[1] During the captivity of Bohemund III. the patriarch of Antioch
helped to found a commune, which persisted, with its mayor and
_jurats_, during the 13th century.
BOHMER, JOHANN FRIEDRICH (1795-1863), German historian, son of Karl
Ludwig Bohmer (d. 1817), was born at Frankfort-on-Main on the 22nd of
April 1795. Educated at the universities of Heidelberg and Gottingen, he
showed an interest in art and visited Italy; but returning to Frankfort
he turned his attention to the study of history, and became secretary
of the _Gesellschaft fur altere deutsche Geschichtskunde_. He was also
archivist and then librarian of the city of Frankfort. Bohmer had a
great dislike of Prussia and the Protestant faith, and a corresponding
affection for Austria and the Roman Catholic Church, to which, however,
he did not belong. His critical sense was, perhaps, somewhat warped; but
his researches are of great value to students. He died unmarried, at
Frankfort, on the 22nd of October 1863. Bohmer's historical work was
chiefly concerned with collecting and tabulating charters and other
imperial documents of the middle ages. First appeared an abstract, the
_Regesta chronologico-diplomatica regum atque imperatorum Romanorum
911-1313_ (Frankfort, 1831), which was followed by the _Regesta
chronologico-diplomatica Karolorum. Die Urkunden samtlicher Karolinger
in kurzen Auszugen_ (Frankfort, 1833), and a series of _Regesta
imperii_. For the period 1314-1347 (Frankfort, 1839) the _Regesta_ was
followed by three, and for the period 1246-1313 (Frankfort, 1844) by two
supplementary volumes. The remaining period of the _Regesta_, as edited
by Bohmer, is 1198-1254 (Stuttgart, 1849). These collections contain
introductions and explanatory passages by the author. Very valuable also
is the _Fontes rerum Germanicarum_ (Stuttgart, 1843-1868), a collection
of original authorities for German history during the 13th and 14th
centuries. The fourth and last volume of this work was edited by A.
Huber after the author's death. Other collections edited by Bohmer are:
_Die Reichsgesetze 900-1400_ (Frankfort, 1832); _Wittelsbachische
Regesten von der Erwerbung des Herzogtums Bayern bis zu 1340_
(Stuttgart, 1854); and _Codex diplomaticus Moeno-Francofurtanus.
Urkundenbuch der Reichsstadt Frankfurt_ (Frankfort, 1836; new edition by
F. Law, 1901). Other volumes and editions of the _Regesta imperii_,
edited by J. Ficker, E. Muhlbacher, E. Winkelmann and others, are
largely based on Bohmer's work. Bohmer left a great amount of
unpublished material, and after his death two other works were published
from his papers: _Acta imperii selecta_, edited by J. Ficker (Innsbruck,
1870); and _Regesta archiepiscoporum Maguntinensium_, edited by C. Will
(Innsbruck, 1877-1886).
See J. Janssen, _J.F. Bohmers Leben, Briefe und kleinere Schriften_
(Freiburg, 1868).
BOHN, HENRY GEORGE (1796-1884), British publisher, son of a German
bookbinder settled in England, was born in London on the 4th of January
1796. In 1831 he started as a dealer in rare books and "remainders." In
1841 he issued his "Guinea" Catalogue of books, a monumental work
containing 23,208 items. Bohn was noted for his book auction sales: one
held in 1848 lasted four days, the catalogue comprising twenty folio
pages. Printed on this catalogue was the information: "Dinner at 2
o'clock, dessert at 4, tea at 5, and supper at 10." The name of Bohn is
principally remembered by the important _Libraries_ which he
inaugurated: these were begun in 1846 and comprised editions of standard
works and translations, dealing with history, science, classics,
theology and archaeology, consisting in all of 766 volumes. One of
Bohn's most useful and laborious undertakings was his revision (6 vols.
1864) of _The Bibliographer's Manual of English Literature_ (1834) of
W.T. Lowndes. The plan includes bibliographical and critical notices,
particulars of prices, &c., and a considerable addition to the original
work. It had been one of Bohn's ambitions to found a great publishing
house, but, finding that his sons had no taste for the trade, he sold
the _Libraries_ in 1864 to Messrs. Bell and Daldy, afterwards G. Bell &
Sons. Bohn was a man of wide culture and many interests. He himself made
considerable contributions to his _Libraries_: he collected pictures,
china and ivories, and was a famous rose-grower. He died at Twickenham
on the 22nd of August 1884.
