may be led from, though the lead is
objected to by some. A suit of three small cards of no great strength
should not be opened. In cases of doubt preference should be given to
hearts and to a less extent to diamonds.

To lead up to dummy's weak suits is a valuable rule. The converse, to lead
through strength, must be used with caution, and does not apply to no-trump
declarations. It is not advisable to adopt any of the recent whist methods
of giving information. It is clear that, if the adversaries signal, the
dealer's hand alone is a secret, and he, in addition to his natural
advantage, has the further advantage of better information than either of
the adversaries. The following signals are however, used, and are of great
trick-making value: playing an unnecessarily high card, whether to one's
partner's suit or in discarding in a no-trump declaration, indicates
strength in the suit; in a suit declaration a similar method of play
indicates two only of the suit and a desire to ruff,--it is best used in
the case of a king led by one's partner.

The highest of a sequence led through dummy will frequently tell the third
player that he has a good finesse. The lowest of a sequence led through the
dealer will sometimes explain the position to the third player, at the same
time keeping the dealer in the dark.

When on dummy's left it is futile to finesse against a card not in dummy's
hand. But with ace and knave, if dummy has either king or queen, the knave
should usually be played, partly because the other high card may be in the
leader's hand, partly because, if the finesse fails, the player may still
hold a tenace over dummy. When a player is with any chance of success
trying to establish his long suit, he should keep every card of it if
possible, whether it is a suit already opened or a suit which he wishes his
partner to lead; when, however, the main object of the hand is to establish
one's partner's suit, it is not necessary for a player to keep his own long
suit, and he should pay attention to guarding the other suits. In some
circles a discard from a suit is always understood to indicate strength in
the suit; this convention, while it makes the game easier for inferior
players, frequently causes the player to throw away one of his most
valuable cards.

_Playing to the Score._--At the beginning of the hand the chances are so
great against any particular result, that at the score of love-all the
advantage of getting to any particular score has no appreciable [v.04
p.0531] effect in determining the choice of suit. In the play of the hand,
the advantage of getting to certain points should be borne in mind. The
principal points to be aimed at are 6, 18, and, in a less degree, 22. The
reason is that the scores 24, 12 and 8, which will just take the dealer out
from the respective points, can each be made in a variety of ways, and are
the most common for the dealer to make. The 2 points that take the score
from 4 to 6 are worth 4, or perhaps 5, average points; and the 2 points
that take the score from 6 to 8 are worth 1 point. When approaching game it
is an advantage to make a declaration that may just take the player out,
and, in a smaller degree, one that will not exactly take the adversaries
out. When the score is 24 to 22 against the dealer, hearts and clubs are
half a trick better relatively to diamonds than at the score of love-all.
In the first and second games of the rubber the value of each point scored
for honours is probably about a half of a point scored for tricks--in a
close game rather less, in a one-sided game rather more. In the deciding
game of the rubber, on account of the importance of winning the game, the
value of each point scored for honours sinks to one-third of a point scored
for tricks.

_Other Forms of Bridge._--The following varieties of the game are also
played:--

_Three-handed Bridge._--The three players cut; the one that cuts the lowest
card deals, and takes dummy for one deal: each takes dummy in turn. Dummy's
cards are dealt face downwards, and the dealer declares without seeing
them. If the dealer declares trumps, both adversaries may look at their
hands; doubling and redoubling proceeds as at ordinary bridge, but dummy's
hand is not exposed till the first card has been led. If the dealer passes
the declaration to dummy, his right-hand adversary, who must not have
looked at his own hand, examines dummy's, and declares trumps, not,
however, exposing the hand. The declaration is forced: with three or four
aces _sans atout_ (no trumps) must be declared: in other cases the longest
suit: if suits are equal in length, the strongest, _i.e._ the suit
containing most pips, ace counting eleven, king, queen and knave counting
ten each. If suits are equal in both length and strength, the one in which
the trick has the higher value must be trumps. On the dummy's declaration
the third player can only double before seeing his own cards. When the
first card has been led, dummy's hand is exposed, never before the lead.
The game is 30: the player wins the rubber who is the first to win two
games. Fifty points are scored for each game won, and fifty more for the
rubber. Sometimes three games are played without reference to a rubber,
fifty points being scored for a game won. No tricks score towards game
except those which a player wins in his own deal; the value of tricks won
in other deals is scored above the line with honours, slam and chicane. At
the end of the rubber the totals are added up, and the points won or lost
are adjusted thus. Suppose A is credited with 212, B with 290, and C with
312, then A owes 78 to B and 100 to C; B owes 22 to C.

_Dummy Bridge._--The player who cuts the lowest card takes dummy. Dummy
deals the first hand of all. The player who takes dummy always looks at his
own hand first, when he deals for himself or for dummy; he can either
declare trumps or "leave it" to dummy. Dummy's declaration is compulsory,
as in three-handed bridge. When the dealer deals for dummy, the player on
the dealer's _left_ must not look at his cards till either the dealer has
declared trumps or, the declaration having been left to dummy, his own
partner has led a card. The latter can double, but his partner can only
double without seeing his hand. The dealer can only redouble on his own
hand. When the player of dummy deals for himself, the player on his _right_
hand looks at dummy's hand if the declaration is passed, the positions and
restrictions of his partner and himself being reversed. If the player of
dummy declares from his own hand, the game proceeds as in ordinary bridge,
except that dummy's hand is not looked at till permission to play has been
given. When the player on dummy's right deals, dummy's partner may look at
dummy's hand to decide if he will double, but he may not look at his own
till a card has been led by dummy. In another form of dummy bridge two
hands are exposed whenever dummy's adversaries deal, but the game is
unsuited for many players, as in every other hand the game is one of
double-dummy.

_Misery Bridge._--This is a form of bridge adapted for two players. The
non-dealer has the dummy, whilst the dealer is allowed to strengthen his
hand by discarding four or fewer cards and taking an equal number from the
fourth packet dealt; the rest of the cards in that packet are unused and
remain unseen. A novel and interesting addition to the game is that the
three of clubs (called "Cato") does not rank as a club but can be played to
any trick and win it. The dealer, in addition to his other calls, may
declare "misery" when he has to make less than two tricks.

_Draw- or Two-handed Bridge._--This is the best form of bridge for two
players. Each player has a dummy, which is placed opposite to him; but the
cards are so arranged that they cannot be seen by his opponent, a special
stand being required for the purpose. The dealer makes the declaration or
passes it to his dummy to make by the same rules as in three-handed or
dummy bridge. The objection to this is that, since the opponent does not
see the dealer's dummy, he has no chance of checking an erroneous
declaration. This could be avoided by not allowing the dealer the option of
passing.

_Auction Bridge._--This variety of the game for four players, which adds an
element characteristic of poker, appears to have been suggested about 1904,
but was really introduced at the Bath Club, London, in 1907, and then was
gradually taken up by a wider circle. The laws were settled in August 1908
by a joint committee of the Bath and Portland clubs. The scoring (except as
below), value of suits, and play are as at ordinary bridge, but the variety
consists in the method of declaration, the declaration not being confined
in auction bridge to the dealer or his partner, and the deal being a
disadvantage rather than otherwise. The dealer, having examined his hand,
_must_ declare to win at least one "odd" trick, and then each player in
turn, beginning with the one on the dealer's left, has the right to pass
the previous declaration, or double, or redouble, or overcall by making a
declaration of higher value any number of times till all are satisfied, the
actual play of the combined hands (or what in ordinary bridge would be
dealer and dummy) resting eventually with the partners making the final
declaration; the partner who made the first call (however small) in the
suit finally constituting the trump (or no-trump) plays the hands, the
other being dummy. A declaration of a greater number of tricks in a suit of
lower value, which equals a previous call in value of points (_e.g._ two in
spades as against one in clubs) is "of higher value"; but doubling and
redoubling only affect the score and not the declaration, so that a call of
two diamonds overcalls one no-trump even though this has been doubled. The
scoring in auction bridge has the additional element that when the eventual
player of the two hands wins what was ultimately declared or more, his side
score the full value below the line (as tricks), but if he fails the
opponents score 50 points above the line (as honours) for each under-trick
(_i.e._ trick short of the declaration), or 100 or 200 if doubled or
redoubled, nothing being scored by either side below the line; the loss on
a declaration of one spade is limited, however, to a maximum of 100 points.
A player whose declaration has been doubled and who fulfils his contract,
scores a bonus of 50 points above the line and a further 50 points for each
additional trick beyond his declaration; if there was a redouble and he
wins, he scores double the bonus. The penalty for a revoke (unaffected by a
double) is (1) in the case of the declarer, that his adversaries add 150
above the line; (2) in the case of one of his adversaries, that the
declarer may either add 150 points above the line or may take three tricks
from his opponents and add them to his own; in the latter case such tricks
may assist him to fulfil his contract, but shall not entitle him to any
bonus for a double or redouble. A revoking side may score nothing either
above or below the line except for honours or chicane. As regards the
essential feature of auction bridge, the competitive declaration, it is
impossible here to discuss the intricacies involved. It entails, clearly,
much reliance on a good partner, since the various rounds of bidding enable
good players to draw inferences as to where the cards lie. The game opens
the door to much larger scores than ordinary bridge, and since the end only
comes from scores made below the line, there are obvious ways of prolonging
it at the cost of scores above the line which involve much more of the
gambling element. It by no means follows that the winner of the rubber is
the winner by points, and many players prefer to go for points (_i.e._
above the line) extorted from their opponents rather than for fulfilling a
declaration made by themselves.

AUTHORITIES.--"Hellespont," _Laws and Principles of Bridge_; W. Dalton,
_Saturday Bridge_, containing full bibliography (London, 1906); J. B.
Elwell, _Advanced Bridge_; R. F. Foster, _Bridge Tactics_; "Badsworth,"
_Laws and Principles of Bridge_; E. Bergholt, _Double-Dummy Bridge:
Biritch, or Russian Whist_, pamphlet in Brit. Mus.; W. Dalton, _Auction
Bridge_ (1908).

(W. H. W.*)

BRIDGEBUILDING BROTHERHOOD, a confraternity (_Fratres Pontifices_) that
arose in the south of France during the latter part of the 12th century,
and maintained hospices at the chief fords of the principal rivers, besides
building bridges and looking after ferries. The brotherhood was recognized
by Pope Clement III. in 1189.

BRIDGE-HEAD (Fr. _tête-du-pont_), in fortification, a work designed to
cover the passage of a river by means of fortifications [v.04 p.0532] on
one or both banks. As the process of moving an army over bridges is slow
and complicated, it is usually necessary to secure it from hostile
interruption, and the works constituting the bridge-head must therefore be
sufficiently far advanced to keep the enemy's artillery out of range of the
bridges. In addition, room is required for the troops to form up on the
farther bank. In former days, with short-range weapons, a bridge-head was
often little more than a screen for the bridge itself, but modern
conditions have rendered necessary far greater extension of bridge
defences.

BRIDGEND, a market town in the southern parliamentary division of
Glamorganshire, Wales, on both sides of the river Ogwr (whence its Welsh
name Penybont-ar-Ogwr). Pop. of urban district (1901) 6062. It has a
station 165 m. from London on the South Wales trunk line of the Great
Western railway, and is the junction of the Barry Company's railway to
Barry via Llantwit Major. Bridgend has a good market for agricultural
produce, and is an important centre owing to its being the natural outlet
for the mining valleys of the Llynvi, Garw and the two Ogwr rivers, which
converge about 3 m. north of the town and are connected with it by branch
lines of the Great Western railway. Though without large manufacturing
industries, the town has joinery works, a brass and iron foundry, a tannery
and brewery. There are brick-works and stone quarries, and much lime is
burnt in the neighbourhood. Just outside the town at Angelton and Parc
Gwyllt are the Glamorgan county lunatic asylums.

There was no civil parish of Bridgend previous to 1905, when one was formed
out of portions of the parishes of Newcastle and Coity. Of the castle of
Newcastle, built on the edge of a cliff above the church of that parish,
there remain a courtyard with flanking towers and a fine Norman gateway. At
Coity, about 2 m. distant, there are more extensive ruins of its castle,
originally the seat of the Turbervilles, lords of Coity, but now belonging
to the earls of Dunraven. Coity church, dating from the 14th century, is a
fine cruciform building with central embattled tower in Early Decorated
style.

BRIDGE OF ALLAN, a police burgh of Stirlingshire, Scotland. Pop. (1901)
3240. It lies on the Allan, a left-hand tributary of the Forth, 3 m. N. of
Stirling by the Caledonian railway and by tramway. Built largely on the
well-wooded slopes of Westerton and Airthrey Hill, sheltered by the Ochils
from the north and east winds, and environed by charming scenery, it has a
great reputation as a health resort and watering-place, especially in
winter and spring. There is a pump-room. The chief buildings are the
hydropathic and the Macfarlane museum of fine art and natural history. The
industries include bleaching, dyeing and paper-making. The Strathallan
Gathering, usually held in the neighbourhood, is the most popular athletic
meeting in mid-Scotland. Airthrey Castle, standing in a fine park with a
lake, adjoins the town on the south-east, and just beyond it are the old
church and burying-ground of Logie, beautifully situated at the foot of a
granite spur of the Ochil range.

BRIDGEPORT, a city, a port of entry, and one of the county-seats of
Fairfield county, Connecticut, U.S.A., co-extensive with the town of
Bridgeport, in the S.W. part of the state, on Long Island Sound, at the
mouth of the Pequonnock river; about 18 m. S.W. of New Haven. Pop. (1880)
27,643; (1890) 48,866; (1900) 70,996, of whom 22,281 were foreign-born,
including 5974 from Ireland, 3172 from Hungary, 2854 from Germany, 2755
from England, and 1436 from Italy; (1910) 102,054. Bridgeport is served by
the New York, New Haven & Hartford railway, by lines of coast steamers, and
by steamers to New York City and to Port Jefferson, directly across Long
Island Sound. The harbour, formed by the estuary of the river and Yellow
Mill Pond, an inlet, is excellent. Between the estuary and the pond is a
peninsula, East Bridgeport, in which are some of the largest manufacturing
establishments, and west of the harbour and the river is the main portion
of the city, the wholesale section extending along the bank, the retail
section farther back, and numerous factories along the line of the railway
far to the westward. There are two large parks, Beardsley, in the extreme
north part of the city, and Seaside, west of the harbour entrance and along
the Sound; in the latter are statues of Elias Howe, who built a large
sewing-machine factory here in 1863, and of P.T. Barnum, the showman, who
lived in Bridgeport after 1846 and did much for the city, especially for
East Bridgeport. In Seaside Park there is also a soldiers' and sailors'
monument, and in the vicinity are many fine residences. The principal
buildings are the St Vincent's and Bridgeport hospitals, the Protestant
orphan asylum, the Barnum Institute, occupied by the Bridgeport Scientific
and Historical Society and the Bridgeport Medical Society; and the United
States government building, which contains the post-office and the customs
house.

In 1905 Bridgeport was the principal manufacturing centre in Connecticut,
the capital invested in manufacturing being $49,381,348, and the products
being valued at $44,586,519. The largest industries were the manufacture of
corsets--the product of Bridgeport was 19.9% of the total for the United
States in 1905, Bridgeport being the leading city in this industry--sewing
machines (one of the factories of the Singer Manufacturing Co. is here),
steam-fitting and heating apparatus, cartridges (the factory of the Union
Metallic Cartridge Co. is here), automobiles, brass goods, phonographs and
gramophones, and typewriters. There are also large foundry and machine
shops. Here, too, are the winter headquarters of "Barnum and Bailey's
circus" and of "Buffalo Bill's Wild West Show." Bridgeport is a port of
entry; its imports in 1908 were valued at $656,271. Bridgeport was
originally a part of the township of Stratford. The first settlement here
was made in 1659. It was called Pequonnock until 1695, when its name was
changed to Stratfield. During the War of Independence it was a centre of
privateering. In 1800 the borough of Bridgeport was chartered, and in 1821
the township was incorporated. The city was not chartered until 1836.

See S. Orcutt's _History of the Township of Stratford and the City of
Bridgeport_ (New Haven, 1886).

BRIDGES, ROBERT (1844- ), English poet, born on the 23rd of October 1844,
was educated at Eton and at Corpus Christi College, Oxford, and studied
medicine in London at St Bartholomew's hospital. He was afterwards
assistant physician at the Children's hospital, Great Ormond Street, and
physician at the Great Northern hospital, retiring in 1882. Two years later
he married Mary, daughter of Alfred Waterhouse, R.A. As a poet Robert
Bridges stands rather apart from the current of modern English verse, but
his work has had great influence in a select circle, by its restraint,
purity, precision, and delicacy yet strength of expression; and it embodies
a distinct theory of prosody. His chief critical works are _Milton's
Prosody_ (1893), a volume made up of two earlier essays (1887 and 1889),
and _John Keats, a Critical Essay_ (1895). He maintained that English
prosody depended on the number of "stresses" in a line, not on the number
of syllables, and that poetry should follow the rules of natural speech.
His poetry was privately printed in the first instance, and was slow in
making its way beyond a comparatively small circle of his admirers. His
best work is to be found in his _Shorter Poems_ (1890), and a complete
edition of his _Poetical Works_ (6 vols.) was published in 1898-1905. His
chief volumes are _Prometheus_ (Oxford, 1883, privately printed), a "mask
in the Greek Manner"; _Eros and Psyche_ (1885), a version of Apuleius; _The
Growth of Love_, a series of sixty-nine sonnets printed for private
circulation in 1876 and 1889; _Shorter Poems_ (1890); _Nero_ (1885), a
historical tragedy, the second part of which appeared in 1894; _Achilles in
Scyros_ (1890), a drama; _Palicio_ (1890), a romantic drama in the
Elizabethan manner; _The Return of Ulysses_ (1890), a drama in five acts;
_The Christian Captives_ (1890), a tragedy on the same subject as
Calderon's _El Principe Constante_; _The Humours of the Court_ (1893), a
comedy founded on the same dramatist's _El secreto á voces_ and on Lope de
Vega's _El Perro del hortelano_; _The Feast of Bacchus_ (1889), partly
translated from the _Heauton-Timoroumenos_ of Terence; _Hymns from the
Yattendon Hymnal_ (Oxford, 1899); and _Demeter, a Mask_ (Oxford, 1905).

[v.04 p.0533] BRIDGES. 1. _Definitions and General
Considerations._--Bridges (old forms, _brig_, _brygge_, _brudge_; Dutch,
_brug_; German, _Brücke_; a common Teutonic word) are structures carrying
roadways, waterways or railways across streams, valleys or other roads or
railways, leaving a passage way below. Long bridges of several spans are
often termed "viaducts," and bridges carrying canals are termed
"aqueducts," though this term is sometimes used for waterways which have no
bridge structure. A "culvert" is a bridge of small span giving passage to
drainage. In railway work an "overbridge" is a bridge over the railway, and
an "underbridge" is a bridge carrying the railway. In all countries there
are legal regulations fixing the minimum span and height of such bridges
and the width of roadway to be provided. Ordinarily bridges are fixed
bridges, but there are also movable bridges with machinery for opening a
clear and unobstructed passage way for navigation. Most commonly these are
"swing" or "turning" bridges. "Floating" bridges are roadways carried on
pontoons moored in a stream.

In classical and medieval times bridges were constructed of timber or
masonry, and later of brick or concrete. Then late in the 18th century
wrought iron began to be used, at first in combination with timber or cast
iron. Cast iron was about the same time used for arches, and some of the
early railway bridges were built with cast iron girders. Cast iron is now
only used for arched bridges of moderate span. Wrought iron was used on a
large scale in the suspension road bridges of the early part of the 19th
century. The great girder bridges over the Menai Strait and at Saltash near
Plymouth, erected in the middle of the 19th century, were entirely of
wrought iron, and subsequently wrought iron girder bridges were extensively
used on railways. Since the introduction of mild steel of greater tenacity
and toughness than wrought iron (_i.e._ from 1880 onwards) it has wholly
superseded the latter except for girders of less than 100 ft. span. The
latest change in the material of bridges has been the introduction of
ferro-concrete, armoured concrete, or concrete strengthened with steel bars
for arched bridges. The present article relates chiefly to metallic
bridges. It is only since metal has been used that the great spans of 500
to 1800 ft. now accomplished have been made possible.

2. In a bridge there may be distinguished the _superstructure_ and the
_substructure_. In the former the main supporting member or members may be
an arch ring or arched ribs, suspension chains or ropes, or a pair of
girders, beams or trusses. The bridge flooring rests on the supporting
members, and is of very various types according to the purpose of the
bridge. There is also in large bridges wind-bracing to stiffen the
structure against horizontal forces. The _substructure_ consists of (a) the
piers and end piers or abutments, the former sustaining a vertical load,
and the latter having to resist, in addition, the oblique thrust of an
arch, the pull of a suspension chain, or the thrust of an embankment; and
(b) the foundations below the ground level, which are often difficult and
costly parts of the structure, because the position of a bridge may be
fixed by considerations which preclude the selection of a site naturally
adapted for carrying a heavy structure.

3. _Types of Bridges_.--Bridges may be classed as _arched bridges_, in
which the principal members are in compression; _suspension bridges_, in
which the principal members are in tension; and _girder bridges_, in which
half the components of the principal members are in compression and half in
tension. But there are cases of bridges of mixed type. The choice of the
type to be adopted depends on many and complex considerations:--(1) The
cost, having regard to the materials available. For moderate spans brick,
masonry or concrete can be used without excessive cost, but for longer
spans steel is more economical, and for very long spans its use is
imperative. (2) The importance of securing permanence and small cost of
maintenance and repairs has to be considered. Masonry and concrete are more
durable than metal, and metal than timber. (3) Aesthetic considerations
sometimes have great weight, especially in towns. Masonry bridges are
preferable in appearance to any others, and metal arch bridges are less
objectionable than most forms of girder.

Most commonly the engineer has to attach great importance to the question
of cost, and to design his structure to secure the greatest economy
consistent with the provision of adequate strength. So long as bridge
building was an empirical art, great waste of material was unavoidable. The
development of the theory of structures has been largely directed to
determining the arrangements of material which are most economical,
especially in the superstructure. In the case of bridges of large span the
cost and difficulty of erection are serious, and in such cases facility of
erection becomes a governing consideration in the choice of the type to be
adopted. In many cases the span is fixed by local conditions, such as the
convenient sites for piers, or the requirements of waterway or navigation.
But here also the question of economy must be taken into the reckoning. The
cost of the superstructure increases very much as the span increases, but
the greater the cost of the substructure, the larger the span which is
economical. Broadly, the least costly arrangement is that in which the cost
of the superstructure of a span is equal to that of a pier and foundation.

For masonry, brick or concrete the arch subjected throughout to compression
is the most natural form. The arch ring can be treated as a blockwork
structure composed of rigid voussoirs. The stability of such structures
depends on the position of the line of pressure in relation to the extrados
and intrados of the arch ring. Generally the line of pressure lies within
the middle half of the depth of the arch ring. In finding the line of
pressure some principle such as the principle of least action must be used
in determining the reactions at the crown and springings, and some
assumptions must be made of not certain validity. Hence to give a margin of
safety to cover contingencies not calculable, an excess of material must be
provided. By the introduction of hinges the position of the line of
resistance can be fixed and the stress in the arch ring determined with
less uncertainty. In some recent masonry arched bridges of spans up to 150
ft. built with hinges considerable economy has been obtained.

For an elastic arch of metal there is a more complete theory, but it is
difficult of application, and there remains some uncertainty unless (as is
now commonly done) hinges are introduced at the crown and springings.

In suspension bridges the principal members are in tension, and the
introduction of iron link chains about the end of the 18th century, and
later of wire ropes of still greater tenacity, permitted the construction
of road bridges of this type with spans at that time impossible with any
other system of construction. The suspension bridge dispenses with the
compression member required in girders and with a good deal of the
stiffening required in metal arches. On the other hand, suspension bridges
require lofty towers and massive anchorages. The defect of the suspension
bridge is its flexibility. It can be stiffened by girders and bracing and
is then of mixed type, when it loses much of its advantage in economy.
Nevertheless, the stiffened suspension bridge will probably be the type
adopted in future for very great spans. A bridge on this system has been
projected at New York of 3200 ft. span.

The immense extension of railways since 1830 has involved the construction
of an enormous number of bridges, and most of these are girder bridges, in
which about half the superstructure is in tension and half in compression.
The use of wrought iron and later of mild steel has made the construction
of such bridges very convenient and economical. So far as superstructure is
concerned, more material must be used than for an arch or chain, for the
girder is in a sense a combination of arch and chain. On the other hand, a
girder imposes only a vertical load on its piers and abutments, and not a
horizontal thrust, as in the case of an arch or suspension chain. It is
also easier to erect.

A fundamental difference in girder bridges arises from the mode of support.
In the simplest case the main girders are supported at the ends only, and
if there are several spans they are _discontinuous_ or _independent_. But a
main girder may be supported at two or more points so as to be _continuous_
over two [v.04 p.0534] or more spans. The continuity permits economy of
weight. In a three-span bridge the theoretical advantage of continuity is
about 49% for a dead load and 16% for a live load. The objection to
continuity is that very small alterations of level of the supports due to
settlement of the piers may very greatly alter the distribution of stress,
and render the bridge unsafe. Hence many multiple-span bridges such as the
Hawkesbury, Benares and Chittravatti bridges have been built with
independent spans.

Lastly, some bridges are composed of cantilevers and suspended girders. The
main girder is then virtually a continuous girder hinged at the points of
contrary flexure, so that no ambiguity can arise as to the stresses.

[Illustration: FIG. 1.--Trajan's Bridge.]

Whatever type of bridge is adopted, the engineer has to ascertain the loads
to be carried, and to proportion the parts so that the stresses due to the
loads do not exceed limits found by experience to be safe. In many
countries the limits of working stress in public and railway bridges are
prescribed by law. The development of theory has advanced _pari passu_ with
the demand for bridges of greater strength and span and of more complex
design, and there is now little uncertainty in calculating the stresses in
any of the types of structure now adopted. In the modern metal bridge every
member has a definite function and is subjected to a calculated straining
action. Theory has been the guide in the development of bridge design, and
its trustworthiness is completely recognized. The margin of uncertainty
which must be met by empirical allowances on the side of safety has been
steadily diminished.

The larger the bridge, the more important is economy of material, not only
because the total expenditure is more serious, but because as the span
increases the dead weight of the structure becomes a greater fraction of
the whole load to be supported. In fact, as the span increases a point is
reached at which the dead weight of the superstructure becomes so large
that a limit is imposed to any further increase of span.

[Illustration: FIG. 2.--Bridge of Alcantara.]

HISTORY OF BRIDGE BUILDING

[Illustration: FIG. 3.--Ponte Salario.]

4. _Roman Bridges_.--The first bridge known to have been constructed at
Rome over the Tiber was the timber Pons Sublicius, the bridge defended by
Horatius. The Pons Milvius, now Ponte Molle, was reconstructed in stone by
M. Aemilius Scaurus in 109 B.C., and some portions of the old bridge are
believed to exist in the present structure. The arches vary from 51 to 79
ft. span. The Pons Fabricius (mod. Ponte dei Quattro Capi), of about 62
B.C., is practically intact; and the Pons Cestius, built probably in 46
B.C., retains much of the original masonry. The Pons Aelius, built by
Hadrian A.D. 134 and repaired by Pope Nicholas II. and Clement IX., is now
the bridge of St Angelo. It had eight arches, the greatest span being 62
ft.[1] Dio Cassius mentions a bridge, possibly 3000 to 4000 ft. in length,
built by Trajan over the Danube in A.D. 104. Some piers are said still to
exist. A bas-relief on the Trajan column shows this bridge with masonry
piers and timber arches, but the representation is probably conventional
(fig. 1). Trajan also constructed the bridge of Alcantara in Spain (fig.
2), of a total length of 670 ft., at 210 ft. above the stream. This had six
arches and was built of stone blocks without cement. The bridge of Narses,
built in the 6th century (fig. 3), carried the Via Salaria over the Anio.
It was destroyed in 1867, during the approach of Garibaldi to Rome. It had
a fortification such as became usual in later bridges for defence or for
the enforcement of tolls. The great lines of aqueducts built by Roman
engineers, and dating from 300 B.C. onwards, where they are carried above
ground, are arched bridge structures of remarkable magnitude (see
AQUEDUCTS, § _Roman_). They are generally of brick and concrete.

[Illustration: FIG. 4.--First Span of Schaffhausen Bridge.]

5. _Medieval and other Early Bridges_.--Bridges with stone piers and timber
superstructures were no doubt constructed from Roman times onward, but they
have perished. Fig. 4 shows a timber bridge erected by the brothers
Grubenmann at Schaffhausen about the middle of the 18th century. It had
spans of 172 and 193 ft., and may be taken as a representative type of
bridges of this kind. The Wittingen bridge by the same engineers had a span
of 390 ft., probably the longest timber [v.04 p.0535] span ever
constructed. Of stone bridges in Great Britain, the earliest were the
cyclopean bridges still existing on Dartmoor, consisting of stone piers
bridged by stone slabs. The bridge over the East Dart near Tavistock had
three piers, with slabs 15 ft. by 6 ft. (Smiles, _Lives of the Engineers,_
ii. 43). It is reputed to have lasted for 2000 years.

[Illustration: FIG. 5.--Crowland Bridge.]

The curious bridge at Crowland near Peterborough (fig. 5) which now spans
roadways, the streams which formerly flowed under it having been diverted,
is one of the earliest known stone bridges in England. It is referred to in
a charter of the year 943. It was probably built by the abbots. The first
bridges over the Thames at London were no doubt of timber. William of
Malmesbury mentions the existence of a bridge in 994. J. Stow (_Survey of
the Cities of London and Westminster_) describes the building of the first
stone bridge commonly called Old London Bridge: "About the year 1176, the
stone bridge was begun to be founded by Peter of Colechurch, near unto the
bridge of timber, but more towards the west." It carried timber houses
(fig. 6) which were frequently burned down, yet the main structure existed
till the beginning of the 19th century. The span of the arches ranged from
10 to 33 ft., and the total waterway was only 337 ft. The waterway of the
present London Bridge is 690 ft., and the removal of the obstruction caused
by the old bridge caused a lowering of the low-water level by 5 ft., and a
considerable deepening of the river-bed. (See Smiles, _Lives of the
Engineers_, "Rennie.")

[Illustration: FIG. 6.--Old London Bridge, A.D. 1600. From a Drawing in the
Pepysian Library Magdalene College, Cambridge.

From J. R Green's _A Short History of the English People_, by permission of
Macmillan & Co., Ltd.]

The architects of the Renaissance showed great boldness in their designs. A
granite arch built in 1377 over the Adda at Trezzo had a span at low water
of 251 ft. This noble bridge was destroyed for military reasons by
Carmagnola in 1416. The Rialto bridge at Venice, with a span of 91 ft., was
built in 1588 by Antonio da Ponte. Fig. 7 shows the beautiful Ponte dellà
Trinità erected at Florence in 1566 from the design of B. Ammanati.

6. _Modern Bridges._--(a) _Timber._--In England timber bridges of
considerable span, either braced trusses or laminated arches (_i.e._ arches
of planks bolted together), were built for some of the earlier railways,
particularly the Great Western and the Manchester, Sheffield &
Lincolnshire. They have mostly been replaced, decay having taken place at
the joints. Timber bridges of large span were constructed in America
between the end of the 18th and the middle of the 19th century. The
Amoskeag bridge over the Merrimac at Manchester, N.H., U.S.A., built in
1792, had 6 spans of 92 ft. The Bellows Falls bridge over the Connecticut
(built 1785-1792) had 2 spans of 184 ft. The singular Colossus bridge,
built in 1812 over the Schuylkill, a kind of flat arched truss, had a span
of 340 ft. Some of these timber bridges are said to have lasted ninety
years with ordinary repairs, but they were road bridges not heavily loaded.
From 1840, trusses, chiefly of timber but with wrought-iron tension-rods
and cast-iron shoes, were adopted in America. The Howe truss of 1830 and
the Pratt truss of 1844 are examples. The Howe truss had timber chords and
a lattice of timber struts, with vertical iron ties. In the Pratt truss the
struts were vertical and the ties inclined. Down to 1850 such bridges were
generally limited to 150 ft. span. The timber was white pine. As railway
loads increased and greater spans were demanded, the Howe truss was
stiffened by timber arches on each side of each girder. Such a composite
structure is, however, fundamentally defective, the distribution of loading
to the two independent systems being indeterminate. Remarkably high timber
piers were built. The Genesee viaduct, 800 ft. in length, built in
1851-1852 in 10 spans, had timber trestle piers 190 ft. in height. (See
Mosse, "American Timber Bridges," _Proc. Inst. C.E._ xxii. p. 305, and for
more modern examples, cxlii. p. 409; and clv. p. 382; Cooper, "American
Railroad Bridges," _Trans. Am. Soc. C.E._ vol. xxi pp. 1-28.) These timber
framed structures served as models for the earlier metal trusses which
began to be used soon after 1850, and which, except in a few localities
where iron is costly, have quite superseded them.

[Illustration: FIG. 7.--Ponte della Trinità, Florence.]

7. (b) _Masonry._--The present London Bridge, begun in 1824 and completed
in 1831, is as fine an example of a masonry arch structure as can be found
(figs. 8 and 9). The design was made by John Rennie the elder, and the
acting engineer was his son, Sir John Rennie. The semi-elliptical shape of
the arches the variation of span, the slight curvature of the roadway, and
the simple yet bold architectural details, combine to make it a singularly
beautiful bridge. The centre arch has a span of 152 ft., and rises 29 ft. 6
in above Trinity high-water mark; the arches on each side of the centre
have a span of 140 ft. and the abutment arches 130 ft. The total length of
the bridge is 1005 ft., its width from outside to outside 56 ft., and
height above low [v.04 p.0536] water 60 ft. The two centre piers are 24 ft.
thick, the exterior stones are granite, the interior, half Bramley Fall and
half from Painshaw, Derbyshire. The voussoirs of the centre arch (all of
granite) are 4 ft. 9 in. deep at the crown, and increase to not less than 9
ft. at the springing. The general depth at which the foundations are laid
is about 29 ft. 6 in. below low water. The total cost was £1,458,311, but
the contractor's tender for the bridge alone was £425,081.

[Illustration: FIG. 8.--London New Bridge.]

Since 1867 it had been recognized that London Bridge was inadequate to
carry the traffic passing over it, and a scheme for widening it was adopted
in 1900. This was carried out in 1902-1904, the footways being carried on
granite corbels, on which are mounted cornices and open parapets. The width
between parapets is now 65 ft., giving a roadway of 35 ft. and two footways
of 15 ft. each. The architect was Andrew Murray and the engineer, G. E. W.
Cruttwell. (Cole, _Proc. Inst. C.E._ clxi. p. 290.)

The largest masonry arch is the Adolphe bridge in Luxemburg, erected in
1900-1903. This has a span of 278 ft., 138 ft. rise above the river, and
102 ft. from foundation to crown. The thickness of the arch is 4 ft. 8 in.
at the crown and 7 ft. 2 in. where it joins the spandrel masonry. The
roadway is 52 ft. 6 in. wide. The bridge is not continuous in width, there
are arch rings on each face, each 16.4 ft. wide with a space between of
19.7 ft. This space is filled with a flooring of reinforced concrete,
resting on the two arches, and carrying the central roadway. By the method
adopted the total masonry has been reduced one-third. One centering was
used for the two arch rings, supported on dwarf walls which formed a
slipway, along which it was moved after the first was built.

[Illustration: FIG. 9.--Half Elevation and Half Section of Arch of London
Bridge.]

Till near the end of the 19th century bridges of masonry or brickwork were
so constructed that they had to be treated as rigid blockwork structures.
The stability of such structures depends on the position of the line of
pressure relatively to the intrados and extrados of the arch ring.
Generally, so far as could be ascertained, the line of pressure lies within
the middle half of the depth of the voussoirs. In finding the abutment
reactions some principle such as the principle of least action must be
used, and some assumptions of doubtful validity made. But if hinges are
introduced at crown and springings, the calculation of the stresses in the
arch ring becomes simple, as the line of pressures must pass through the
hinges. Such hinges have been used not only for metal arches, but in a
modified form for masonry and concrete arches. Three cases therefore arise:
(a) The arch is rigid at crown and springings; (b) the arch is two-hinged
(hinges at springings); (c) the arch is three-hinged (hinges at crown and
springings). For an elementary account of the theory of arches, hinged or
not, reference may be made to a paper by H. M. Martin (_Proc. Inst. C. E._
vol. xciii. p. 462); and for that of the elastic arch, to a paper by
A.E.Young (_Proc. Inst. C.E._ vol. cxxxi. p. 323).

In Germany and America two- and three-hinged arches of masonry and concrete
have been built, up to 150 ft. span, with much economy, and the
calculations being simple, an engineer can venture to work closely to the
dimensions required by theory. For hinges, Leibbrand, of Stuttgart, uses
sheets of lead about 1 in. thick extending over the middle third of the
depth of the voussoir joints, the rest of the joints being left open. As
the lead is plastic this construction is virtually an articulation. If the
pressure on the lead is uniformly varying, the centre of pressure must be
within the middle third of the width of the lead; that is, it cannot
deviate from the centre of the voussoir joint by more than one-eighteenth
of its depth. In any case the position of the line of pressures is confined
at the lead articulations within very narrow limits, and ambiguity as to
the stresses is greatly diminished. The restricted area on which the
pressure acts at the lead joints involves greater intensity of stress than
has been usual in arched bridges. In the Württemberg hinged arches a limit
of stress of 110 tons per sq. ft. was allowed, while in the unhinged arches
at Cologne and Coblentz the limit was 50 to 60 tons per sq. ft. (_Annales
des Fonts et Chaussées_, 1891). At Rechtenstein a bridge of two concrete
arches has been constructed, span 75½ ft., with lead articulations: width
of arch 11 ft.; depth of arch at crown and springing 2.1 and 2.96 ft.
respectively. The stresses were calculated to be 15, 17 and 12 tons per sq.
ft. at crown, joint of rupture, and springing respectively. At Cincinnati a
concrete arch of 70 ft. span has been built, with a rise of 10 ft. The
concrete is reinforced by eleven 9-in. steel-rolled joists, spaced 3 ft.
apart and supported by a cross-channel joist at each springing. The arch is
15 in. thick at the crown and 4 ft. at the abutments. The concrete
consisted of 1 cement, 2 sand and 3 to 4 broken stone. An important series
of experiments on the strength of masonry, brick and concrete structures
will be found in the _Zeitschr. des österreichen Ing. und Arch. Vereines_
(1895).

The thermal coefficient of expansion of steel and concrete is nearly the
same, otherwise changes of temperature would cause shearing stress at the
junction of the two materials. If the two materials are disposed
symmetrically, the amount of load carried by each would be in direct
proportion to the coefficient of elasticity and inversely as the moment of
inertia of the cross section. But it is usual in many cases to provide a
sufficient section of steel to carry all the tension. For concrete the
coefficient of elasticity E varies with the amount of stress and diminishes
as the ratio of sand and stone to cement increases. Its value is generally
taken at 1,500,000 to 3,000,000 lb per sq. in. For steel E = 28,000,000 to
30,000,000, or on the average about twelve times its value for concrete.
The maximum compressive working stress on the concrete may be 500 lb per
sq. in., the tensile working stress 50 lb per sq. in., and the working
shearing stress 75 lb per sq. in. The tensile stress on the steel may be
16,000 lb per sq. in. The amount of steel in the structure may vary from
0.75 to 1.5%. The concrete not only affords much of the strength to resist
compression, but effectively protects the steel from corrosion.

8. (c) _Suspension Bridges._--A suspension bridge consists of two or more
chains, constructed of links connected by pins, or of twisted wire strands,
or of wires laid parallel. The chains pass over lofty piers on which they
usually rest on saddles carried by rollers, and are led down on either side
to anchorages in rock chambers. A level platform is hung from the chains by
suspension rods. In the suspension bridge iron or steel can be used in its
strongest form, namely hard-drawn wire. Iron suspension bridges began to be
used at the end of the 18th century for road bridges with spans
unattainable at that time in any other system. In 1819 T. Telford began the
construction of the Menai bridge (fig. 10), the span being 570 ft. and the
dip 43 ft. This bridge suffered some injury in a storm, but it is still in
good condition and one of the most graceful of bridges. Other bridges built
soon after were the Fribourg bridge of 870 ft. span, the Hammersmith bridge
of 422 ft. span, and the Pest bridge of 666 ft. span. The merit of the
simple suspension bridge is its cheapness, and its defect is its
flexibility. This last becomes less [v.04 p.0537] serious as the dead
weight of the structure becomes large in proportion to the live or
temporary load. It is, therefore, a type specially suited for great spans.
Some suspension bridges have broken down in consequence of the oscillations
produced by bodies of men marching in step. In 1850 a suspension bridge at
Angers gave way when 487 soldiers were marching over it, and 226 were
killed.

[Illustration: FIG. 10.--Menai Suspension Bridge.]

To obtain greater stiffness various plans have been adopted. In the Ordish
system a certain number of intermediate points in the span are supported by
oblique chains, on which girders rest. The Ordish bridge built at Prague in
1868 had oblique chains supporting the stiffening girders at intermediate
points of the span. A curved chain supported the oblique chains and kept
them straight. In 1860 a bridge was erected over the Danube canal at
Vienna, of 264 ft. span which had two parallel chains one above the other
and 4 ft. apart on each side of the bridge. The chains of each pair were
connected by bracing so that they formed a stiff inverted arch resisting
deformation under unequal loading. The bridge carried a railway, but it
proved weak owing to errors of calculation, and it was taken down in 1884.
The principle was sound and has been proposed at various times. About 1850
it was perceived that a bridge stiff enough to carry railway trains could
be constructed by combining supporting chains with stiffening girders
suspended from them. W. J. M. Rankine proved (_Applied Mechanics_, p. 370)
that the necessary strength of a stiffening girder would be only
one-seventh part of that of an independent girder of the same span as the
bridge, suited to carry the same moving load (not including the dead weight
of the girder which is supported by the chain). (See "Suspension Bridge
with Stiffened Roadway," by Sir G. Airy, and the discussion, _Proc. Inst,
C.E._, 1867, xxvi. p. 258; also "Suspension Bridges with Stiffening
Girders," by Max am Ende, _Proc. Inst. C.E._ cxxxvii. p. 306.)

[Illustration: FIG. 11.--Niagara Suspension Bridge.]