BOHTLINGK, OTTO VON (1815-1004) German Sanskrit scholar, was born on the
30th of May (11th of June O.S.) 1815 at St Petersburg. Having studied
(1833-1835) Oriental languages, particularly Arabic, Persian and
Sanskrit, at the university of St Petersburg, he continued his studies
in Germany, first in Berlin and then (1839-1842) in Bonn. Returning to
St Petersburg in 1842, he was attached to the Royal Academy of Sciences,
and was elected an ordinary member of that society in 1855. In 1860 he
was made "Russian state councillor," and later "privy councillor" with a
title of nobility. In 1868 he settled at Jena, and in 1885 removed to
Leipzig, where he resided until his death there on the 1st of April
1904. Bohtlingk was one of the most distinguished scholars of the 19th
century, and his works are of pre-eminent value in the field of Indian
and comparative philology. His first great work was an edition of
Panini's _Acht Bucher grammatischer Regeln_ (Bonn, 1839-1840), which was
in reality a criticism of Franz Bopp's philological methods. This book
Bohtlingk again took up forty-seven years later, when he republished it
with a complete translation under the title _Paninis Grammatik mit
Ubersetzung_ (Leipzig, 1887). The earlier edition was followed by
_Vopadevas Grammatik_ (St Petersburg, 1847); _Uber die Sprache der
Jakuten_ (St Petersburg, 1851); _Indische Spruche_ (2nd ed. in 3 parts,
St Petersburg, 1870-1873, to which an index was published by Blau,
Leipzig, 1893); a critical examination and translation of
_Chhandogya-upanishad (St Petersburg, 1889) and a translation of
Brihadaranyaka-upanishad_ (St Petersburg, 1889). In addition to these he
published several smaller treatises, notably one on the Sanskrit
accents, _Uber den Accent im Sanskrit_ (1843). But his _magnum opus_ is
his great Sanskrit dictionary, _Sanskrit-Worterbuch_ (7 vols., St
Petersburg, 1853-1875; new ed. 7 vols., St Petersburg, 1879-1889), which
with the assistance of his two friends, Rudolf Roth (1821-1895) and
Albrecht Weber (b. 1825), was completed in twenty-three years.
BOHUN, the name of a family which plays an important part in English
history during the 13th and 14th centuries; it was taken from a village
situated in the Cotentin between Coutances and the estuary of the Vire.
The Bohuns came into England at, or shortly after, the Norman Conquest;
but their early history there is obscure. The founder of their greatness
was Humphrey III., who in the latter years of Henry I., makes his
appearance as a _dapifer_, or steward, in the royal household. He
married the daughter of Milo of Gloucester, and played an ambiguous part
in Stephen's reign, siding at first with the king and afterwards with
the empress. Humphrey III. lived until 1187, but his history is
uneventful. He remained loyal to Henry II. through all changes, and
fought in 1173 at Farnham against the rebels of East Anglia. Outliving
his eldest son, Humphrey IV., he was succeeded in the family estates by
his grandson Henry. Henry was connected with the royal house of Scotland
through his mother Margaret, a sister of William the Lion; an alliance
which no doubt assisted him to obtain the earldom of Hereford from John
(1199). The lands of the family lay chiefly on the Welsh Marches, and
from this date the Bohuns take a foremost place among the Marcher
barons. Henry de Bohun figures with the earls of Clare and Gloucester
among the twenty-five barons who were elected by their fellows to
enforce the terms of the Great Charter. In the subsequent civil war he
fought on the side of Louis, and was captured at the battle of Lincoln
(1217). He took the cross in the same year and died on his pilgrimage
(June 1, 1220). Humphrey V., his son and heir, returned to the path of
loyalty, and was permitted, some time before 1239, to inherit the
earldom of Essex from his maternal uncle, William de Mandeville. But in
1258 this Humphrey fell away, like his father, from the royal to the
baronial cause. He served as a nominee of the opposition on the
committee of twenty-four which was appointed, in the Oxford parliament
of that year, to reform the administration. It was only the alliance of
Montfort with Llewelyn of North Wales that brought the earl of Hereford
back to his allegiance. Humphrey V. headed the first secession of the
Welsh Marchers from the party of the opposition (1263), and was amongst
the captives whom the Montfortians took at Lewes. The earl's son and
namesake was on the victorious side, and shared in the defeat of
Evesham, which he did not long survive. Humphrey V. was, therefore,
naturally selected as one of the twelve arbitrators to draw up the ban
of Kenilworth (1266), by which the disinherited rebels were allowed to
make their peace. Dying in 1275, he was succeeded by his grandson
Humphrey VII. This Bohun lives in history as one of the recalcitrant
barons of the year 1297, who extorted from Edward I. the _Confirmatio
Cartarum_. The motives of the earl's defiance were not altogether
disinterested. He had suffered twice from the chicanery of Edward's
lawyers; in 1284 when a dispute between himself and the royal favourite,
John Giffard, was decided in the latter's favour; and again in 1292 when
he was punished with temporary imprisonment and sequestration for a
technical, and apparently unwitting, contempt of the king's court. In
company, therefore, with the earl of Norfolk he refused to render
foreign service in Gascony, on the plea that they were only bound to