The most remarkable bridge constructed on this system was the Niagara
bridge built by J. A. Roebling in 1852-1855 (fig. 11). The span was 821
ft., much the largest of any railway bridge at that time, and the height
above the river 245 ft. There were four suspension cables, each 10 in. in
diameter; each was composed of seven strands, containing 520 parallel
wires, or 3640 wires in each cable. Each cable was carried on a separate
saddle on rollers on each pier. The stiffening girder, constructed chiefly
of timber, was a box-shaped braced girder 18 ft. deep and 25 ft. wide,
carrying the railway on top and a roadway within. After various repairs and
strengthenings, including the replacement of the timber girder by an iron
one in 1880, this bridge in 1896-1897 was taken down and a steel arch built
in its place. It was not strong enough to deal with the increasing weight
of railway traffic. In 1836 I. K. Brunei constructed the towers and
abutments for a suspension bridge of 702 ft. span at Clifton over the Avon,
but the project was not then carried further; in 1860, however, the link
chains of the Hungerford suspension bridge which was being taken down were
available at small cost, and these were used to complete the bridge. There
are three chains on each side, of one and two links alternately, and these
support wrought iron stiffening girders. There are wrought iron saddles and
steel rollers on the piers. At 196 ft. on either side from the towers the
chains are carried over similar saddles without rollers, and thence at 45°
with the horizontal down to the anchorages. Each chain has an anchor plate
5 ft. by 6 ft. The links are 24 ft. long at the centre of the bridge, and
longer as they are more inclined, so that their horizontal projection is 24
ft. The chains are so arranged that there is a suspending rod at each 8
ft., attached at the joint of one of the three chains. For erection a
suspended platform was constructed on eight wire ropes, on which the chains
were laid out and connected. Another wire rope with a travelling carriage
took out the links. The sectional area of the chains is 481 sq. in. at the
piers and 440 sq. in. at the centre. The two stiffening girders are plate
girders 3 ft. deep with flanges of 11 sq. in. area. In addition, the hand
railing on each side forms a girder 4 ft. 9 in. deep, with flanges 4½ sq.
in. area.

[Illustration: FIG. 12.--Williamsburg Suspension Bridge.]

Of later bridges of great span, perhaps the bridges over the East river at
New York are the most remarkable. The Brooklyn bridge, begun in 1872, has a
centre span of 1595½ and side spans of 930 ft. The Brooklyn approach being
971 ft., and the New York approach 1562½ ft., the total length of the
bridge is 5989 ft. There are four cables which carry a promenade, a roadway
and an electric railway. The stiffening girders of the main span are 40 ft.
deep and 67 ft. apart. The saddles for the chains are 329 ft. above high
water. The cables are 15¾ in. in diameter. Each cable has 19 strands of 278
parallel steel wires, 7 B.W.G. Each wire is taken separately across the
river and its length adjusted. Roebling preferred parallel wires as 10 %
stronger than twisted wires. Each strand when made up and clamped was
lowered to its position. The Williamsburg bridge (fig. 12), begun in 1897
and opened for traffic in 1903, has a span of 1600 ft., a versed sine of
176 ft., and a width of 118 ft. It has two decks, and carries two elevated
railway tracks, four electric tramcar lines, two carriageways, two footways
and two [v.04 p.0538] bicycle paths. There are four cables, one on each
side of the two main trusses or stiffening girders. These girders are
supported by the cables over the centre span but not in the side spans.
Intermediate piers support the trusses in the side spans. The cables are
18¾ in. in diameter; each weighs about 1116 tons, and has a nominal
breaking strength of 22,320 tons, the actual breaking strength being
probably greater. The saddles are 332 ft. above the water. The four cables
support a dead load of 7140 tons and a live load of 4017 tons. Each cable
is composed of 37 strands of 208 wires, or 7696 parallel steel wires, No. 8
B.W.G., or about 3/16 in. in diameter. The wire was required to have a
tensile strength of 89 tons per sq. in., and 2½% elongation in 5 ft. and 5%
in 8 in. Cast steel clamps hold the cable together, and to these the
suspending rods are attached. The cables are wrapped in cotton duck soaked
in oxidized oil and varnish, and are sheathed in sheet iron. A later
bridge, the Manhattan, is designed to carry four railway tracks and four
tramway lines, with a wide roadway and footpaths, supported by cables 21¼
in. in diameter, each composed of 9472 galvanized steel wires 3/16 in. in
diameter.

[Illustration: FIG. 13.--Tower Bridge, London.]

The Tower Bridge, London (fig. 13), is a suspension bridge with a secondary
bascule bridge in the centre span to permit the passage of ships. Two main
towers in the river and two towers on the shore abutments carry the
suspension chains. The opening bridge between the river towers consists of
two leaves or bascules, pivoted near the faces of the piers and rotating in
a vertical plane. When raised, the width of 200 ft. between the main river
piers is unobstructed up to the high-level foot-bridge, which is 141 ft.
above Trinity H.W. The clear width of the two shore spans is 270 ft. The
total length of the bridge is 940 ft., and that of the approaches 1260 ft.
on the north and 780 ft. on the south. The width of the bridge between
parapets is 60 ft., except across the centre span, where it is 49 ft. The
main towers consist of a skeleton of steel, enclosed in a facing of granite
and Portland stone, backed with brickwork. There are two high-level
footways for use when the bascules are raised, the main girders of which
are of the cantilever and suspended girder type. The cantilevers are fixed
to the shore side of the towers. The middle girders are 120 ft. in length
and attached to the cantilevers by links. The main suspension chains are
carried across the centre span in the form of horizontal ties resting on
the high-level footway girders. These ties are jointed to the hanging
chains by pins 20 in. in diameter with a ring in halves surrounding it 5
in. thick. One half ring is rigidly attached to the tie and one to the
hanging chain, so that the wear due to any movement is distributed over the
length of the pin. A rocker bearing under these pins transmits the load at
the joint to the steel columns of the towers. The abutment towers are
similar to the river towers. On the abutment towers the chains are
connected by horizontal links, carried on rockers, to anchor ties. The
suspension chains are constructed in the form of braced girders, so that
they are stiff against unsymmetrical loading. Each chain over a shore span
consists of two segments, the longer attached to the tie at the top of the
river tower, the shorter to the link at the top of the abutment tower, and
the two jointed together at the lowest point. Transverse girders are hung
from the chains at distances of 18 ft. There are fifteen main transverse
girders to each shore span, with nine longitudinal girders between each
pair. The trough flooring, 3/8 in. thick and 6 in. deep, is riveted to the
longitudinals. The anchor ties are connected to girders embedded in large
concrete blocks in the foundations of the approach viaducts.

The two bascules are each constructed with four main girders. Over the
river these are lattice girders, with transverse girders 12 ft. apart, and
longitudinal and subsidiary transverse girders dividing the floor into
rectangles 3 ft. by 3½ ft. covered with buckled plates. The roadway is of
pine blocks dowelled. The bascules rotate through an angle of 82°, and
their rear ends in the bascule chambers of the piers carry 365 tons of
counterweight, the total weight of each being 1070 tons. They rotate on
steel shafts 21 in. in diameter and 48 ft. long, and the bascules can be
lifted or lowered in one minute, but usually the time taken is one and a
half minutes. They are worked by hydraulic machinery.

9. (d) _Iron and Steel Girder Bridges._--The main supporting members are
two or more horizontal beams, girders or trusses. The girders carry a floor
or platform either on top (_deck_ bridges) or near the bottom (_through_
bridges). The platform is variously constructed. For railway bridges it
commonly consists of cross girders, attached to or resting on the main
girders, and longitudinal rail girders or stringers carried by the cross
girders and directly supporting the sleepers and rails. For spans over 75
ft., expansion due to change of temperature is provided for by carrying one
end of each chain girder on rollers placed between the bearing-plate on the
girder and the bed-plate on the pier or abutment.

Fig. 14 shows the roller bed of a girder of the Kuilenburg bridge of 490
ft. span. It will be seen that the girder directly rests on a cylindrical
pin or rocker so placed as to distribute the load uniformly to all the
rollers. The pressure on the rollers is limited to about p = 600 d in lb
per in. length of roller, where d is the diameter of the roller in inches.

[Illustration: FIG. 14.--Roller Bed of a Girder.]

In the girders of bridges the horizontal girder is almost exclusively
subjected to vertical loading forces. Investigation of the internal
stresses, which balance the external forces, shows that most of the
material should be arranged in a top flange, boom or chord, subjected to
compression, and a bottom flange or chord, subjected to tension. (See
STRENGTH OF MATERIALS.) Connecting the flanges is a vertical web which may
be a solid plate or a system of bracing bars. In any case, though the exact
form of cross section of girders varies very much, it is virtually an I
section (fig. 15). The function of the flanges is to resist a horizontal
tension and compression distributed practically uniformly on their cross
sections. The web resists forces equivalent [v.04 p.0539] to a shear on
vertical and horizontal planes. The inclined tensions and compressions in
the bars of a braced web are equivalent to this shear. The horizontal
stresses in the flanges are greatest at the centre of a span. The stresses
in the web are greatest at the ends of the span. In the most numerous cases
the flanges or chords are parallel. But girders may have curved chords and
then the stresses in the web are diminished.

[Illustration: FIG. 15.--Flanged Girder.]

At first girders had solid or plate webs, but for spans over 100 ft. the
web always now consists of bracing bars. In some girder bridges the members
are connected entirely by riveting, in others the principal members are
connected by pin joints. The pin system of connexion used in the Chepstow,
Saltash, Newark Dyke and other early English bridges is now rarely used in
Europe. But it is so commonly used in America as to be regarded as a
distinctive American feature. With pin connexions some weight is saved in
the girders, and erection is a little easier. In early pin bridges
insufficient bearing area was allowed between the pins and parts connected,
and they worked loose. In some cases riveted covers had to be substituted
for the pins. The proportions are now better understood. Nevertheless the
tendency is to use riveted connexions in preference to pins, and in any
case to use pins for tension members only.

On the first English railways cast iron girder bridges for spans of 20 to
66 ft. were used, and in some cases these were trussed with wrought iron.
When in 1845 the plans for carrying the Chester and Holyhead railway over
the Menai Straits were considered, the conditions imposed by the admiralty
in the interests of navigation involved the adoption of a new type of
bridge. There was an idea of using suspension chains combined with a
girder, and in fact the tower piers were built so as to accommodate chains.
But the theory of such a combined structure could not be formulated at that
time, and it was proved, partly by experiment, that a simple tubular girder
of wrought iron was strong enough to carry the railway. The Britannia
bridge (fig. 16) has two spans of 460 and two of 230 ft. at 104 ft. above
high water. It consists of a pair of tubular girders with solid or plate
sides stiffened by angle irons, one line of rails passing through each
tube. Each girder is 1511 ft. long and weighs 4680 tons. In cross section
(fig. 17), it is 15 ft. wide and varies in depth from 23 ft. at the ends to
30 ft. at the centre. Partly to counteract any tendency to buckling under
compression and partly for convenience in assembling a great mass of
plates, the top and bottom were made cellular, the cells being just large
enough to permit passage for painting. The total area of the cellular top
flange of the large-span girders is 648 sq. in., and of the bottom 585 sq.
in. As no scaffolding could be used for the centre spans, the girders were
built on shore, floated out and raised by hydraulic presses. The credit for
the success of the Conway and Britannia bridges must be divided between the
engineers. Robert Stephenson and William Fairbairn, and Eaton Hodgkinson,
who assisted in the experimental tests and in formulating the imperfect
theory then available. The Conway bridge was first completed, and the first
train passed through the Britannia bridge in 1850. Though each girder has
been made continuous over the four spans it has not quite the proportions
over the piers which a continuous girder should have, and must be regarded
as an imperfectly continuous girder. The spans were in fact designed as
independent girders, the advantage of continuity being at that time
imperfectly known. The vertical sides of the girders are stiffened so that
they amount to 40% of the whole weight. This was partly necessary to meet
the uncertain conditions in floating when the distribution of supporting
forces was unknown and there were chances of distortion.

[Illustration: FIG. 16.--Britannia Bridge.]

[Illustration: FIG. 17.--Britannia Bridge (Cross Section of Tubular
Girder).]

Wrought iron and, later, steel plate web girders were largely used for
railway bridges in England after the construction of the Conway and Menai
bridges, and it was in the discussions arising during their design that the
proper function of the vertical web between the top and bottom flanges of a
girder first came to be understood. The proportion of depth to span in the
Britannia bridge was 1/16. But so far as the flanges are concerned the
stress [v.04 p.0540] to be resisted varies inversely as the depth of the
girder. It would be economical, therefore, to make the girder very deep.
This, however, involves a much heavier web, and therefore for any type of
girder there must be a ratio of depth to span which is most economical. In
the case of the plate web there must be a considerable excess of material,
partly to stiffen it against buckling and partly because an excess of
thickness must be provided to reduce the effect of corrosion. It was soon
found that with plate webs the ratio of depth to span could not be
economically increased beyond 1/15 to 1/12. On the other hand a framed or
braced web afforded opportunity for much better arrangement of material,
and it very soon became apparent that open web or lattice or braced girders
were more economical of material than solid web girders, except for small
spans. In America such girders were used from the first and naturally
followed the general design of the earlier timber bridges. Now plate web
girders are only used for spans of less than 100 ft.

Three types of bracing for the web very early developed--the Warren type in
which the bracing bars form equilateral triangles, the Whipple Murphy in
which the struts are vertical and the ties inclined, and the lattice in
which both struts and ties are inclined at equal angles, usually 45° with
the horizontal. The earliest published theoretical investigations of the
stresses in bracing bars were perhaps those in the paper by W.T. Doyne and
W.B. Blood (_Proc. Inst. C.E._, 1851, xi. p. 1), and the paper by J.
Barton, "On the economic distribution of material in the sides of wrought
iron beams" (_Proc. Inst. C.E._, 1855, xiv. p. 443).

[Illustration: FIG. 18.--Span of Saltash Bridge.]

The Boyne bridge, constructed by Barton in Ireland, in 1854-1855, was a
remarkable example of the confidence with which engineers began to apply
theory in design. It was a bridge for two lines of railway with lattice
girders continuous over three spans. The centre span was 264 ft., and the
side spans 138 ft. 8 in.; depth 22 ft. 6 in. Not only were the bracing bars
designed to calculated stresses, and the continuity of the girders taken
into account, but the validity of the calculations was tested by a
verification on the actual bridge of the position of the points of contrary
flexure of the centre span. At the calculated position of one of the points
of contrary flexure all the rivets of the top boom were cut out, and by
lowering the end of the girder over the side span one inch, the joint was
opened 1/32 in. Then the rivets were cut out similarly at the other point
of contrary flexure and the joint opened. The girder held its position with
both joints severed, proving that, as should be the case, there was no
stress in the boom where the bending moment changes sign.

[Illustration: FIG. 19.--Newark Dyke Bridge and Section of Newark Dyke
Bridge.]

By curving the top boom of a girder to form an arch and the bottom boom to
form a suspension chain, the need of web except for non-uniform loading is
obviated. I.K. Brunel adopted this principle for the Saltash bridge near
Plymouth, built soon after the Britannia bridge. It has two spans of 455
ft. and seventeen smaller spans, the roadway being 100 ft. above high
water. The top boom of each girder is an elliptical wrought iron tube 17
ft. wide by 12 ft. deep. The lower boom is a pair of chains, of
wrought-iron links, 14 in each chain, of 7 in. by 1 in. section, the links
being connected by pins. The suspending rods and cross bracing are very
light. The depth of the girder at the centre is about one-eighth of the
span.

[Illustration: FIG. 20.--Fink Truss.]

In both England and America in early braced bridges cast iron, generally in
the form of tubes circular or octagonal in section, was used for
compression members, and wrought iron for the tension members. Fig. 19
shows the Newark Dyke bridge on the Great Northern railway over the Trent.
It was a pin-jointed Warren girder bridge erected from designs by C.M. Wild
in 1851-1853. The span between supports was 259 ft., the clear span 240½
ft.; depth between joint pins 16 ft. There were four girders, two to each
line of way. The top flange consisted of cast iron hollow castings butted
end to end, and the struts were of cast iron. The lower flange and ties
were flat wrought iron links. This bridge has now been replaced by a
stronger bridge to carry the greater loads imposed by modern traffic. Fig.
20 shows a Fink truss, a characteristic early American type, with cast iron
compression and wrought iron tension members. The bridge is a deck bridge,
the railway being carried on top. The transfer of the loads to the ends of
the bridge by [v.04 p.0541] long ties is uneconomical, and this type has
disappeared. The Warren type, either with two sets of bracing bars or with
intermediate verticals, affords convenient means of supporting the floor
girders. In 1869 a bridge of 390 ft. span was built on this system at
Louisville.

Amongst remarkable American girder bridges may be mentioned the Ohio bridge
on the Cincinnati & Covington railway, which is probably the largest girder
span constructed. The centre span is 550 ft. and the side spans 490
ft.--centre to centre of piers. The girders are independent polygonal
girders. The centre girder has a length of 545 ft. and a depth of 84 ft.
between pin centres. It is 67 ft. between parapets, and carries two lines
of railway, two carriageways, and two footways. The cross girders,
stringers and wind-bracing are wrought iron, the rest of mild steel. The
bridge was constructed in 1888 by the Phoenix Bridge Company, and was
erected on staging. The total weight of iron and steel in three spans was
about 5000 tons.

[Illustration: FIG. 21.--Typical Cantilever Bridge.]

[Illustration: FIG. 22.]

10. (e) _Cantilever Bridges._--It has been stated that if in a girder
bridge of three or more spans, the girders were made continuous there would
be an important economy of material, but that the danger of settlement of
the supports, which would seriously alter the points of contrary flexure or
points where the bending moment changes sign, and therefore the magnitude
and distribution of the stresses, generally prevents the adoption of
continuity. If, however, hinges or joints are introduced at the points of
contrary flexure, they become necessarily points where the bending moment
is zero and ambiguity as to the stresses vanishes. The exceptional local
conditions at the site of the Forth bridge led to the adoption there of the
cantilever system, till then little considered. Now it is well understood
that in many positions this system is the simplest and most economical
method of bridging. It is available for spans greater than those
practicable with independent girders; in fact, on this system the spans are
virtually reduced to smaller spans so far as the stresses are concerned.
There is another advantage which in many cases is of the highest
importance. The cantilevers can be built out from the piers, member by
member, without any temporary scaffolding below, so that navigation is not
interrupted, the cost of scaffolding is saved, and the difficulty of
building in deep water is obviated. The centre girder may be built on the
cantilevers and rolled into place or lifted from the water-level. Fig. 21
shows a typical cantilever bridge of American design. In this case the
shore ends of the cantilevers are anchored to the abutments. J.A.L. Waddell
has shown that, in some cases, it is convenient to erect simple independent
spans, by building them out as cantilevers and converting them into
independent girders after erection. Fig. 22 shows girders erected in this
way, the dotted lines being temporary members during erection, which are
removed afterwards. The side spans are erected first on staging and
anchored to the piers. From these, by the aid of the temporary members, the
centre span is built out from both sides. The most important cantilever
bridges so far erected or projected are as follows:--

[Illustration: FIG. 23.--Forth Bridge.]

(1) The Forth bridge (fig. 23). The original design was for a stiffened
suspension bridge, but after the fall of the Tay bridge in 1879 this was
abandoned. The bridge, which was begun in 1882 and completed in 1889, is at
the only narrowing of the Forth in a distance of 50 m., at a point where
the channel, about a mile in width, is divided by the island of Inchgarvie.
The length of the cantilever bridge is 5330 ft., made up thus: central
tower on Inchgarvie 260 ft.; Fife and Queensferry piers each 145 ft.; two
central girders between cantilevers each 350 ft.; and six cantilevers each
680 ft. The two main spans are each 1710 ft. The clear headway is 157 ft.,
and the extreme height of the towers above high water 361 ft. The outer
ends of the shore cantilevers are loaded to balance half the weight of the
central girder, the rolling load, and 200 tons in addition. An internal
viaduct of lattice girders carries a double line of rails. Provision is
made for longitudinal expansion due to change of temperature, for
distortion due to the sun acting on one side of the structure, and for the
wind acting on one side of the bridge. The amount of steel used was 38,000
tons exclusive of approach viaducts. (See _The Forth Bridge_, by W.
Westhofen; _Reports of the British Association_ (1884 and 1885); _Die Forth
Brücke_, von G. Barkhausen (Berlin, 1889); _The Forth Bridge_, by Philip
Phillips (1890); Vernon Harcourt, _Proc. Inst. C.E._ cxxi. p. 309.)

(2) The Niagara bridge of a total length of 910 ft., for two lines of
railway. Clear span between towers 495 ft. Completed in 1883, and more
recently strengthened (_Proc. Inst. C.E._ cvii. p. 18, and cxliv. p. 331).

[Illustration: FIG. 24.--Lansdowne Bridge.]

(3) The Lansdowne bridge (completed 1889) at Sukkur, over the Indus. The
clear span is 790 ft., and the suspended girder 200 ft. in length. The span
to the centres of the end uprights is 820 ft.; width between centres of
main uprights at bed-plate 100 ft., and between centres of main members at
end of cantilevers 20 ft. The bridge is for a single line of railway of 5
ft. 6 in. gauge. The back guys are the most heavily strained part of the
structure, the stress provided for being 1200 tons. This is due to the half
weight of centre girder, the weight of the cantilever itself, the rolling
load on half the bridge, and the wind pressure. The anchors are built up of
steel plates and angle, bars, and are buried in a large mass of concrete.
The area of each anchor plate, normal to the line of stress, is 32 ft. by
12 ft. The bridge was designed by Sir A. Rendel, the consulting engineer to
the Indian government (_Proc. Inst. C.E._ ciii. p. 123).

(4) The Red Rock cantilever bridge over the Colorado river, with a centre
span of 660 ft.

(5) The Poughkeepsie bridge over the Hudson, built 1886-1887. There are
five river and two shore spans. The girders over the second and fourth
spans are extended as cantilevers over the adjoining spans. The shore piers
carry cantilevers projecting one way over the river openings and the other
way over a shore span where it is secured to an anchorage. The girder spans
are 525 ft., the cantilever spans 547 ft., and the shore spans 201 ft.

[Illustration: FIG. 25.--Quebec Bridge (original design)]

(6) The Quebec bridge (fig. 25) over the St Lawrence, which collapsed while
in course of construction in 1907. This bridge, connecting very important
railway systems, was designed to carry two lines of rails, a highway and
electric railway on each side, all between the main trusses. Length between
abutments 3240 ft.; [v.04 p.0542] channel span 1800 ft.; suspended span 675
ft.; shore spans 562½ ft. Total weight of metal about 32,000 tons.

[Illustration: FIG. 26.--Jubilee Bridge over the Hugli.]

(7) The Jubilee bridge over the Hugli, designed by Sir Bradford Leslie, is
a cantilever bridge of another type (fig. 26). The girders are of the
Whipple Murphy type, but with curved top booms. The bridge carries a double
line of railway, between the main girders. The central double cantilever is
360 ft. long. The two side span girders are 420 ft long. The cantilever
rests on two river piers 120 ft. apart, centre to centre. The side girders
rest on the cantilevers on 15 in. pins, in pendulum links suspended from
similar pins in saddles 9 ft. high.

[Illustration: FIG. 27.--Coalbrookdale Bridge.]

11. (f) _Metal Arch Bridges._--The first iron bridge erected was
constructed by John Wilkinson (1728-1808) and Abraham Darby (1750-1791) in
1773-1779 at Coalbrookdale over the Severn (fig. 27). It had five cast iron
arched ribs with a centre span of 100 ft. This curious bridge is still in
use. Sir B. Baker stated that it had required patching for ninety years,
because the arch and the high side arches would not work together.
Expansion and contraction broke the high arch and the connexions between
the arches. When it broke they fished it. Then the bolts sheared or the
ironwork broke in a new place. He advised that there was nothing unsafe; it
was perfectly strong and the stress in vital parts moderate. All that
needed to be done was to fish the fractured ribs of the high arches, put
oval holes in the fishes, and not screw up the bolts too tight.

Cast iron arches of considerable span were constructed late in the 18th and
early in the 19th century. The difficulty of casting heavy arch ribs led to
the construction of cast iron arches of cast voussoirs, somewhat like the
voussoirs of masonry bridges. Such a bridge was the Wearmouth bridge,
designed by Rowland Burdon and erected in 1793-1796, with a span of 235 ft.
Southwark bridge over the Thames, designed by John Rennie with cast iron
ribs and erected in 1814-1819, has a centre span of 240 ft. and a rise of
24 ft. In Paris the Austerlitz (1800-1806) and Carrousel (1834-1836)
bridges had cast iron arches. In 1858 an aqueduct bridge was erected at
Washington by M.C. Meigs (1816-1892). This had two arched ribs formed by
the cast iron pipes through which the water passed. The pipes were 4 ft. in
diameter inside, 1½ in. thick, and were lined with staves of pine 3 in.
thick to prevent freezing. The span was 200 ft.

[Illustration: FIG. 28.--Arch of Bridge at Coblenz]

Fig. 28 shows one of the wrought iron arches of a bridge over the Rhine at
Coblenz. The bridge consists of three spans of about 315 ft. each.

[Illustration: FIG. 29.--St Louis Bridge.]

Of large-span bridges with steel arches, one of the most important is the
St Louis bridge over the Mississippi, completed in 1874 (fig. 29). The
river at St Louis is confined to a single channel, 1600 ft. wide, and in a
freshet in 1870 the scour reached a depth of 51 ft. Captain J.B. Eads, the
engineer, determined to establish the piers and abutments on rock at a
depth for the east pier and east abutment of 136 ft. below high water. This
was effected by caissons with air chambers and air locks, a feat
unprecedented in the annals of engineering. The bridge has three spans,
each formed of arches of cast steel. The centre span is 520 ft. and the
side spans 502 ft. in the clear. The rise of the centre arch is 47½ ft.,
and that of the side arches 46 ft. Each span has four steel double ribs of
steel tubes butted and clasped by wrought iron couplings. The vertical
bracing between the upper and lower members of each rib, which are 12 ft.
apart, centre to centre, consolidates them into a single arch. The arches
carry a double railway track and above this a roadway 54 ft. wide.

The St Louis bridge is not hinged, but later bridges have been constructed
with hinges at the springings and sometimes with hinges at the crown also.

The Alexander III. bridge over the Seine has fifteen steel ribs hinged at
crown and springings with a span of 353 ft. between centres of hinges and
358 ft. between abutments. The rise from side to centre hinges is 20 ft. 7
in. The roadway is 65½ ft. wide and footways 33 ft. (_Proc. Inst. C.E._
cxxx. p. 335).

[Illustration: FIG. 30.--Viaur Viaduct.]

The largest three-hinged-arch bridge constructed is the Viaur viaduct in
the south of France (fig. 30). The central span is 721 ft. 9 in. and the
height of the rails above the valley 380 ft. It has a very fine appearance,
especially when seen in perspective and not merely in elevation.

[Illustration: FIG. 31.--Douro Viaduct.]

Fig. 31 shows the Douro viaduct of a total length of 1158 ft. carrying a
railway 200 ft. above the water. The span of the central opening is 525 ft.
The principal rib is crescent-shaped 32.8 ft. deep [v.04 p.0543] at the
crown. Rolling load taken at 1.2 ton per ft. Weight of centre span 727
tons. The Luiz I. bridge is another arched bridge over the Douro, also
designed by T. Seyrig. This has a span of 566 ft. There are an upper and
lower roadway, 164 ft. apart vertically. The arch rests on rollers and is
narrowest at the crown. The reason given for this change of form was that
it more conveniently allowed the lower road to pass between the springings
and ensured the transmission of the wind stresses to the abutments without
interrupting the cross-bracing. Wire cables were used in the erection, by
which the members were lifted from barges and assembled, the operations
being conducted from the side piers.

[Illustration: FIG. 32.--Niagara Falls and Clifton Bridge.]

The Niagara Falls and Clifton steel arch (fig. 32) replaces the older
Roebling suspension bridge. The centre span is a two-hinged parabolic
braced rib arch, and there are side spans of 190 and 210 ft. The bridge
carries two electric-car tracks, two roadways and two footways. The main
span weighed 1629 tons, the side spans 154 and 166 tons (Buck, _Proc. Inst.
C.E._ cxliv. p. 70). Prof. Claxton Fidler, speaking of the arrangement
adopted for putting initial stress on the top chord, stated that this
bridge marked the furthest advance yet made in this type of construction.
When such a rib is erected on centering without initial stress, the
subsequent compression of the arch under its weight inflicts a bending
stress and excess of compression in the upper member at the crown. But the
bold expedients adopted by the engineer annulled the bending action.

The Garabit viaduct carries the railway near St Flour, in the Cantal
department, France, at 420 ft. above low water. The deepest part of the
valley is crossed by an arch of 541 ft. span, and 213 ft. rise. The bridge
is similar to that at Oporto, also designed by Seyrig. It is formed by a
crescent-shaped arch, continued on one side by four, on the other side by
two lattice girder spans, on iron piers. The arch is formed by two lattice
ribs hinged at the abutments. Its depth at the crown is 33 ft., and its
centre line follows nearly the parabolic line of pressures. The two arch
ribs are 65½ ft. apart at the springings and 20½ ft. at the crown. The
roadway girders are lattice, 17 ft. deep, supported from the arch ribs at
four points. The total length of the viaduct is 1715 ft. The lattice
girders of the side spans were first rolled into place, so as to project
some distance beyond the piers, and then the arch ribs were built out,
being partly supported by wire-rope cables from the lattice girders above.
The total weight of ironwork was 3200 tons and the cost £124,000 (_Annales
des travaux publiques_, 1884).

The Victoria Falls bridge over the Zambezi, designed by Sir Douglas Fox,
and completed in 1905, is a combination of girder and arch having a total
length of 650 ft. The centre arch is 500 ft. span, the rise of the crown 90
ft., and depth at crown 15 ft. The width between centres of ribs of main
arch is 27½ ft. at crown and 53 ft. 9 in at springings. The curve of the
main arch is a parabola. The bridge has a roadway of 30 ft. for two lines
of rails. Each half arch was supported by cables till joined at the centre.
An electric cableway of 900 ft. span capable of carrying 10 tons was used
in erection.

12. (g) _Movable Bridges_ can be closed to carry a road or railway or in
some cases an aqueduct, but can be opened to give free passage to
navigation. They are of several types:--

[Illustration: FIG. 33.]

(1) _Lifting Bridges._--The bridge with its platform is suspended from
girders above by chains and counterweights at the four corners (fig. 33 a).
It is lifted vertically to the required height when opened. Bridges of this
type are not very numerous or important.

(2) _Rolling Bridges._--The girders are longer than the span and the part
overhanging the abutment is counter-weighted so that the centre of gravity
is over the abutment when the bridge is rolled forward (fig. 33 b). To fill
the gap in the approaches when the bridge is rolled forward a frame
carrying that part of the road is moved into place sideways. At Sunderland,
the bridge is first lifted by a hydraulic press so as to clear the roadway
behind, and is then rolled back.

(3) _Draw or Bascule Bridges._--The fortress draw-bridge is the original
type, in which a single leaf, or bascule, turns round a horizontal hinge at
one abutment. The bridge when closed is supported on abutments at each end.
It is raised by chains and counterweights. A more common type is a bridge
with two leaves or bascules, one hinged at each abutment. When closed [v.04
p.0544] the bascules are locked at the centre (see fig. 13). In these
bridges each bascule is prolonged backwards beyond the hinge so as to
balance at the hinge, the prolongation sinking into the piers when the
bridge is opened.

(4) _Swing or Turning Bridges._--The largest movable bridges revolve about
a vertical axis. The bridge is carried on a circular base plate with a
central pivot and a circular track for a live ring and conical rollers. A
circular revolving platform rests on the pivot and rollers. A toothed arc
fixed to the revolving platform or to the live ring serves to give motion
to the bridge. The main girders rest on the revolving platform, and the
ends of the bridge are circular arcs fitting the fixed roadway. Three
arrangements are found: (a) the axis of rotation is on a pier at the centre
of the river and the bridge is equal armed (fig. 33 c), so that two
navigation passages are opened simultaneously. (b) The axis of rotation is
on one abutment, and the bridge is then usually unequal armed (fig. 33 d),
the shorter arm being over the land. (c) In some small bridges the shorter
arm is vertical and the bridge turns on a kind of vertical crane post at
the abutment (fig. 33 e).

(5) _Floating Bridges_, the roadway being carried on pontoons moored in the
stream.

The movable bridge in its closed position must be proportioned like a fixed
bridge, but it has also other conditions to fulfil. If it revolves about a
vertical axis its centre of gravity must always lie in that axis; if it
rolls the centre of gravity must always lie over the abutment. It must have
strength to support safely its own overhanging weight when moving.

At Konigsberg there is a road bridge of two fixed spans of 39 ft., and a
central span of 60 ft. between bearings, or 41 ft. clear, with balanced
bascules over the centre span. Each bascule consists of two main girders
with cross girders and stringers. The main girders are hung at each side on
a horizontal shaft 8-5/8 in. in diameter, and are 6 ft. deep at the hinge,
diminishing to 1 ft. 7 in. at the centre of the span. The counterweight is
a depressed cantilever arm 12 ft. long, overlapped by the fixed platform
which sinks into a recess in the masonry when the bridge opens. In closed
position the main girders rest on a bed plate on the face of the pier 4 ft.
3 in. beyond the shaft bearings. The bridge is worked by hydraulic power,
an accumulator with a load of 34 tons supplying pressure water at 630 lb
per sq. in. The bridge opens in 15 seconds and closes in 25 seconds.

At the opening span of the Tower bridge (fig. 13) there are four main
girders in each bascule. They project 100 ft. beyond and 62 ft. 6 in.
within the face of the piers. Transverse girders and bracings are inserted
between the main girders at 12 ft. intervals. The floor is of buckled
plates paved with wood blocks. The arc of rotation is 82°, and the axis of
rotation is 13 ft. 3 in. inside the face of the piers, and 5 ft. 7 in.
below the roadway. The weight of ballast in the short arms of the bascules
is 365 tons. The weight of each leaf including ballast is about 1070 tons.
The axis is of forged steel 21 in. in diameter and 48 ft. long. The axis
has eight bearings, consisting of rings of live rollers 4-7/16 in. in
diameter and 22 in. long. The bascules are rotated by pinions driven by
hydraulic engines working in steel sectors 42 ft. radius (_Proc. Inst.
C.E._ cxxvii. p. 35).

As an example of a swing bridge, that between Duluth and Superior at the
head of Lake Superior over the St Louis river may be described. The centre
opening is 500 ft., spanned by a turning bridge, 58 ft. wide. The girders
weighing 2000 tons carry a double track for trains between the girders and
on each side on cantilevers a trolley track, roadway and footway. The
bridge can be opened in 2 minutes, and is operated by two large electric
motors. These have a speed reduction from armature shaft to bridge column
of 1500 to 1, through four intermediate spur gears and a worm gear. The end
lifts which transfer the weight of the bridge to the piers when the span is
closed consist of massive eccentrics having a throw of 4 in. The clearance
is 2 in., so that the ends are lifted 2 in. This gives a load of 50 tons
per eccentric. One motor is placed at each end of the span to operate the
eccentrics and also to release the latches and raise the rails of the steam
track.

At Riga there is a floating pontoon bridge over the Duna. It consists of
fourteen rafts, 105 ft. in length, each supported by two pontoons placed 64
ft. apart. The pairs of rafts are joined by three baulks 15 ft. long laid
in parallel grooves in the framing. Two spans are arranged for opening
easily. The total length is 1720 ft. and the width 46 ft. The pontoons are
of iron, 85½ ft. in length, and their section is elliptical, 10½ ft.
horizontal and 12 ft. vertical. The displacement of each pontoon is 180
tons and its weight 22 tons. The mooring chains, weighing 22 lb per ft.,
are taken from the upstream end of each pontoon to a downstream screw pile
mooring and from the downstream end to an upstream screw pile.

13. _Transporter Bridges._--This new type of bridge consists of a high
level bridge from which is suspended a car at a low level. The car receives
the traffic and conveys it across the river, being caused to travel by
electric machinery on the high level bridge. Bridges of this type have been
erected at Portugalete, Bizerta, Rouen, Rochefort and more recently across
the Mersey between the towns of Widnes and Runcorn.

[Illustration: FIG. 34.--Widnes and Runcorn Transporter Bridge.]

The Runcorn bridge crosses the Manchester Ship Canal and the Mersey in one
span of 1000 ft., and four approach spans of 55½ ft. on one side and one
span on the other. The low-level approach roadways are 35 ft. wide with
footpaths 6 ft. wide on each side. The supporting structure is a cable
suspension bridge with stiffening girders. A car is suspended from the
bridge, carried by a trolley running on the underside of the stiffening
girders, the car being [v.04 p.0545] propelled electrically from one side
to the other. The underside of the stiffening girder is 82 ft. above the
river. The car is 55 ft. long by 24½ ft. wide. The electric motors are
under the control of the driver in a cabin on the car. The trolley is an
articulated frame 77 ft. long in five sections coupled together with pins.
To this are fixed the bearings of the running wheels, fourteen on each
side. There are two steel-clad series-wound motors of 36 B.H.P. For a test
load of 120 tons the tractive force is 70 lb per ton, which is sufficient
for acceleration, and maintaining speed against wind pressure. The brakes
are magnetic, with auxiliary handbrakes. Electricity is obtained by two gas
engines (one spare) each of 75 B.H.P.

On the opening day passengers were taken across at the rate of more than
2000 per hour in addition to a number of vehicles. The time of crossing is
3 or 4 minutes. The total cost of the structure was £133,000.

14. In the United States few railway companies design or build their own
bridges. General specifications as to span, loading, &c., are furnished to
bridge-building companies, which make the design under the direction of
engineers who are experts in this kind of work. The design, with strain
sheets and detail drawings, is submitted to the railway engineer with
estimates. The result is that American bridges are generally of
well-settled types and their members of uniform design, carefully
considered with reference to convenient and accurate manufacture. Standard
patterns of details are largely adopted, and more system is introduced in
the workshop than is possible where the designs are more varied. Riveted
plate girders are used up to 50 ft. span, riveted braced girders for spans
of 50 ft. to 75 ft., and pin-connected girders for longer spans. Since the
erection of the Forth bridge, cantilever bridges have been extensively
used, and some remarkable steel arch and suspension bridges have also been
constructed. Overhead railways are virtually continuous bridge
constructions, and much attention has been given to a study of the special
conditions appertaining to that case.

_Substructure._

15. The substructure of a bridge comprises the piers, abutments and
foundations. These portions usually consist of masonry in some form,
including under that general head stone masonry, brickwork and concrete.
Occasionally metal work or woodwork is used for intermediate piers.

When girders form the superstructure, the resultant pressure on the piers
or abutments is vertical, and the dimensions of these are simply regulated
by the sufficiency to bear this vertical load.

When arches form the superstructure, the abutment must be so designed as to
transmit the resultant thrust to the foundation in a safe direction, and so
distributed that no part may be unduly compressed. The intermediate piers
should also have considerable stability, so as to counterbalance the thrust
arising when one arch is loaded while the other is free from load.

For suspension bridges the abutment forming the anchorage must be so
designed as to be thoroughly stable under the greatest pull which the
chains can exert. The piers require to be carried above the platform, and
their design must be modified according to the type of suspension bridge
adopted. When the resultant pressure is not vertical on the piers these
must be constructed to meet the inclined pressure. In any stiffened
suspension bridge the action of the pier will be analogous to that of a
pier between two arches.

_Concrete in a shell_ is a name which might be applied to all the methods
of founding a pier which depend on the very valuable property which strong
hydraulic concrete possesses of setting into a solid mass under water. The
required space is enclosed by a wooden or iron shell; the soil inside the
shell is removed by dredging, or some form of mechanical excavator, until
the formation is reached which is to support the pier; the concrete is then
shot into the enclosed space from a height of about 10 ft., and rammed down
in layers about 1 ft. thick; it soon consolidates into a permanent
artificial stone.

_Piles_ are used as foundations in compressible or loose soil. The heads of
the piles are sawn off, and a platform of timber or concrete rests on them.
Cast iron and concrete reinforced piles are now used. _Screw piles_ are
cast iron piles which are screwed into the soil instead of being driven in.
At their end is fixed a blade of cast iron from two to eight times the
diameter of the shaft of the pile; the pitch of the screw varies from
one-half to one-fourth of the external diameter of the blade.

_Disk piles_ have been used in sand. These piles have a flat flange at the
bottom, and water is pumped in at the top of the pile, which is weighted to
prevent it from rising. Sand is thus blown or pumped from below the piles,
which are thus easily lowered in ground which baffles all attempts to drive
in piles by blows. In ground which is of the nature of quicksand, piles
will often slowly rise to their original position after each blow.

_Wells._--In some soils foundations may be obtained by the device of
building a masonry casing like that of a well and excavating the soil
inside; the casing gradually sinks and the masonry is continued at the
surface. This method is applicable in running sands. The interior of the
well is generally filled up with concrete or brick when the required depth
has been reached.

_Piers and Abutments._--Piers and abutments are of masonry, brickwork, or
cast or wrought iron. In the last case they consist of any number of hollow
cylindrical pillars, vertical or raking, turned and planed at the ends and
united by a projection or socket and by flanges and bolts. The pillars are
strengthened against lateral yielding by horizontal and diagonal bracing.
In some cases the piers are cast iron cylinders 10 ft. or more in diameter
filled with concrete.

[Illustration: FIG. 35.--Cylinder, Charing Cross Bridge.]

_Cylinder Foundations._--Formerly when bridge piers had to be placed where
a firm bearing stratum could only be reached at a considerable depth, a
timber cofferdam was used in which piles were driven down to the firm
stratum. On the piles the masonry piers were built. Many bridges so
constructed have stood for centuries. A great change of method arose when
iron cylinders and in some cases brick cylinders or wells were adopted for
foundations. These can be sunk to almost any depth or brought up to any
height, and are filled with Portland cement concrete. They are sometimes
excavated by grabs. Sometimes they are closed in and kept free of water by
compressed air so that excavation work can be carried on inside them (fig.
35). Sometimes in silty river beds they are sunk 100 ft. or more, for [v.04
p.0546] security against deep scouring of the river-bed in floods. In the
case of the Empress bridge over the Sutlej each pier consisted of three
brick wells, 19 ft. in diameter, sunk 110 ft. The piers of the Benares
bridge were single iron caissons, 65 ft. by 28 ft., sunk about 100 ft.,
lined with brick and filled with concrete. At the Forth bridge iron
caissons 70 ft. in diameter were sunk about 40 ft. into the bed of the
Forth. In this case the compressed air process was used.

16. _Erection._--Consideration of the local conditions affecting the
erection of bridges is always important, and sometimes becomes a
controlling factor in the determination of the design. The methods of
erection may be classed as--(1) erection on staging or falsework; (2)
floating to the site and raising; (3) rolling out from one abutment; (4)
building out member by member, the completed part forming the stage from
which additions are handled.

(1) In erection on staging, the materials available determine the character
of the staging; stacks of timber, earth banks, or built-up staging of piles
and trestles have all been employed, also iron staging, which can be
rapidly erected and moved from site to site. The most ordinary type of
staging consists of timber piles at nearly equal distances of 20 ft. to 30
ft., carrying a timber platform, on which the bridge is erected. Sometimes
a wide space is left for navigation, and the platform at this part is
carried by a timber and iron truss. When the headway is great or the river
deep, timber-braced piers or clusters of piles at distances of 50 ft. to
100 ft. may be used. These carry temporary trusses of timber or steel. The
Kuilenburg bridge in Holland, which has a span of 492 ft., was erected on a
timber staging of this kind, containing 81,000 cub. ft. of timber and 5
tons of bolts. The bridge superstructure weighed 2150 tons, so that 38 cub.
ft. of timber were used per ton of superstructure.

(2) The Britannia and Conway bridges were built on staging on shore, lifted
by pontoons, floated out to their position between the piers, and lastly
lifted into place by hydraulic presses. The Moerdyk bridge in Holland, with
14 spans of 328 ft., was erected in a similar way. The convenience of
erecting girders on shore is very great, but there is some risk in the
floating operations and a good deal of hauling plant is required.

(3) If a bridge consists of girders continuous over two or more spans, it
may be put together on the embankment at one end and rolled over the piers.
In some cases hauling tackle is used, in others power is applied by levers
and ratchets to the rollers on which the girders travel. In such rolling
operations the girder is subjected to straining actions different from
those which it is intended to resist, and parts intended for tension may be
in compression; hence it may need to be stiffened by timber during rolling.
The bending action on the bottom boom in passing over the rollers is also
severe. Modifications of the system have been adopted for bridges with
discontinuous spans. In narrow ravines a bridge of one span may be rolled
out, if the projecting end is supported on a temporary suspension cable
anchored on each side. The free end is slung to a block running on the
cable. If the bridge is erected when the river is nearly dry a travelling
stage may be constructed to carry the projecting end of the girder while it
is hauled across, the other end resting on one abutment. Sometimes a girder
is rolled out about one-third of its length, and then supported on a
floating pontoon.

(4) Some types of bridge can be built out from the abutments, the completed
part forming an erecting stage on which lifting appliances are fixed.
Generally, in addition, wire cables are stretched across the span, from
which lifting tackle is suspended. In bridges so erected the straining
action during erection must be studied, and material must be added to
resist erecting stresses. In the case of the St Louis bridge, half arches
were built out on either side of each pier, so that the load balanced.
Skeleton towers on the piers supported chains attached to the arched ribs
at suitable points. In spite of careful provision, much difficulty was
experienced in making the connexion at the crown, from the expansion due to
temperature changes. The Douro bridge was similarly erected. The girders of
the side spans were rolled out so as to overhang the great span by 105 ft.,
and formed a platform from which parts of the arch could be suspended.
Dwarf towers, built on the arch ring at the fifth panel from either side,
helped to support the girder above, in erecting the centre part of the arch
(Seyrig, _Proc. Inst. C.E._ lxiii. p. 177). The great cantilever bridges
have been erected in the same way, and they are specially adapted for
erection by building out.

_Straining Actions and Working Stresses._

17. In metal bridges wrought iron has been replaced by mild steel--a
stronger, tougher and better material. Ingot metal or mild steel was
sometimes treacherous when first introduced, and accidents occurred, the
causes of which were obscure. In fact, small differences of composition or
variations in thermal treatment during manufacture involve relatively large
differences of quality. Now it is understood that care must be taken in
specifying the exact quality and in testing the material supplied.
Structural wrought iron has a tenacity of 20 to 22½ tons per sq. in. in the
direction of rolling, and an ultimate elongation of 8 or 10% in 8 in.
Across the direction of rolling the tenacity is about 18 tons per sq. in.,
and the elongation 3% in 8 in. Steel has only a small difference of quality
in different directions. There is still controversy as to what degree of
hardness, or (which is nearly the same thing) what percentage of carbon,
can be permitted with safety in steel for structures.

The qualities of steel used may be classified as follows:--(a) Soft steel,
having a tenacity of 22½ to 26 tons per sq. in., and an elongation of 32 to
24% in 8 in. (b) Medium steel, having a tenacity of 26 to 34 tons per sq.
in., and 28 to 25% elongation. (c) Moderately hard steel, having a tenacity
of 34 to 37 tons per sq. in., and 17% elongation, (d) Hard steel, having a
tenacity of 37 to 40 tons per sq. in., and 10% elongation. Soft steel is
used for rivets always, and sometimes for the whole superstructure of a
bridge, but medium steel more generally for the plates, angle bars, &c.,
the weight of the bridge being then reduced by about 7% for a given factor
of safety. Moderately hard steel has been used for the larger members of
long-span bridges. Hard steel, if used at all, is used only for compression
members, in which there is less risk of flaws extending than in tension
members. With medium or moderately hard steel all rivet holes should be
drilled, or punched 1/8 in. less in diameter than the rivet and reamed out,
so as to remove the ring of material strained by the punch.

In the specification for bridge material, drawn up by the British
Engineering Standards Committee, it is provided that the steel shall be
acid or basic open-hearth steel, containing not more than 0.06% of sulphur
or phosphorus. Plates, angles and bars, other than rivet bars, must have a
tensile strength of 28 to 32 tons per sq. in., with an elevation of 20% in
8 in. Rivet bars tested on a gauge length eight times the diameter must
have a tensile strength of 26 to 30 tons per sq. in. and an elongation of
25%.

18. _Straining Actions._--The external forces acting on a bridge may be
classified as follows:--

(1) The _live_ or _temporary load_, for road bridges the weight of a dense
crowd uniformly distributed, or the weight of a heavy wagon or traction
engine; for railway bridges the weight of the heaviest train likely to come
on the bridge. (2) An allowance is sometimes made for _impact_, that is the
dynamical action of the live load due to want of vertical balance in the
moving parts of locomotives, to irregularities of the permanent way, or to
yielding of the structure. (3) The _dead load_ comprises the weight of the
main girders, flooring and wind bracing, or the total weight of the
superstructure exclusive of any part directly carried by the piers. This is
usually treated as uniformly distributed over the span. (4) The _horizontal
pressure_ due to a wind blowing transversely to the span, which becomes of
importance in long and high bridges. (5) The _longitudinal drag_ due to the
friction of a train when braked, about one-seventh of the weight of the
train. (6) On a curved bridge the _centrifugal load_ due to the radical
acceleration of the train. If w is the weight of a locomotive in tons, r
the radius of curvature of the track, v the velocity in feet per sec.; then
the horizontal force exerted on the bridge is wv^2/gr tons. (7) In some
cases, especially in arch and suspension bridges, changes of temperature
set up stresses equivalent to those produced by an external load. In Europe
a variation of temperature of 70° C. or 126° F. is commonly assumed. For
this the expansion is about 1 in. in 100 ft. Generally a structure should
be anchored at one point and free to move if possible in other directions.
Roughly, if expansion is prevented, a stress of one ton per sq. in. is set
up in steel structures for each 12° change of temperature.

i. _Live Load on Road Bridges._--A dense crowd of people may be taken as a
uniform load of 80 to 120 lb per sq. ft. But in recent times the weight of
traction engines and wagons which pass over bridges has increased, and this
kind of load generally produces greater straining action than a crowd of
people. In manufacturing districts and near large towns loads of 30 tons
may come on road bridges, and county and borough authorities insist on
provision being made for such loads. In Switzerland roads are divided into
three classes according to their importance, and the following loads are
prescribed, the designer having to provide sufficient strength either for a
uniformly distributed crowd, or for a heavy wagon anywhere on the
roadway:-- [v.04 p.0547]

| Crowd, | Wagon,
| lb per sq. ft. | tons per axle.
| |
Main Roads ....... | 92 | 10 with 13 ft. wheel base
Secondary Roads .. | 72 | 6 " 10 " "
Other Roads ...... | 51 | 3 " 8 " "

In England still larger loads are now provided for. J.C. Inglis (_Proc.
Inst. C.E._ cxli. p. 35) has considered two cases--(a) a traction engine
and boiler trolley, and (b) a traction engine and trucks loaded with
granite. He has calculated the equivalent load per foot of span which would
produce the same maximum bending moments. The following are some of the
results:--

Span Ft. |10. |20. |30. |40. |50. |
| | | | | |
Equivalent load in tons per ft. run, | | | | | |
Case a ............................. |1.75|0.95|0.70|0.73|0.72|
Do. Case b ......................... |3.25|1.7 |1.3 |1.2 |1.15|

Large as these loads are on short spans, they are not more than must often
be provided for.

_Live Load on Railway Bridges._--The live load is the weight of the
heaviest train which can come on the bridge. In the earlier girder bridges
the live load was taken to be equivalent to a uniform load of 1 ton per
foot run for each line of way. At that time locomotives on railways of 4
ft. 8½ in. gauge weighed at most 35 to 45 tons, and their length between
buffers was such that the average load did not exceed 1 ton per foot run.
Trains of wagons did not weigh more than three-quarters of a ton per foot
run when most heavily loaded. The weights of engines and wagons are now
greater, and in addition it is recognized that the concentration of the
loading at the axles gives rise to greater straining action, especially in
short bridges, than the same load uniformly distributed along the span.
Hence many of the earlier bridges have had to be strengthened to carry
modern traffic. The following examples of some of the heaviest locomotives
on English railways is given by W.B. Farr (_Proc. Inst. C.E._ cxli. p.
12):--

_Passenger Engines._

Total weights, tons ......... 84.35 | 98.90 | 91.90 | 85.48
Tons per ft. over all ....... 1.58 | 1.71 | 1.62 | 1.61
Tons per ft. of wheel base .. 1.92 | 2.04 | 1.97 | 1.95
Maximum axle load, tons ..... 19.00 | 16.00 | 18.70 | 18.50

_Goods Engines._

Total weight, tons .......... 77.90 | 78.80 | 76.46 | 75.65
Tons per ft. over all ....... 1.54 | 1.50 | 1.54 | 1.51
Tons per ft. of wheel base .. 2.02 | 2.02 | 2.03 | 2.00
Maximum axle load, tons ..... 15.90 | 16.00 | 13.65 | 15.50

_Tank Engines._

Total weight, tons .......... 53.80 | 58.61 | 60.80 | 47.00
Tons per ft. over all ....... 1.60 | 1.68 | 1.70 | 1.55
Tons per ft. of wheel base .. 2.45 | 2.52 | 2.23 | 3.03
Maximum axle load, tons ..... 17.54 | 15.29 | 17.10 | 15.77

Farr has drawn diagrams of bending moment for forty different very heavy
locomotives on different spans, and has determined for each case a uniform
load which at every point would produce as great a bending moment as the
actual wheel loads. The following short abstract gives the equivalent
uniform load which produces bending moments as great as those of any of the
engines calculated:--

Span in Ft. | Load per ft. run equivalent
| to actual Wheel Loads in Tons,
| for each Track.
|
5.0 | 7.6
10.0 | 4.85
20.0 | 3.20
30.0 | 2.63
50.0 | 2.24
100.0 | 1.97

Fig. 36 gives the loads per axle and the distribution of loads in some
exceptionally heavy modern British locomotives.

[Illustration: Express Passenger Engine, G.N. Ry.]

[Illustration: Goods Engine, L. & Y. Ry.]

[Illustration: Passenger Engine, Cal. Ry.
FIG. 36.]

[v.04 p.0548] In Austria the official regulations require that railway
bridges shall be designed for at least the following live loads per foot
run and per track:--

| Span. | Live Load in Tons. |
| - - - - - - - -|- - - - - - - - - - - - - - - -|
|Metres. | Ft. | Per metre run. | Per ft. run. |
| | | | |
| 1 | 3.3 | 20 | 6.1 |
| 2 | 6.6 | 15 | 4.6 |
| 5 | 16.4 | 10 | 3.1 |
| 20 | 65.6 | 5 | 1.5 |
| 30 | 98.4 | 4 | 1.2 |

It would be simpler and more convenient in designing short bridges if,
instead of assuming an equivalent uniform rolling load, agreement could be
come to as to a typical heavy locomotive which would produce stresses as
great as any existing locomotive on each class of railway. Bridges would
then be designed for these selected loads, and the process would be safer
in dealing with flooring girders and shearing forces than the assumption of
a uniform load.

Some American locomotives are very heavy. Thus a consolidation engine may
weigh 126 tons with a length over buffers of 57 ft., corresponding to an
average load of 2.55 tons per ft. run. Also long ore wagons are used which
weigh loaded two tons per ft. run. J.A.L. Waddell (_De Pontibus_, New York,
1898) proposes to arrange railways in seven classes, according to the live
loads which may be expected from the character of their traffic, and to
construct bridges in accordance with this classification. For the lightest
class, he takes a locomotive and tender of 93.5 tons, 52 ft. between
buffers (average load 1.8 tons per ft. run), and for the heaviest a
locomotive and tender weighing 144.5 tons, 52 ft. between buffers (average
load 2.77 tons per ft. run). Wagons he assumes to weigh for the lightest
class 1.3 tons per ft. run and for the heaviest 1.9 tons. He takes as the
live load for a bridge two such engines, followed by a train of wagons
covering the span. Waddell's tons are short tons of 2000 lb.

ii. _Impact._--If a vertical load is imposed suddenly, but without
velocity, work is done during deflection, and the deformation and stress
are momentarily double those due to the same load at rest on the structure.
No load of exactly this kind is ever applied to a bridge. But if a load is
so applied that the deflection increases with speed, the stress is greater
than that due to a very gradually applied load, and vibrations about a mean
position are set up. The rails not being absolutely straight and smooth,
centrifugal and lurching actions occur which alter the distribution of the
loading. Again, rapidly changing forces, due to the moving parts of the
engine which are unbalanced vertically, act on the bridge; and, lastly,
inequalities of level at the rail ends give rise to shocks. For all these
reasons the stresses due to the live load are greater than those due to the
same load resting quietly on the bridge. This increment is larger on the
flooring girders than on the main ones, and on short main girders than on
long ones. The impact stresses depend so much on local conditions that it
is difficult to fix what allowance should be made. E.H. Stone (_Trans. Am.
Soc. of C.E._ xli. p. 467) collated some measurements of deflection taken
during official trials of Indian bridges, and found the increment of
deflection due to impact to depend on the ratio of dead to live load. By
plotting and averaging he obtained the following results:--

_Excess of Deflection and straining Action of a moving Load over that due
to a resting Load._

Dead load in per cent | | | | | | | |
of total load .... | 10 | 20 | 30 | 40 | 50 | 70 | 90 |
Live load in per cent | | | | | | | |
of total load .... | 90 | 80 | 70 | 60 | 50 | 30 | 10 |
Ratio of live to dead | | | | | | | |
load ............. | 9 | 4 |2.3 |1.5 |1.0 |0.43|0.10|
Excess of deflection | | | | | | | |
and stress due to | | | | | | | |
moving load | | | | | | | |
per cent ......... | 23 | 13 | 8 |5.5 |4.0 |1.6 |0.3 |

These results are for the centre deflections of main girders, but Stone
infers that the augmentation of stress for any member, due to causes
included in impact allowance, will be the same percentage for the same
ratios of live to dead load stresses. Valuable measurements of the
deformations of girders and tension members due to moving trains have been
made by S.W. Robinson (_Trans. Am. Soc. C.E._ xvi.) and by F.E. Turneaure
(_Trans. Am. Soc. C.E._ xli.). The latter used a recording deflectometer
and two recording extensometers. The observations are difficult, and the
inertia of the instrument is liable to cause error, but much care was
taken. The most striking conclusions from the results are that the
locomotive balance weights have a large effect in causing vibration, and
next, that in certain cases the vibrations are cumulative, reaching a value
greater than that due to any single impact action. Generally: (1) At speeds
less than 25 m. an hour there is not much vibration. (2) The increase of
deflection due to impact at 40 or 50 m. an hour is likely to reach 40 to
50% for girder spans of less than 50 ft. (3) This percentage decreases
rapidly for longer spans, becoming about 25% for 75-ft. spans. (4) The
increase per cent of boom stresses due to impact is about the same as that
of deflection; that in web bracing bars is rather greater. (5) Speed of
train produces no effect on the mean deflection, but only on the magnitude
of the vibrations.

A purely empirical allowance for impact stresses has been proposed,
amounting to 20% of the live load stresses for floor stringers; 15% for
floor cross girders; and for main girders, 10% for 40-ft. spans, and 5% for
100-ft. spans. These percentages are added to the live load stresses.

iii. _Dead Load._--The dead load consists of the weight of main girders,
flooring and wind-bracing. It is generally reckoned to be uniformly
distributed, but in large spans the distribution of weight in the main
girders should be calculated and taken into account. The weight of the
bridge flooring depends on the type adopted. Road bridges vary so much in
the character of the flooring that no general rule can be given. In railway
bridges the weight of sleepers, rails, &c., is 0.2 to 0.25 tons per ft. run
for each line of way, while the rail girders, cross girders, &c., weigh
0.15 to 0.2 tons. If a footway is added about 0.4 ton per ft. run may be
allowed for this. The weight of main girders increases with the span, and
there is for any type of bridge a limiting span beyond which the dead load
stresses exceed the assigned limit of working stress.

Let W_l be the total live load, W_f the total flooring load on a bridge of
span l, both being considered for the present purpose to be uniform per ft.
run. Let k(W_l+W_f) be the weight of main girders designed to carry
W_l+W_f, but not their own weight in addition. Then

W_g = (W_l+W_f)(k+k^2+k^3 ...)

will be the weight of main girders to carry W_l+W_f and their own weight
(Buck, _Proc. Inst. C.E._ lxvii. p. 331). Hence,

W_g = (W_l+W_f)k/(1-k).

Since in designing a bridge W_l+W_f is known, k(W_l+W_f) can be found from
a provisional design in which the weight W_g is neglected. The actual
bridge must have the section of all members greater than those in the
provisional design in the ratio k/(1-k).

Waddell (_De Pontibus_) gives the following convenient empirical relations.
Let w_1, w_2 be the weights of main girders per ft. run for a live load p
per ft. run and spans l_1, l_2. Then

w_2/w_1 = ½ [l_2/l_1+(l_2/l_1)^2].

Now let w_1', w_2' be the girder weights per ft. run for spans l_1, l_2,
and live loads p' per ft. run. Then

w_2'/w_2 = 1/5(1+4p'/p)

w_2'/w_1 = 1/10[l_2/l_1+(l_2/l_1)^2](1+4p'/p)

A partially rational approximate formula for the weight of main girders is
the following (Unwin, _Wrought Iron Bridges and Roofs_, 1869, p. 40):--

Let w = total live load per ft. run of girder; w_2 the weight of platform
per ft. run; w_3 the weight of main girders per ft. run, all in tons; l =
span in ft.; s = average stress in tons per sq. in. on gross section of
metal; d = depth of girder at centre in ft.; r = ratio of span to depth of
girder so that r = l/d. Then

w_3 = (w_1+w_2)l^2/(Cds-l_2) = (w_1+w_2)lr/(Cs-lr),

where C is a constant for any type of girder. It is not easy to fix the
average stress s per sq. in. of gross section. Hence the formula is more
useful in the form

w = (w_1+w_2)l^2/(Kd-l^2) = (w_1+w_2)lr/(K-lr)

where K = (w_1+w_2+w_3)lr/w_3 is to be deduced from the data of some bridge
previously designed with the same working stresses. From some known
examples, C varies from 1500 to 1800 for iron braced parallel or bowstring
girders, and from 1200 to 1500 for similar girders of steel. K = 6000 to
7200 for iron and = 7200 to 9000 for steel bridges.

iv. _Wind Pressure._--Much attention has been given to wind action since
the disaster to the Tay bridge in 1879. As to the maximum wind pressure on
small plates normal to the wind, there is not much doubt. Anemometer
observations show that pressures of 30 lb per sq. ft. occur in storms
annually in many localities, and that occasionally higher pressures are
recorded in exposed positions. Thus at Bidstone, Liverpool, where the gauge
has an exceptional exposure, a pressure of 80 lb per sq. ft. has been
observed. In tornadoes, such as that at St Louis in 1896, it has been
calculated, from the stability of structures overturned, that pressures of
45 to 90 lb per sq. ft. must have been reached. As to anemometer pressures,
it should be observed that the recorded pressure is made up of a positive
front and negative (vacuum) back pressure, but in structures the latter
must be absent or only partially developed. Great difference of opinion
exists as to whether on large surfaces the average pressure per sq. ft. is
as great as on small surfaces, such as anemometer plates. The experiments
of Sir B. Baker at the Forth bridge showed that on a surface 30 ft. × 15
ft. the intensity of pressure was less than on a similarly exposed
anemometer plate. In the case of bridges there is the further difficulty
that some surfaces partially [v.04 p.0549] shield other surfaces; one
girder, for instance, shields the girder behind it (see _Brit. Assoc.
Report_, 1884). In 1881 a committee of the Board of Trade decided that the
maximum wind pressure on a vertical surface in Great Britain should be
assumed in designing structures to be 56 lb per sq. ft. For a plate girder
bridge of less height than the train, the wind is to be taken to act on a
surface equal to the projected area of one girder and the exposed part of a
train covering the bridge. In the case of braced girder bridges, the wind
pressure is taken as acting on a continuous surface extending from the
rails to the top of the carriages, plus the vertical projected area of so
much of one girder as is exposed above the train or below the rails. In
addition, an allowance is made for pressure on the leeward girder according
to a scale. The committee recommended that a factor of safety of 4 should
be taken for wind stresses. For safety against overturning they considered
a factor of 2 sufficient. In the case of bridges not subject to Board of
Trade inspection, the allowance for wind pressure varies in different
cases. C. Shaler Smith allows 300 lb per ft. run for the pressure on the
side of a train, and in addition 30 lb per sq. ft. on twice the vertical
projected area of one girder, treating the pressure on the train as a
travelling load. In the case of bridges of less than 50 ft. span he also
provides strength to resist a pressure of 50 lb per sq. ft. on twice the
vertical projection of one truss, no train being supposed to be on the
bridge.

19. _Stresses Permitted._--For a long time engineers held the convenient
opinion that, if the total dead and live load stress on any section of a
structure (of iron) did not exceed 5 tons per sq. in., ample safety was
secured. It is no longer possible to design by so simple a rule. In an
interesting address to the British Association in 1885, Sir B. Baker
described the condition of opinion as to the safe limits of stress as
chaotic. "The old foundations," he said, "are shaken, and engineers have
not come to an agreement respecting the rebuilding of the structure. The
variance in the strength of existing bridges is such as to be apparent to
the educated eye without any calculation. In the present day engineers are
in accord as to the principles of estimating the magnitude of the stresses
on the members of a structure, but not so in proportioning the members to
resist those stresses. The practical result is that a bridge which would be
passed by the English Board of Trade would require to be strengthened 5% in
some parts and 60% in others, before it would be accepted by the German
government, or by any of the leading railway companies in America." Sir B.
Baker then described the results of experiments on repetition of stress,
and added that "hundreds of existing bridges which carry twenty trains a
day with perfect safety would break down quickly under twenty trains an
hour. This fact was forced on my attention nearly twenty-five years ago by
the fracture of a number of girders of ordinary strength under a
five-minutes' train service."

Practical experience taught engineers that though 5 tons per sq. in. for
iron, or 6½ tons per sq. in. for steel, was safe or more than safe for long
bridges with large ratio of dead to live load, it was not safe for short
ones in which the stresses are mainly due to live load, the weight of the
bridge being small. The experiments of A. Wöhler, repeated by Johann
Bauschinger, Sir B. Baker and others, show that the breaking stress of a
bar is not a fixed quantity, but depends on the range of variation of
stress to which it is subjected, if that variation is repeated a very large
number of times. Let K be the breaking strength of a bar per unit of
section, when it is loaded once gradually to breaking. This may be termed
the statical breaking strength. Let k_{max.} be the breaking strength of
the same bar when subjected to stresses varying from k_{max.} to k_{min.}
alternately and repeated an indefinitely great number of times; k_{min.} is
to be reckoned + if of the same kind as k_{max.} and - if of the opposite
kind (tension or thrust). The range of stress is therefore
k_{max.}-k_{min.}, if the stresses are both of the same kind, and
k_{max.}+k_{min.}, if they are of opposite kinds. Let [Delta] = k_{max.} ±
k_{min.} = the range of stress, where [Delta] is always positive. Then
Wöhler's results agree closely with the rule,

k_{max.} = ½[Delta]+[root](K²-n[Delta]K),

where n is a constant which varies from 1.3 to 2 in various qualities of
iron and steel. For ductile iron or mild steel it may be taken as 1.5. For
a statical load, range of stress nil, [Delta] = 0, k_{max.} = K, the
statical breaking stress. For a bar so placed that it is alternately loaded
and the load removed, [Delta] = k_{max.} and k_{max.} = 0.6 K. For a bar
subjected to alternate tension and compression of equal amount, [Delta] = 2
f_{max.} and k_{max.} = 0.33 K. The safe working stress in these different
cases is k_{max.} divided by the factor of safety. It is sometimes said
that a bar is "fatigued" by repeated straining. The real nature of the
action is not well understood, but the word fatigue may be used, if it is
not considered to imply more than that the breaking stress under repetition
of loading diminishes as the range of variation increases.

It was pointed out as early as 1869 (Unwin, _Wrought Iron Bridges and
Roofs_) that a rational method of fixing the working stress, so far as
knowledge went at that time, would be to make it depend on the ratio of
live to dead load, and in such a way that the factor of safety for the live
load stresses was double that for the dead load stresses. Let A be the dead
load and B the live load, producing stress in a bar; [rho] = B/A the ratio
of live to dead load; f_1 the safe working limit of stress for a bar
subjected to a dead load only and f the safe working stress in any other
case. Then

f_1 (A+B)/(A+2B) = f_1(1+[rho])/(1+2[rho]).

The following table gives values of f so computed on the assumption that
f_1 = 7½ tons per sq. in. for iron and 9 tons per sq. in. for steel.

_Working Stress for combined Dead and Live Load. Factor of Safety twice as
great for Live Load as for Dead Load._

----------------------+-------+----------+-----------------------------+
| Ratio | 1+[rho] |Values of f, tons per sq. in.|
| [rho] | ------- +-----------------------------+
| | 1+2[rho] | Iron. | Mild Steel.|
----------------------+-------+----------+----------------+------------+
All dead load | 0 | 1.00 | 7.5 | 9.0 |
| .25 | 0.83 | 6.2 | 7.5 |
| .33 | 0.78 | 5.8 | 7.0 |
| .50 | 0.75 | 5.6 | 6.8 |
| .66 | 0.71 | 5.3 | 6.4 |
Live load = Dead load | 1.00 | 0.66 | 4.9 | 5.9 |
| 2.00 | 0.60 | 4.5 | 5.4 |
| 4.00 | 0.56 | 4.2 | 5.0 |
All live load | [inf] | 0.50 | 3.7 | 4.5 |
----------------------+-------+----------+----------------+------------+

Bridge sections designed by this rule differ little from those designed by
formulae based directly on Wöhler's experiments. This rule has been revived
in America, and appears to be increasingly relied on in bridge-designing.
(See _Trans. Am. Soc. C.E._ xli. p. 156.)

The method of J.J. Weyrauch and W. Launhardt, based on an empirical
expression for Wöhler's law, has been much used in bridge designing (see
_Proc. Inst. C.E._ lxiii. p. 275). Let t be the _statical breaking
strength_ of a bar, loaded once gradually up to fracture (t = breaking load
divided by original area of section); u the breaking strength of a bar
loaded and unloaded an indefinitely great number of times, the stress
varying from u to 0 alternately (this is termed the _primitive strength_);
and, lastly, let s be the breaking strength of a bar subjected to an
indefinitely great number of repetitions of stresses equal and opposite in
sign (tension and thrust), so that the stress ranges alternately from s to
-s. This is termed the _vibration strength_. Wöhler's and Bauschinger's
experiments give values of t, u, and s, for some materials. If a bar is
subjected to alternations of stress having the range [Delta] =
f_{max.}-f_{min.}, then, by Wöhler's law, the bar will ultimately break, if

f_{max.} = F[Delta], . . . (1)

where F is some unknown function. Launhardt found that, for stresses always
of the same kind, F = (t-u)/(t-f_{max.}) approximately agreed with
experiment. For stresses of different kinds Weyrauch found F =
(u-s)/(2u-s-f_{max.}) to be similarly approximate. Now let
f_{max.}/f_{min.} = [phi], where [phi] is + or - according as the stresses
are of the same or opposite signs. Putting the values of F in (1) and
solving for f_{max.}, we get for the breaking stress of a bar subjected to
repetition of varying stress,

f_{max.} = u(1+(t-u)[phi]/u) [Stresses of same sign.]
f_{max.} = u(1+(u-s)[phi]/u) [Stresses of opposite sign.]

The working stress in any case is f_{max.} divided by a factor of safety.
Let that factor be 3. Then Wöhler's results for iron and Bauschinger's for
steel give the following equations for tension or thrust:--

Iron, working stress, f = 4.4 (1+½[phi])
Steel, working stress, f = 5.87 (1+½[phi]).

In these equations [phi] is to have its + or - value according to the case
considered. For shearing stresses the working stress may have 0.8 of its
value for tension. The following table gives values of the working stress
calculated by these equations:--

_Working Stress for Tension or Thrust by Launhardt and Weyrauch Formula._

------------------------+-------+-----------+--------------------+
| [phi] | [phi] | Working Stress f, |
| | 1 + ----- | tons per sq. in. |
| | 2 +--------------------+
| | | Iron. | Steel. |
------------------------+-------+-----------+--------------------+
All dead load | 1.0 | 1.5 | 6.60 | 8.80 |
| 0.75 | 1.375 | 6.05 | 8.07 |
| 0.50 | 1.25 | 5.50 | 7.34 |
| 0.25 | 1.125 | 4.95 | 6.60 |
All live load | 0.00 | 1.00 | 4.40 | 5.87 |
| -0.25 | 0.875 | 3.85 | 5.14 |
| -0.50 | 0.75 | 3.30 | 4.40 |
| -0.75 | 0.625 | 2.75 | 3.67 |
Equal stresses + and - | -1.00 | 0.500 | 2.20 | 2.93 |
------------------------+-------+-----------+--------------------+

[v.04 p.0550] To compare this with the previous table, [phi] = (A+B)/A =
1+[rho]. Except when the limiting stresses are of opposite sign, the two
tables agree very well. In bridge work this occurs only in some of the
bracing bars.

It is a matter of discussion whether, if fatigue is allowed for by the
Weyrauch method, an additional allowance should be made for impact. There
was no impact in Wöhler's experiments, and therefore it would seem rational
to add the impact allowance to that for fatigue; but in that case the
bridge sections become larger than experience shows to be necessary. Some
engineers escape this difficulty by asserting that Wöhler's results are not
applicable to bridge work. They reject the allowance for fatigue (that is,
the effect of repetition) and design bridge members for the total dead and
live load, plus a large allowance for impact varied according to some
purely empirical rule. (See Waddell, _De Pontibus_, p.7.) Now in applying
Wöhler's law, f_{max.} for any bridge member is found for the maximum
possible live load, a live load which though it may sometimes come on the
bridge and must therefore be provided for, is not the usual live load to
which the bridge is subjected. Hence the range of stress,
f_{max.}-f_{min.}, from which the working stress is deduced, is not the
ordinary range of stress which is repeated a practically infinite number of
times, but is a range of stress to which the bridge is subjected only at
comparatively long intervals. Hence practically it appears probable that
the allowance for fatigue made in either of the tables above is sufficient
to cover the ordinary effects of impact also.

English bridge-builders are somewhat hampered in adopting rational limits
of working stress by the rules of the Board of Trade. Nor do they all
accept the guidance of Wöhler's law. The following are some examples of
limits adopted. For the Dufferin bridge (steel) the working stress was
taken at 6.5 tons per sq. in. in bottom booms and diagonals, 6.0 tons in
top booms, 5.0 tons in verticals and long compression members. For the
Stanley bridge at Brisbane the limits were 6.5 tons per sq. in. in
compression boom, 7.0 tons in tension boom, 5.0 tons in vertical struts,
6.5 tons in diagonal ties, 8.0 tons in wind bracing, and 6.5 tons in cross
and rail girders. In the new Tay bridge the limit of stress is generally 5
tons per sq. in., but in members in which the stress changes sign 4 tons
per sq. in. In the Forth bridge for members in which the stress varied from
0 to a maximum frequently, the limit was 5.0 tons per sq. in., or if the
stress varied rarely 5.6 tons per sq. in.; for members subjected to
alternations of tension and thrust frequently 3.3 tons per sq. in. or 5
tons per sq. in. if the alternations were infrequent. The shearing area of
rivets in tension members was made 1½ times the useful section of plate in
tension. For compression members the shearing area of rivets in butt-joints
was made half the useful section of plate in compression.

[Illustration: FIG. 37.]

20. _Determination of Stresses in the Members of Bridges._--It is
convenient to consider beam girder or truss bridges, and it is the stresses
in the main girders which primarily require to be determined. A main girder
consists of an upper and lower flange, boom or chord and a vertical web.
The loading forces to be considered are vertical, the horizontal forces due
to wind pressure are treated separately and provided for by a horizontal
system of bracing. For practical purposes it is accurate enough to consider
the booms or chords as carrying exclusively the horizontal tension and
compression and the web as resisting the whole of the vertical and, in a
plate web, the equal horizontal shearing forces. Let fig. 37 represent a
beam with any system of loads W_1, W_2, ... W_n.

The reaction at the right abutment is

R_2 = W_1x_1/l+W_2x_2/l+...

That at the left abutment is

R_1 = W_1+W_2+...-R_2.

Consider any section a b. The total shear at a b is

S = R-[Sigma](W_1+W_2 ...)

where the summation extends to all the loads to the left of the section.
Let p_1, p_2 ... be the distances of the loads from a b, and p the distance
of R_1 from a b; then the bending moment at a b is

M = R_1p-[Sigma](W_1p_1+W_2p_2 ...)

where the summation extends to all the loads to the left of a b. If the
loads on the right of the section are considered the expressions are
similar and give the same results.

If A_t A_c are the cross sections of the tension and compression flanges or
chords, and h the distance between their mass centres, then on the
assumption that they resist all the direct horizontal forces the total
stress on each flange is

H_t = H_c = M/h

and the intensity of stress of tension or compression is

f_t = M/A_th,
f_c = M/A_ch.

If A is the area of the plate web in a vertical section, the intensity of
shearing stress is

f_x = S/A

and the intensity on horizontal sections is the same. If the web is a
braced web, then the vertical component of the stress in the web bars cut
by the section must be equal to S.

[Illustration: FIG. 38.]

21. _Method of Sections. A. Ritter's Method._--In the case of braced
structures the following method is convenient: When a section of a girder
can be taken cutting only three bars, the stresses in the bars can be found
by taking moments. In fig. 38 m n cuts three bars, and the forces in the
three bars cut by the section are C, S and T. There are to the left of the
section the external forces, R, W_1, W_2. Let s be the perpendicular from
O, the join of C and T on the direction of S; t the perpendicular from A,
the join of C and S on the direction of T; and c the perpendicular from B,
the join of S and T on the direction of C. Taking moments about O,

R_x-W_1(x+a)-W_2(x+2a) = Ss;

taking moments about A,

R3a-W_12a-W_2a = Tt;

and taking moments about B,

R2a-W_1a = Cc

Or generally, if M_1 M_2 M_3 are the moments of the external forces to the
left of O, A, and B respectively, and s, t and c the perpendiculars from O,
A and B on the directions of the forces cut by the section, then

Ss = M_1; Tt = M_2 and Cc = M_3.

Still more generally if H is the stress on any bar, h the perpendicular
distance from the join of the other two bars cut by the section, and M is
the moment of the forces on one side of that join,

Hh = M.

[Illustration: Fig. 39.]

[Illustration: Fig. 40.]

22. _Distribution of Bending Moment and Shearing Force._--Let a girder of
span l, fig. 39, supported at the ends, carry a fixed load W at m from the
right abutment. The reactions at the abutments are R_1 = Wm/l and R_2 =
W(l-m)/l. The shears on vertical sections to the left and right of the load
are R_1 and -R_2, and the distribution of shearing force is given by two
rectangles. Bending moment increases uniformly from either abutment to the
load, at which the bending moment is M = R_2m = R_1(l-m). The distribution
of bending moment is given by the ordinates of a triangle. Next let the
girder carry a uniform load w per ft. run (fig. 40). The total load [v.04
p.0551] is wl; the reactions at abutments, R_1 = R_2 = ½wl. The
distribution of shear on vertical sections is given by the ordinates of a
sloping line. The greatest bending moment is at the centre and = M_c =
1/8wl^2. At any point x from the abutment, the bending moment is M =
½wx(l-x), an equation to a parabola.

[Illustration: Fig. 41.]

[Illustration: Fig. 42.]

23. _Shear due to Travelling Loads._--Let a uniform train weighing w per
ft. run advance over a girder of span 2c, from the left abutment. When it
covers the girder to a distance x from the centre (fig. 41) the total load
is w(c+x); the reaction at B is

R_2 = w(c+x)×(c+x)/4c = w/4c(c+x)²,

[Illustration: FIG. 41.]

[Illustration: FIG. 42.]

which is also the shearing force at C for that position of the load. As the
load travels, the shear at the head of the train will be given by the
ordinates of a parabola having its vertex at A, and a maximum F_{max.} =
-½wl at B. If the load travels the reverse way, the shearing force at the
head of the train is given by the ordinates of the dotted parabola. The
greatest shear at C for any position of the load occurs when the head of
the train is at C. For any load p between C and B will increase the
reaction at B and therefore the shear at C by part of p, but at the same
time will diminish the shear at C by the whole of p. The web of a girder
must resist the maximum shear, and, with a travelling load like a railway
train, this is greater for partial than for complete loading. Generally a
girder supports both a dead and a live load. The distribution of total
shear, due to a dead load w_l per ft. run and a travelling load w_l per ft.
run, is shown in fig. 42, arranged so that the dead load shear is added to
the maximum travelling load shear of the same sign.

[Illustration: FIG. 43.]

24. _Counterbracing._--In the case of girders with braced webs, the tension
bars of which are not adapted to resist a thrust, another circumstance due
to the position of the live load must be considered. For a train advancing
from the left, the travelling load shear in the left half of the span is of
a different sign from that due to the dead load. Fig. 43 shows the maximum
shear at vertical sections due to a dead and travelling load, the latter
advancing (fig. 43, a) from the left and (fig. 43, b) from the right
abutment. Comparing the figures it will be seen that over a distance x near
the middle of the girder the shear changes sign, according as the load
advances from the left or the right. The bracing bars, therefore, for this
part of the girder must be adapted to resist either tension or thrust.
Further, the range of stress to which they are subjected is the sum of the
stresses due to the load advancing from the left or the right.

[Illustration: FIG. 44.]

[Illustration: FIG. 45.]

[Illustration: FIG. 46.]

25. _Greatest Shear when concentrated Loads travel over the Bridge._--To
find the greatest shear with a set of concentrated loads at fixed
distances, let the loads advance from the left abutment, and let C be the
section at which the shear is required (fig. 44). The greatest shear at C
may occur with W_1 at C. If W_1 passes beyond C, the shear at C will
probably be greatest when W_2 is at C. Let R be the resultant of the loads
on the bridge when W_1 is at C. Then the reaction at B and shear at C is
Rn/l. Next let the loads advance a distance a so that W_2 comes to C. Then
the shear at C is R(n+a)/l-W_1, plus any reaction d at B, due to any
additional load which has come on the girder during the movement. The shear
will therefore be increased by bringing W_2 to C, if Ra/l+d > W_1 and d is
generally small and negligible. This result is modified if the action of
the load near the section is distributed to the bracing intersections by
rail and cross girders. In fig. 45 the action of W is distributed to A and
B by the flooring. Then the loads at A and B are W(p-x)/p and Wx/p. Now let
C (fig. 46) be the section at which the greatest shear is required, and let
the loads advance from the left till W_1 is at C. If R is the resultant of
the loads then on the girder, the reaction at B and shear at C is Rn/l. But
the shear may be greater when W_2 is at C. In that case the shear at C
becomes R(n+a)/l+d-W_1, if a > p, and R(n+a)/l+d-W_1a/p, if a < p. If we
neglect d, then the shear increases by moving W_2 to C, if Ra/l > W_1 in
the first case, and if Ra/l > W_1a/p in the second case.

[Illustration: FIG. 47.]

[Illustration: FIG. 48.]

26. _Greatest Bending Moment due to travelling concentrated Loads._--For
the greatest bending moment due to a travelling live load, let a load of w
per ft. run advance from the left abutment (fig. 47), and let its centre be
at x from the left abutment. The reaction at B is 2wx²/l and the bending
moment at any section C, at m from the left abutment, is 2wx²/(l-m)/l,
which increases as x increases till the span is covered. Hence, for uniform
travelling loads, the bending moments are greatest when the loading is
complete. In that case the loads on either side of C are proportional to m
and l-m. In the case of a series of travelling loads at fixed distances
apart passing over the girder from the left, let W_1, W_2 (fig. 48), at
distances x and x+a from the left abutment, be their resultants on either
side of C. Then the reaction at B is W_1x/l+W_2(x+a)/l. The bending moment
at C is

M = W_1x(l-m)/l+W_2m{1-(x+a)/l}.

If the loads are moved a distance [Delta]x to the right, the bending moment
becomes

M+[Delta]M = W_1(x+[Delta]x)(l-m)/l+W_2m{1-(x+[Delta]x+a)/l}
[Delta]m = W_1[Delta]x(l-m)/l-W_2[Delta]xm/l,

and this is positive or the bending moment increases, if W_1(l-m) > W_2m,
or if W_1/m > W_2/(l-m). But these are the average loads per ft. run to the
left and right of C. Hence, if the average load to the left of a section is
greater than that to the right, the bending moment at the section will be
increased by moving the loads to the right, and vice versa. Hence the
maximum bending moment at C for a series of travelling loads will occur
when the average load is the same on either side of C. If one of the loads
is at C, spread over a very small distance in the neighbourhood of C, then
a very small displacement of the loads will permit the fulfilment of the
condition. Hence the criterion for the position of the loads which makes
the moment at C greatest is this: one load must be at C, and the other
loads must be distributed, so that the average loads per ft. on either side
of C (the load at C being neglected) are nearly equal. If the loads are
very unequal in magnitude or distance this condition may be satisfied for
more than one position of the loads, but it is not difficult to ascertain
which position gives the maximum moment. Generally one of the largest of
the loads must be at C with as many others to right and left as is
consistent with that condition.

[Illustration: FIG. 49.]

This criterion may be stated in another way. The greatest bending moment
will occur with one of the greatest loads at the section, and when this
further condition is satisfied. Let fig. 49 represent a beam with the
series of loads travelling from the right. Let a b be [v.04 p.0552] the
section considered, and let W_x be the load at a b when the bending moment
there is greatest, and W_n the last load to the right then on the bridge.
Then the position of the loads must be that which satisfies the condition

x W_1+W_2+... W_{x-1}
--- greater than ------------------------
l W_1+W_2+... W_n

x W_1+W_2+... W_x
--- less than ------------------------
l W_1+W_2+... W_n

[Illustration: FIG. 50.]

Fig. 50 shows the curve of bending moment under one of a series of
travelling loads at fixed distances. Let W_1, W_2, W_3 traverse the girder
from the left at fixed distances a, b. For the position shown the
distribution of bending moment due to W_1 is given by ordinates of the
triangle A'CB'; that due to W_2 by ordinates of A'DB'; and that due to W_3
by ordinates A'EB'. The total moment at W_1, due to three loads, is the sum
mC+mn+mo of the intercepts which the triangle sides cut off from the
vertical under W_1. As the loads move over the girder, the points C, D, E
describe the parabolas M_1, M_2, M_3, the middle ordinates of which are
¼W_1l, ¼W_2l, and ¼W_3l. If these are first drawn it is easy, for any
position of the loads, to draw the lines B'C, B'D, B'E, and to find the sum
of the intercepts which is the total bending moment under a load. The lower
portion of the figure is the curve of bending moments under the leading
load. Till W_1 has advanced a distance a only one load is on the girder,
and the curve A"F gives bending moments due to W_1 only; as W_1 advances to
a distance a+b, two loads are on the girder, and the curve FG gives moments
due to W_1 and W_2. GB" is the curve of moments for all three loads
W_1+W_2+W_3.

[Illustration: FIG. 51.]

Fig. 51 shows maximum bending moment curves for an extreme case of a short
bridge with very unequal loads. The three lightly dotted parabolas are the
curves of maximum moment for each of the loads taken separately. The three
heavily dotted curves are curves of maximum moment under each of the loads,
for the three loads passing over the bridge, at the given distances, from
left to right. As might be expected, the moments are greatest in this case
at the sections under the 15-ton load. The heavy continuous line gives the
last-mentioned curve for the reverse direction of passage of the loads.

With short bridges it is best to draw the curve of maximum bending moments
for some assumed typical set of loads in the way just described, and to
design the girder accordingly. For longer bridges the funicular polygon
affords a method of determining maximum bending moments which is perhaps
more convenient. But very great accuracy in drawing this curve is
unnecessary, because the rolling stock of railways varies so much that the
precise magnitude and distribution of the loads which will pass over a
bridge cannot be known. All that can be done is to assume a set of loads
likely to produce somewhat severer straining than any probable actual
rolling loads. Now, except for very short bridges and very unequal loads, a
parabola can be found which includes the curve of maximum moments. This
parabola is the curve of maximum moments for a travelling load uniform per
ft. run. Let w_e be the load per ft. run which would produce the maximum
moments represented by this parabola. Then w_e may be termed the uniform
load per ft. equivalent to any assumed set of concentrated loads. Waddell
has calculated tables of such equivalent uniform loads. But it is not
difficult to find w_e, approximately enough for practical purposes, very
simply. Experience shows that (a) a parabola having the same ordinate at
the centre of the span, or (b) a parabola having the same ordinate at
one-quarter span as the curve of maximum moments, agrees with it closely
enough for practical designing. A criterion already given shows the
position of any set of loads which will produce the greatest bending moment
at the centre of the bridge, or at one-quarter span. Let M_c and M_a be
those moments. At a section distant x from the centre of a girder of span
2c, the bending moment due to a uniform load w_e per ft run is

M = ½w_e(c-x)(c+x).

Putting x = 0, for the centre section

M_c = ½w_ec^2;

and putting x = ½c, for section at quarter span

M_a = 3/8w_ec^2.

From these equations a value of w_e can be obtained. Then the bridge is
designed, so far as the direct stresses are concerned, for bending moments
due to a uniform dead load and the uniform equivalent load w_e.

[Illustration: FIG. 52.]

27. _Influence Lines._--In dealing with the action of travelling loads much
assistance may be obtained by using a line termed an _influence line_. Such
a line has for abscissa the distance of a load from one end of a girder,
and for ordinate the bending moment or shear at any given section, or on
any member, due to that load. Generally the influence line is drawn for
unit load. In fig. 52 let A'B' be a girder supported at the ends and let it
be required to investigate the bending moment at C' due to unit load in any
position on the girder. When the load is at F', the reaction at B' is m/l
and the moment at C' is m(l-x)/l, which will be reckoned positive, when it
resists a tendency of the right-hand part of the girder to turn
counter-clockwise. Projecting A'F'C'B' on to the horizontal AB, take Ff =
m(l-x)/l, the moment at C of unit load at F. If this process is repeated
for all positions of the load, we get the influence line AGB for the
bending moment at C. The area AGB is termed the influence area. The
greatest moment CG at C is x(l-x)/l. To use this line to investigate the
maximum moment at C due to a series of travelling loads at fixed distances,
let P_1, P_2, P_3, ... be the loads which at the moment considered are at
distances m_1, m_2, ... from the left abutment. Set off these distances
along AB and let y_1, y_2, ... be the corresponding ordinates of the
influence curve (y = Ff) on the verticals under the loads. Then the moment
at C due to all the loads is

M = P_1y_1+P_2y_2+...

[v.04 p.0553] [Illustration: FIG. 53.]

The position of the loads which gives the greatest moment at C may be
settled by the criterion given above. For a uniform travelling load w per
ft. of span, consider a small interval Fk = [Delta]m on which the load is
w[Delta]m. The moment due to this, at C, is wm(l-x)[Delta]m/l. But
m(l-x)[Delta]m/l is the area of the strip Ffhk, that is y[Delta]m. Hence
the moment of the load on [Delta]m at C is wy[Delta]m, and the moment of a
uniform load over any portion of the girder is w × the area of the
influence curve under that portion. If the scales are so chosen that a inch
represents 1 in. ton of moment, and b inch represents 1 ft. of span, and w
is in tons per ft. run, then ab is the unit of area in measuring the
influence curve.

If the load is carried by a rail girder (stringer) with cross girders at
the intersections of bracing and boom, its effect is distributed to the
bracing intersections D'E' (fig. 53), and the part of the influence line
for that bay (panel) is altered. With unit load in the position shown, the
load at D' is (p-n)/p, and that at E' is n/p. The moment of the load at C
is m(l-x)/l-n(p-n)/p. This is the equation to the dotted line RS (fig. 52).

[Illustration: FIG. 54.]

[Illustration: FIG. 55]

If the unit load is at F', the reaction at B' and the shear at C' is m/l,
positive if the shearing stress resists a tendency of the part of the
girder on the right to move upwards; set up Ff = m/l (fig. 54) on the
vertical under the load. Repeating the process for other positions, we get
the influence line AGHB, for the shear at C due to unit load anywhere on
the girder. GC = x/l and CH = -(l-x)/l. The lines AG, HB are parallel. If
the load is in the bay D'E' and is carried by a rail girder which
distributes it to cross girders at D'E', the part of the influence line
under this bay is altered. Let n (Fig. 55) be the distance of the load from
D', x_1 the distance of D' from the left abutment, and p the length of a
bay. The loads at D', E, due to unit weight on the rail girder are (p-n)/p
and n/p. The reaction at B' is {(p-n)x_1+n(x_1+p)}/pl. The shear at C' is
the reaction at B' less the load at E', that is, {p(x_1+n)-nl}/pl, which is
the equation to the line DH (fig. 54). Clearly, the distribution of the
load by the rail girder considerably alters the distribution of shear due
to a load in the bay in which the section considered lies. The total shear
due to a series of loads P_1, P_2, ... at distances m_1, m_2, ... from the
left abutment, y_1, y_2, ... being the ordinates of the influence curve
under the loads, is S = P_1y_1+P_2y_2+.... Generally, the greatest shear S
at C will occur when the longer of the segments into which C divides the
girder is fully loaded and the other is unloaded, the leading load being at
C. If the loads are very unequal or unequally spaced, a trial or two will
determine which position gives the greatest value of S. The greatest shear
at C' of the opposite sign to that due to the loading of the longer segment
occurs with the shorter segment loaded. For a uniformly distributed load w
per ft. run the shear at C is w × the area of the influence curve under the
segment covered by the load, attention being paid to the sign of the area
of the curve. If the load rests directly on the main girder, the greatest +
and - shears at C will be w × AGC and -w × CHB. But if the load is
distributed to the bracing intersections by rail and cross girders, then
the shear at C' will be greatest when the load extends to N, and will have
the values w × ADN and -w × NEB. An interesting paper by F.C. Lea, dealing
with the determination of stress due to concentrated loads, by the method
of influence lines will be found in _Proc. Inst. C.E._ clxi. p.261.

Influence lines were described by Fränkel, _Der Civilingenieur_, 1876. See
also _Handbuch der Ingenieur-wissenschaften_, vol. ii. ch. x. (1882), and
Levy, _La Statique graphique_ (1886). There is a useful paper by Prof. G.F.
Swain (_Trans. Am. Soc. C.E._ xvii., 1887), and another by L.M. Hoskins
(_Proc. Am. Soc. C.E._ xxv., 1899).

[Illustration: FIG. 56.]

28. _Eddy's Method._--Another method of investigating the maximum shear at
a section due to any distribution of a travelling load has been given by
Prof. H.T. Eddy (_Trans. Am. Soc. C.E._ xxii., 1890). Let hk (fig. 56)
represent in magnitude and position a load W, at x from the left abutment,
on a girder AB of span l. Lay off kf, hg, horizontal and equal to l. Join f
and g to h and k. Draw verticals at A, B, and join no. Obviously no is
horizontal and equal to l. Also mn/mf = hk/kf or mn-W(l-x)/l, which is the
reaction at A due to the load at C, and is the shear at any point of AC.
Similarly, po is the reaction at B and shear at any point of CB. The shaded
rectangles represent the distribution of shear due to the load at C, while
no may be termed the datum line of shear. Let the load move to D, so that
its distance from the left abutment is x+a. Draw a vertical at D,
intersecting fh, kg, in s and q. Then qr/ro = hk/hg or ro = W(l-x-a)/l,
which is the reaction at A and shear at any point of AD, for the new
position of the load. Similarly, rs = W(x+a)/l is the shear on DB. The
distribution of shear is given by the partially shaded rectangles. For the
application of this method to a series of loads Prof. Eddy's paper must be
referred to.

29. _Economic Span._--In the case of a bridge of many spans, there is a
length of span which makes the cost of the bridge least. The cost of
abutments and bridge flooring is practically independent of the length of
span adopted. Let P be the cost of one pier; C the cost of the main girders
for one span, erected; n the number of spans; l the length of one span, and
L the length of the bridge between abutments. Then, n = L/l nearly. Cost of
piers (n-1)P. Cost of main girders nG. The cost of a pier will not vary
materially with the span adopted. It depends mainly on the character of the
foundations and height at which the bridge is carried. The cost of the main
girders for one span will vary nearly as the square of the span for any
given type of girder and intensity of live load. That is, G = al², where a
is a constant. Hence the total cost of that part of the bridge which varies
with the span adopted is--

C = (n-i)P+nal²
= LP/l-P+Lal.

Differentiating and equating to zero, the cost is least when

dC LP
-- = - -- + La = 0,
dl l²

/*
P = al² = G;

that is, when the cost of one pier is equal to the cost erected of the main
girders of one span. Sir Guilford Molesworth puts this in a convenient but
less exact form. Let G be the cost of superstructure of a 100-ft. span
erected, and P the cost of one pier with its protection. Then the economic
span is l = 100[root]P/[root]G.

30. _Limiting Span._--If the weight of the main girders of a bridge, per
ft. run in tons, is--

w_3 = (w_1+w_2)lr/(K-lr)

according to a formula already given, then w_3 becomes infinite if k-lr =
0, or if

l = K/r,

[v.04 p.0554] where l is the span in feet and r is the ratio of span to
depth of girder at centre. Taking K for steel girders as 7200 to 9000,

Limiting Span in Ft.
r = 12 l = 600 to 750
= 10 = 720 to 900
= 8 = 900 to 1120

[Illustration: FIG. 58.]

[Illustration: FIG. 59.]

[Illustration: FIG. 60.]

In a three-span bridge continuous girders are lighter than discontinuous
ones by about 45% for the dead load and 15% for the live load, if no
allowance is made for ambiguity due to uncertainty as to the level of the
supports. The cantilever and suspended girder types are as economical and
free from uncertainty as to the stresses. In long-span bridges the
cantilever system permits erection by building out, which is economical and
sometimes necessary. It is, however, unstable unless rigidly fixed at the
piers. In the Forth bridge stability is obtained partly by the great excess
of dead over live load, partly by the great width of the river piers. The
majority of bridges not of great span have girders with parallel booms.
This involves the fewest difficulties of workmanship and perhaps permits
the closest approximation of actual to theoretical dimensions of the parts.
In spans over 200 ft. it is economical to have one horizontal boom and one
polygonal (approximately parabolic) boom. The hog-backed girder is a
compromise between the two types, avoiding some difficulties of
construction near the ends of the girder.

[Illustration: FIG. 61.]

[Illustration: FIG. 62.]

Most braced girders may be considered as built up of two simple forms of
truss, the king-post truss (fig. 61, a), or the queen-post truss (fig. 61,
b). These may be used in either the upright or the inverted position. A
_multiple truss_ consists of a number of simple trusses, e.g. Bollman
truss. Some timber bridges consist of queen-post trusses in the upright
position, as shown diagrammatically in fig. 62, where the circles indicate
points at which the flooring girders transmit load to the main girders.
_Compound_ trusses consist of simple trusses used as primary, secondary and
tertiary trusses, the secondary supported on the primary, and the tertiary
on the secondary. Thus, the Fink truss consists of king-post trusses; the
Pratt truss (fig. 63) and the Whipple truss (fig. 64) of queen-post trusses
alternately upright and inverted.

[Illustration: FIG. 63.]

[Illustration: FIG. 64.]

A combination bridge is built partly of timber, partly of steel, the
compression members being generally of timber and the tension members of
steel. On the Pacific coast, where excellent timber is obtainable and steel
works are distant, combination bridges are still largely used (Ottewell,
_Trans. Am. Soc. C.E._ xxvii. p. 467). The combination bridge at Roseburgh,
Oregon, is a cantilever bridge, The shore arms are 147 ft. span, the river
arms 105 ft., and the suspended girder 80 ft., the total distance between
anchor piers being 584 ft. The floor beams, floor and railing are of
timber. The compression members are of timber, except the struts and bottom
chord panels next the river piers, which are of steel. The tension members
are of iron and the pins of steel. The chord blocks and post shoes are of
cast-iron.

[Illustration: FIG. 65.]

33. _Graphic Method of finding the Stresses in Braced Structures._--Fig. 65
shows a common form of bridge truss known as a _Warren girder_, with lines
indicating external forces applied to the joints; half the load carried
between the two lower joints next the piers on either side is directly
carried by the abutments. The sum of the two upward vertical reactions must
clearly be equal to the sum of the loads. The lines in the diagram
represent the directions of a series of forces which must all be in
equilibrium; these lines may, for an object to be explained in the next
paragraph, be conveniently named by the letters in the spaces which they
separate instead of by the method usually employed in geometry. Thus we
shall call the first inclined line on the left hand the line AG, the line
representing the first force on the top left-hand joint AB, the first
horizontal member at the top left hand the line BH, &c; similarly each
point requires at least three letters to denote it; the top first left-hand
joint may be called ABHG, being the point where these four spaces meet. In
this method of lettering, every enclosed space must be designated by a
letter; all external forces must be represented by lines _outside_ the
frame, and each space between any two forces must receive a distinctive
letter; this method of lettering was first proposed by O. Henrici and R. H.
Bow (_Economics of Construction_), and is convenient in applying the theory
of reciprocal figures to the computation of stresses on frames.

34. _Reciprocal Figures._--J. Clerk Maxwell gave (_Phil. Mag. 1864_) the
following definition of reciprocal figures:--"Two plane figures are
reciprocal when they consist of an equal number of lines so that
corresponding lines in the two figures are parallel, and corresponding
lines which converge to a point in one figure form a closed polygon in the
other."

Let a frame (without redundant members), and the external forces which keep
it in equilibrium, be represented by a diagram constituting one of these
two plane figures, then the lines in the other plane figure or the
reciprocal will represent in direction and magnitude the forces between the
joints of the frame, and, consequently, the stress on each member, as will
now be explained.

Reciprocal figures are easily drawn by following definite rules, and afford
therefore a simple method of computing the stresses on members of a frame.

The external forces on a frame or bridge in equilibrium under those forces
may, by a well-known proposition in statics, be represented by a closed
polygon, each side of which is parallel to one force, and represents the
force in magnitude as well as in direction. The sides of the polygon may be
arranged in any order, provided care is taken so to draw them that in
passing round the polygon in one direction this direction may for each side
correspond to the direction of the force which it represents.

[Illustration: FIG. 66.]

This polygon of forces may, by a slight extension of the above definition,
be called the _reciprocal figure_ of the external forces, if the sides are
arranged in the same order as that of the joints on which they act, so that
if the joints and forces be numbered 1, 2, 3, 4, &c., passing round the
outside of the frame in one direction, and returning at last to joint 1,
then in the polygon the side representing the force 2 will be next the side
representing the force 1, and will be followed by the side representing the
force 3, and so forth. [v.04 p.0555] This polygon falls under the
definition of a reciprocal figure given by Clerk Maxwell, if we consider
the frame as a point in equilibrium under the external forces.

Fig. 66 shows a frame supported at the two end joints, and loaded at each
top joint. The loads and the supporting forces are indicated by arrows.
Fig. 67a shows the reciprocal figure or polygon for the external forces on
the assumption that the reactions are slightly inclined. The lines in fig.
67 a, lettered in the usual manner, correspond to the forces indicated by
arrows in fig. 66, and lettered according to Bow's method. When all the
forces are vertical, as will be the case in girders, the polygon of
external forces will be reduced to two straight lines, fig. 67 b,
superimposed and divided so that the length AX represents the load AX, the
length AB the load AB, the length YX the reaction YX, and so forth. The
line XZ consists of a series of lengths, as XA, AB ... DZ, representing the
loads taken in their order. In subsequent diagrams the two reaction lines
will, for the sake of clearness, be drawn as if slightly inclined to the
vertical.

[Illustration: FIG. 67.]

If there are no redundant members in the frame there will be only two
members abutting at the point of support, for these two members will be
sufficient to balance the reaction, whatever its direction may be; we can
therefore draw two triangles, each having as one side the reaction YX, and
having the two other sides parallel to these two members; each of these
triangles will represent a polygon of forces in equilibrium at the point of
support. Of these two triangles, shown in fig. 67 c, select that in which
the letters X and Y are so placed that (naming the apex of the triangle E)
the lines XE and YE are the lines parallel to the two members of the same
name in the frame (fig. 66). Then the triangle YXE is the reciprocal figure
of the three lines YX, XE, EY in the frame, and represents the three forces
in equilibrium at the point YXE of the frame. The direction of YX, being a
thrust upwards, shows the direction in which we must go round the triangle
YXE to find the direction of the two other forces; doing this we find that
the force XE must act down towards the point YXE, and the force EY away
from the same point. Putting arrows on the frame diagram to indicate the
direction of the forces, we see that the member EY must pull and therefore
act as a tie, and that the member XE must push and act as a strut. Passing
to the point XEFA we find two known forces, the load XA acting downwards,
and a push from the strut XE, which, being in compression, must push at
both ends, as indicated by the arrow, fig. 66. The directions and
magnitudes of these two forces are already drawn (fig. 67 a) in a fitting
position to represent part of the polygon of forces at XEFA; beginning with
the upward thrust EX, continuing down XA, and drawing AF parallel to AF in
the frame we complete the polygon by drawing EF parallel to EF in the
frame. The point F is determined by the intersection of the two lines, one
beginning at A, and the other at E. We then have the polygon of forces
EXAF, the reciprocal figure of the lines meeting at that point in the
frame, and representing the forces at the point EXAF; the direction of the
forces on EH and XA being known determines the direction of the forces due
to the elastic reaction of the members AF and EF, showing AF to push as a
strut, while EF is a tie. We have been guided in the selection of the
particular quadrilateral adopted by the rule of arranging the order of the
sides so that the same letters indicate corresponding sides in the diagram
of the frame and its reciprocal. Continuing the construction of the diagram
in the same way, we arrive at fig. 67 d as the complete reciprocal figure
of the frame and forces upon it, and we see that each line in the
reciprocal figure measures the stress on the corresponding member in the
frame, and that the polygon of forces acting at any point, as IJKY, in the
frame is represented by a polygon of the same name in the reciprocal
figure. The direction of the force in each member is easily ascertained by
proceeding in the manner above described. A single known force in a polygon
determines the direction of all the others, as these must all correspond
with arrows pointing the same way round the polygon. Let the arrows be
placed on the frame round each joint, and so as to indicate the direction
of each force on that joint; then when two arrows point to one another on
the same piece, that piece is a tie; when they point from one another the
piece is a strut. It is hardly necessary to say that the forces exerted by
the two ends of any one member must be equal and opposite. This method is
universally applicable where there are no redundant members. The reciprocal
figure for any loaded frame is a complete formula for the stress on every
member of a frame of that particular class with loads on given joints.

[Illustration: FIG. 68]

[Illustration: FIG. 69]

Consider a Warren girder (fig. 68), loaded at the top and bottom joints.
Fig. 69 b is the polygon of external forces, and 69 c is half the
reciprocal figure. The complete reciprocal figure is shown in fig. 69 a.

The method of sections already described is often more convenient than the
method of reciprocal figures, and the method of influence lines is also
often the readiest way of dealing with braced girders.

35. _Chain Loaded uniformly along a Horizontal Line._--If the lengths of
the links be assumed indefinitely short, the chain under given simple
distributions of load will take the form of comparatively simple
mathematical curves known as catenaries. The true catenary is that assumed
by a chain of uniform weight per unit of length, but the form generally
adopted for suspension bridges is that assumed by a chain under a weight
uniformly distributed relatively to a horizontal line. This curve is a
parabola.

Remembering that in this case the centre bending moment [Sigma]wl will be
equal to wL²/8, we see that the horizontal tension H at the vertex for a
span L (the points of support being at equal heights) is given by the
expression

1 . . . H = wL²/8y,

or, calling x the distance from the vertex to the point of support,

H = wx²/2y,

The value of H is equal to the maximum tension on the bottom flange, or
compression on the top flange, of a girder of equal span, equally and
similarly loaded, and having a depth equal to the dip of the suspension
bridge.

[Illustration: FIG. 70.]

Consider any other point F of the curve, fig. 70, at a distance x [v.04
p.0556] from the vertex, the horizontal component of the resultant (tangent
to the curve) will be unaltered; the vertical component V will be simply
the sum of the loads between O and F, or wx. In the triangle FDC, let FD be
tangent to the curve, FC vertical, and DC horizontal; these three sides
will necessarily be proportional respectively to the resultant tension
along the chain at F, the vertical force V passing through the point D, and
the horizontal tension at O; hence

H : V = DC : FC = wx²/2y : wx = x/2 : y,

hence DC is the half of OC, proving the curve to be a parabola.

The value of R, the tension at any point at a distance x from the vertex,
is obtained from the equation

R² = H²+V² = w²x^4/4y²+w²x²,

or,

2 . . . R = wx[root](1+x²/4y²).

Let i be the angle between the tangent at any point having the co-ordinates
x and y measured from the vertex, then

3 . . . tan i = 2y/x.

Let the length of half the parabolic chain be called s, then

4 . . . s = x+2y²/3x.

The following is the approximate expression for the relation between a
change [Delta]s in the length of the half chain and the corresponding
change [Delta]y in the dip:--

s+[Delta]s = x+(2/3x) {y²+2y[Delta]y+([Delta]y)²} =
x+2y²/3x+4y[Delta]y/3x+2[Delta]y²/3x,

or, neglecting the last term,

5 . . . [Delta]s = 4y[Delta]y/3x,

and

6 . . . [Delta]y = 3x[Delta]s/4y.

From these equations the deflection produced by any given stress on the
chains or by a change of temperature can be calculated.

[Illustration: FIG. 71.]

36. _Deflection of Girders._-- Let fig. 71 represent a beam bent by
external loads. Let the origin O be taken at the lowest point of the bent
beam. Then the deviation y = DE of the neutral axis of the bent beam at any
point D from the axis OX is given by the relation

d²y M
--- = -- ,
dx² EI

where M is the bending moment and I the amount of inertia of the beam at D,
and E is the coefficient of elasticity. It is usually accurate enough in
deflection calculations to take for I the moment of inertia at the centre
of the beam and to consider it constant for the length of the beam. Then

dy 1
-- = ---[Integral]Mdx
dx EI

1
y = ---[Integral][Integral]Mdx².
EI

The integration can be performed when M is expressed in terms of x. Thus
for a beam supported at the ends and loaded with w per inch length M =
w(a²-x²), where a is the half span. Then the deflection at the centre is
the value of y for x = a, and is

5 wa^4
[delta] = --- ----.
24 EI

The radius of curvature of the beam at D is given by the relation

R = EI/M.

[Illustration: FIG. 72.]

37. _Graphic Method of finding Deflection._--Divide the span L into any
convenient number n of equal parts of length l, so that nl = L; compute the
radii of curvature R_1, R_2, R_3 for the several sections. Let measurements
along the beam be represented according to any convenient scale, so that
calling L_1 and l_1 the lengths to be drawn on paper, we have L = aL_1; now
let r_1, r_2, r_3 be a series of radii such that r_1 = R_1/ab, r_2 =
R_2/ab, &c., where b is any convenient constant chosen of such magnitude as
will allow arcs with the radii, r_1, r_2, &c., to be drawn with the means
at the draughtsman's disposal. Draw a curve as shown in fig. 72 with arcs
of the length l_1, l_2, l_3, &c., and with the radii r_1, r_2, &c. (note,
for a length ½l_1 at each end the radius will be infinite, and the curve
must end with a straight line tangent to the last arc), then let v be the
measured deflection of this curve from the straight line, and V the actual
deflection of the bridge; we have V = av/b, approximately. This method
distorts the curve, so that vertical ordinates of the curve are drawn to a
scale b times greater than that of the horizontal ordinates. Thus if the
horizontal scale be one-tenth of an inch to the foot, a = 120, and a beam
100 ft. in length would be drawn equal to 10 in.; then if the true radius
at the centre were 10,000 ft., this radius, if the curve were undistorted,
would be on paper 1000 in., but making b = 50 we can draw the curve with a
radius of 20 in. The vertical distortion of the curve must not be so great
that there is a very sensible difference between the length of the arc and
its chord. This can be regulated by altering the value of b. In fig. 72
distortion is carried too far; this figure is merely used as an
illustration.

38. _Camber._--In order that a girder may become straight under its working
load it should be constructed with a camber or upward convexity equal to
the calculated deflection. Owing to the yielding of joints when a beam is
first loaded a smaller modulus of elasticity should be taken than for a
solid bar. For riveted girders E is about 17,500,000 lb per sq. in. for
first loading. W.J.M. Rankine gives the approximate rule

Working deflection = [delta] = l²/10,000h,

where l is the span and h the depth of the beam, the stresses being those
usual in bridgework, due to the total dead and live load.

(W. C. U.)

[1] For the ancient bridges in Rome see further ROME: _Archaeology_, and
such works as R. Lanciani, _Ruins and Excavations of Ancient Rome_ (Eng.
trans., 1897), pp. 16 foll.

BRIDGET, SAINT, more properly BRIGID (c. 452-523), one of the patron saints
of Ireland, was born at Faughart in county Louth, her father being a prince
of Ulster. Refusing to marry, she chose a life of seclusion, making her
cell, the first in Ireland, under a large oak tree, whence the place was
called Kil-dara, "the church of the oak." The city of Kildare is supposed
to derive its name from St Brigid's cell. The year of her death is
generally placed in 523. She was buried at Kildare, but her remains were
afterwards translated to Downpatrick, where they were laid beside the
bodies of St Patrick and St Columba. Her feast is celebrated on the 1st of
February. A large collection of miraculous stories clustered round her
name, and her reputation was not confined to Ireland, for, under the name
of St Bride, she became a favourite saint in England, and numerous churches
were dedicated to her in Scotland.

See the five lives given in the Bollandist _Acta Sanctorum_, Feb. 1, i. 99,
119, 950. Cf. Whitley-Stokes, _Three Middle-Irish Homilies on the Lives of
Saint Patrick, Brigit and Columba_ (Calcutta, 1874); Colgan, _Acta SS.
Hiberniae_; D. O'Hanlon, _Lives of Irish Saints_, vol. ii.; Knowles, _Life
of St Brigid_ (1907); further bibliography in Ulysse Chevalier, _Répertoire
des sources hist. Bio.-Bibl._ (2nd ed., Paris, 1905), s.v.

BRIDGET, BRIGITTA, BIRGITTA, OF SWEDEN, SAINT (c. 1302-1373), the most
celebrated saint of the northern kingdoms, was the daughter of Birger
Persson, governor and _lagman_ (provincial judge) of Uppland, and one of
the richest landowners of the country. In 1316 she was married to Ulf
Gudmarson, lord of Nericia, to whom she bore eight children, one of whom
was [v.04 p.0557] afterwards honoured as St Catherine of Sweden. Bridget's
saintly and charitable life soon made her known far and wide; she gained,
too, great religious influence over her husband, with whom (1341-1343) she
went on pilgrimage to St James of Compostella. In 1344, shortly after their
return, Ulf died in the Cistercian monastery of Alvastra in East Gothland,
and Bridget now devoted herself wholly to religion. As a child she had
already believed herself to have visions; these now became more frequent,
and her records of these "revelations," which were translated into Latin by
Matthias, canon of Linköping, and by her confessor, Peter, prior of
Alvastra, obtained a great vogue during the middle ages. It was about this
time that she founded the order of St Saviour, or Bridgittines (_q.v._), of
which the principal house, at Vadstena, was richly endowed by King Magnus
II. and his queen. About 1350 she went to Rome, partly to obtain from the
pope the authorization of the new order, partly in pursuance of her
self-imposed mission to elevate the moral tone of the age. It was not till
1370 that Pope Urban V. confirmed the rule of her order; but meanwhile
Bridget had made herself universally beloved in Rome by her kindness and
good works. Save for occasional pilgrimages, including one to Jerusalem in
1373, she remained in Rome till her death on the 23rd of July 1373. She was
canonized in 1391 by Pope Boniface IX., and her feast is celebrated on the
9th of October.

BIBLIOGRAPHY.--Cf. the Bollandist _Acta Sanctorum_, Oct. 8, iv. 368-560;
the _Vita Sanctae Brigittae_, edited by C. Annerstedt in _Scriptores rerum
Suedicarum medii aevi_, iii. 185-244 (Upsala, 1871). The best modern work
on the subject is by the comtesse Catherine de Flavigny, entitled _Sainte
Brigitte de Suède, sa vie, ses révélations et son oeuvre_ (Paris, 1892),
which contains an exhaustive bibliography. The Revelations are contained in
the critical edition of St Bridget's works published by the Swedish
Historical Society and edited by G.E. Klemming (Stockholm, 1857-1884, II
vols.). For full bibliography (to 1904) see Ulysse Chevalier, _Répertoire
des sources hist. Bio.-Bibl._, _s.v._ "Brigitte."

BRIDGETON, a city, port of entry, and the county-seat of Cumberland county,
New Jersey, U.S.A., in the south part of the state, on Cohansey creek, 38
m. S. of Philadelphia. Pop. (1890) 11,424; (1900) 13,913, of whom 653 were
foreign-born and 701 were negroes; (1905) 13,624; (1910) 14,209. It is
served by the West Jersey & Sea Shore and the Central of New Jersey
railways, by electric railways connecting with adjacent towns, and by
Delaware river steamboats on Cohansey creek, which is navigable to this
point. It is an attractive residential city, has a park of 650 acres and a
fine public library, and is the seat of West Jersey academy and of Ivy
Hall, a school for girls. It is an important market town and distributing
centre for a rich agricultural region; among its manufactures are glass
(the product, chiefly glass bottles, being valued in 1905 at
$1,252,795--42.3% of the value of all the city's factory products--and
Bridgeton ranking eighth among the cities of the United States in this
industry), machinery, clothing, and canned fruits and vegetables; it also
has dyeing and finishing works. Though Bridgeton is a port of entry, its
foreign commerce is relatively unimportant. The first settlement in what is
now Bridgeton was made toward the close of the 18th century. A pioneer
iron-works was established here in 1814. The city of Bridgeton, formed by
the union of the township of Bridgeton and the township of Cohansey
(incorporated in 1845 and 1848 respectively), was chartered in 1864.

BRIDGETT, THOMAS EDWARD (1829-1899), Roman Catholic priest and historical
writer, was born at Derby on the 20th of January 1829. He was brought up a
Baptist, but in his sixteenth year joined the Church of England. In 1847 he
entered St John's College, Cambridge, with the intention of taking orders.
Being unable to subscribe to the Thirty-Nine Articles he could not take his
degree, and in 1850 became a Roman Catholic, soon afterwards joining the
Congregation of the Redemptorists. He went through his novitiate at St
Trond in Belgium, and after a course of five years of theological study at
Wittem, in Holland, was ordained priest. He returned to England in 1856,
and for over forty years led an active life as a missioner in England and
Ireland, preaching in over 80 missions and 140 retreats to the clergy and
to nuns. His stay in Limerick was particularly successful, and he founded a
religious confraternity of laymen which numbered 5000 members. Despite his
arduous life as a priest, Bridgett found time to produce literary works of
value, chiefly dealing with the history of the Reformation in England;
among these are _The Life of Blessed John Fisher, Bishop of Rochester_
(1888); _The Life and Writings of Sir Thomas More_ (1890); _History of the
Eucharist in Great Britain_ (2 vols., 1881); _Our Lady's Dowry_ (1875, 3rd
ed. 1890). He died at Clapham on the 17th of February 1899.

For a complete list of Bridgett's works see _The Life of Father Bridgett_,
by C. Ryder (London, 1906).

BRIDGEWATER, FRANCIS EGERTON, 3RD DUKE OF (1736-1803), the originator of
British inland navigation, younger son of the 1st duke, was born on the
21st of May 1736. Scroop, 1st duke of Bridgewater (1681-1745), was the son
of the 3rd earl of Bridgewater, and was created a duke in 1720; he was the
great-grandson of John Egerton, 1st earl of Bridgewater (d. 1649; cr.
1617), whose name is associated with the production of Milton's _Comus_;
and the latter was the son of Sir Thomas Egerton (1540-1617), Queen
Elizabeth's lord keeper and James I.'s lord chancellor, who was created
baron of Ellesmere in 1603, and in 1616 Viscount Brackley (_q.v._).

Francis Egerton succeeded to the dukedom at the age of twelve on the death
of his brother, the 2nd duke. As a child he was sickly and of such
unpromising intellectual capacity that at one time the idea of cutting the
entail was seriously entertained. Shortly after attaining his majority he
became engaged to the beautiful duchess of Hamilton, but her refusal to
give up the acquaintance of her sister, Lady Coventry, led to the breaking
off of the match. Thereupon the duke broke up his London establishment, and
retiring to his estate at Worsley, devoted himself to the making of canals.
The navigable canal from Worsley to Manchester which he projected for the
transport of the coal obtained on his estates was (with the exception of
the Sankey canal) the first great undertaking of the kind executed in Great
Britain in modern times. The construction of this remarkable work, with its
famous aqueduct across the Irwell, was carried out by James Brindley, the
celebrated engineer. The completion of this canal led the duke to undertake
a still more ambitious work. In 1762 he obtained parliamentary powers to
provide an improved waterway between Liverpool and Manchester by means of a
canal. The difficulties encountered in the execution of the latter work
were still more formidable than those of the Worsley canal, involving, as
they did, the carrying of the canal over Sale Moor Moss. But the genius of
Brindley, his engineer, proved superior to all obstacles, and though at one
period of the undertaking the financial resources of the duke were almost
exhausted, the work was carried to a triumphant conclusion. The untiring
perseverance displayed by the duke in surmounting the various difficulties
that retarded the accomplishment of his projects, together with the
pecuniary restrictions he imposed on himself in order to supply the
necessary capital (at one time he reduced his personal expenses to £400 a
year), affords an instructive example of that energy and self-denial on
which the success of great undertakings so much depends. Both these canals
were completed when the duke was only thirty-six years of age, and the
remainder of his life was spent in extending them and in improving his
estates; and during the latter years of his life he derived a princely
income from the success of his enterprise. Though a steady supporter of
Pitt's administration, he never took any prominent part in politics.

He died unmarried on the 8th of March 1803, when the ducal title became
extinct, but the earldom of Bridgewater passed to a cousin, John William
Egerton, who became 7th earl. By his will he devised his canals and estates
on trust, under which his nephew, the marquess of Stafford (afterwards
first duke of Sutherland), became the first beneficiary, and next his son
Francis Leveson Gower (afterwards first earl of Ellesmere) and his issue.
In order that the trust should last as long as possible, an extraordinary
use was made of the legal rule that property may be [v.04 p.0558] settled
for the duration of lives in being and twenty-one years after, by choosing
a great number of persons connected with the duke and their living issue
and adding to them the peers who had taken their seats in the House of
Lords on or before the duke's decease. Though the last of the peers died in
1857, one of the commoners survived till the 19th of October 1883, and
consequently the trust did not expire till the 19th of October 1903, when
the whole property passed under the undivided control of the earl of
Ellesmere. The canals, however, had in 1872 been transferred to the
Bridgewater Navigation Company, by whom they were sold in 1887 to the
Manchester Ship Canal Company.

BRIDGEWATER, FRANCIS HENRY EGERTON, 8TH EARL OF (1756-1829), was educated
at Eton and Christ Church, Oxford, and became fellow of All Souls in 1780,
and F.R.S. in 1781. He held the rectories of Middle and Whitchurch in
Shropshire, but the duties were performed by a proxy. He succeeded his
brother (see above) in the earldom in 1823, and spent the latter part of
his life in Paris. He was a fair scholar, and a zealous naturalist and
antiquarian. When he died in February 1829 the earldom became extinct. He
bequeathed to the British Museum the valuable Egerton MSS. dealing with the
literature of France and Italy, and also £12,000. He also left £8000 at the
disposal of the president of the Royal Society, to be paid to the author or
authors who might be selected to write and publish 1000 copies of a
treatise "On the Power, Wisdom and Goodness of God, as manifested in the
Creation." Mr Davies Gilbert, who then filled the office, selected eight
persons, each to undertake a branch of this subject, and each to receive
£1000 as his reward, together with any benefit that might accrue from the
sale of his work, according to the will of the testator.

The Bridgewater treatises were published as follows:--1. _The Adaptation of
External Nature to the Moral and Intellectual Condition of Man_, by Thomas
Chalmers, D.D. 2. _The Adaptation of External Nature to the Physical
Condition of Man_, by John Kidd, M.D. 3. _Astronomy and General Physics
considered with reference to Natural Theology_, by William Whewell, D.D. 4.
_The Hand, its Mechanism and Vital Endowments as evincing Design_, by Sir
Charles Bell. 5. _Animal and Vegetable Physiology considered with reference
to Natural Theology_, by Peter Mark Roget. 6. _Geology and Mineralogy
considered with reference to Natural Theology_, by William Buckland, D.D.
7. _The Habits and Instincts of Animals with reference to Natural
Theology_, by William Kirby. 8. _Chemistry, Meteorology, and the Function
of Digestion, considered with reference to Natural Theology_, by William
Prout, M.D. The works are of unequal merit; several of them took a high
rank in apologetic literature. They first appeared during the years 1833 to
1840, and afterwards in Bohn's Scientific Library.

BRIDGITTINES, an order of Augustinian canonesses founded by St Bridget of
Sweden (_q.v._) c. 1350, and approved by Urban V. in 1370. It was a "double
order," each convent having attached to it a small community of canons to
act as chaplains, but under the government of the abbess. The order spread
widely in Sweden and Norway, and played a remarkable part in promoting
culture and literature in Scandinavia; to this is to be attributed the fact
that the head house at Vastein, by Lake Vetter, was not suppressed till
1595. There were houses also in other lands, so that the total number
amounted to 80. In England, the famous Bridgittine convent of Syon at
Isleworth, Middlesex, was founded and royally endowed by Henry V. in 1415,
and became one of the richest and most fashionable and influential
nunneries in the country. It was among the few religious houses restored in
Mary's reign, when nearly twenty of the old community were re-established
at Syon. On Elizabeth's accession they migrated to the Low Countries, and
thence, after many vicissitudes, to Rouen, and finally in 1594 to Lisbon.
Here they remained, always recruiting their numbers from England, till
1861, when they returned to England. Syon House is now established at
Chudleigh in Devon, the only English community that can boast an unbroken
conventual existence since pre-Reformation times. Some six other
Bridgittine convents exist on the Continent, but the order is now composed
only of women.

See Helyot, _Histoire des ordres religieux_ (1715), iv. c. 4; Max
Heimbucher, _Orden u. Kongregationen_ (1907), ii. § 83; Herzog-Hauck,
_Realencyklopädie_ (ed. 3), art. "Birgitta"; A. Hamilton in _Dublin
Review_, 1888, "The Nuns of Syon."

(E. C. B.)

BRIDGMAN, FREDERICK ARTHUR (1847- ), American artist, was born at Tuskegee,
Alabama, on the 10th of November 1847. He began as a draughtsman in New
York for the American Bank Note Company in 1864-1865, and studied art in
the same years at the Brooklyn Art School and at the National Academy of
Design; but he went to Paris in 1866 and became a pupil of J.L. Gérôme.
Paris then became his headquarters. A trip to Egypt in 1873-1874 resulted
in pictures of the East that attracted immediate attention, and his large
and important composition, "The Funeral Procession of a Mummy on the Nile,"
in the Paris Salon (1877), bought by James Gordon Bennett, brought him the
cross of the Legion of Honour. Other paintings by him were "An American
Circus in Normandy," "Procession of the Bull Apis" (now in the Corcoran Art
Gallery, Washington), and a "Rumanian Lady" (in the Temple collection,
Philadelphia).

BRIDGMAN, LAURA DEWEY (1829-1889), American blind deaf-mute, was born on
the 21st of December 1829 at Hanover, New Hampshire, U.S.A., being the
third daughter of Daniel Bridgman (d. 1868), a substantial Baptist farmer,
and his wife Harmony, daughter of Cushman Downer, and grand-daughter of
Joseph Downer, one of the five first settlers (1761) of Thetford, Vermont.
Laura was a delicate infant, puny and rickety, and was subject to fits up
to twenty months old, but otherwise seemed to have normal senses; at two
years, however, she had a very bad attack of scarlet fever, which destroyed
sight and hearing, blunted the sense of smell, and left her system a wreck.
Though she gradually recovered health she remained a blind deaf-mute, but
was kindly treated and was in particular made a sort of playmate by an
eccentric bachelor friend of the Bridgmans, Mr Asa Tenney, who as soon as
she could walk used to take