serve with the king, who was himself bound for Flanders. Their attitude
brought to a head the general discontent which Edward had excited by his
arbitrary taxation; and Edward was obliged to make a surrender on all
the subjects of complaint. At Falkirk (1298) Humphrey VII. redeemed his
character for loyalty. His son, Humphrey VIII., who succeeded him in the
same year, was allowed to marry one of the king's daughters, Eleanor,
the widowed countess of Holland (1302). This close connexion with the
royal house did not prevent him, as it did not prevent Earl Thomas of
Lancaster, from joining the opposition to the feeble Edward II. In 1310
Humphrey VIII. figured among the Lords Ordainers; though, with more
patriotism than some of his fellow-commissioners, he afterwards followed
the king to Bannockburn. He was taken captive in the battle, but
exchanged for the wife of Robert Bruce. Subsequently he returned to the
cause of his order, and fell on the side of Earl Thomas at the field of
Boroughbridge (1322). With him, as with his father, the politics of the
Marches had been the main consideration; his final change of side was
due to jealousy of the younger Despenser, whose lordship of Glamorgan
was too great for the comfort of the Bohuns in Brecon. With the death of
Humphrey VIII. the fortunes of the family enter on a more peaceful
stage. Earl John (d. 1335) was inconspicuous; Humphrey IX. (d. 1361)
merely distinguished himself as a captain in the Breton campaigns of the
Hundred Years' War, winning the victories of Morlaix (1342) and La Roche
Derrien (1347). His nephew and heir, Humphrey X., who inherited the
earldom of Northampton from his father, was territorially the most
important representative of the Bohuns. But the male line was
extinguished by his death (1373). The three earldoms and the broad lands
of the Bohuns were divided between two co-heiresses. Both married
members of the royal house. The elder, Eleanor, was given in 1374 to
Thomas of Woodstock, seventh son of Edward III.; the younger, Mary, to
Henry, earl of Derby, son of John of Gaunt and afterwards Henry IV., in
1380 or 1381. From these two marriages sprang the houses of Lancaster
and Stafford.
See J.E. Doyle's _Official Baronage of England_ (1886), the _Complete
Peerage_ of G. E. C(okayne), (1867-1898); T.F. Tout's "Wales and the
March during the Barons' War," in Owens College Historical Essays, pp.
87-136 (1902); J.E. Morris' _Welsh Wars of King Edward I._, chs. vi.,
viii. (1901). (H. W. C. D.)
BOIARDO, MATTEO MARIA, COUNT (1434-1404), Italian poet, who came of a
noble and illustrious house established at Ferrara, but originally from
Reggio, was born at Scandiano, one of the seignorial estates of his
family, near Reggio di Modena, about the year 1434, according to
Tiraboschi, or 1420 according to Mazzuchelli. At an early age he entered
the university of Ferrara, where he acquired a good knowledge of Greek
and Latin, and even of the Oriental languages, and was in due time
admitted doctor in philosophy and in law. At the court of Ferrara, where
he enjoyed the favour of Duke Borso d'Este and his successor Hercules,
he was entrusted with several honourable employments, and in particular
was named governor of Reggio, an appointment which he held in the year
1478. Three years afterwards he was elected captain of Modena, and
reappointed governor of the town and citadel of Reggio, where he died in
the year 1494, though in what month is uncertain.
Almost all Boiardo's works, and especially his great poem of the
_Orlando Inamorato_, were composed for the amusement of Duke Hercules
and his court, though not written within its precincts. His practice, it
is said, was to retire to Scandiano or some other of his estates, and
there to devote himself to composition; and Castelvetro, Vallisnieri,
Mazzuchelli and Tiraboschi all unite in stating that he took care to
insert in the descriptions of his poem those of the agreeable environs
of his chateau, and that the greater part of the names of his heroes, as
Mandricardo, Gradasse, Sacripant, Agramant and others, were merely the
names of some of his peasants, which, from their uncouthness, appeared
to him proper to be given to Saracen warriors. Be this as it may, the
_Orlando Inamorato_ deserves to be considered as one of the most
important poems in Italian literature, since it forms the first example
of the romantic epic worthy to serve as a model, and, as such,
undoubtedly produced Ariosto's _Orlando Furioso_. Gravina and Mazzuchell
have said, and succeeding writers have repeated on their authority, that
Boiardo proposed to himself as his model the _Iliad_ of Homer; that
Paris is besieged like the city of Troy; that Angelica holds the place
of Helen; and that, in short, the one poem is a sort of reflex image of
the other. In point of fact, however, the subject-matter of the poem is
derived from the _Fabulous Chronicle_ of the pseudo-Turpin; though, with
the exception of the names of Charlemagne, Roland, Oliver, and some
other principal warriors, who necessarily figure as important characters
in the various scenes, there is little resemblance between the detailed
plot of the one and that of the other. The poem, which Boiardo did not
live to finish, was printed at Scandiano the year after his death, under
the superintendence of his son Count Camillo. The title of the book is
without date; but a Latin letter from Antonia Caraffa di Reggio,
prefixed to the poem, is dated the kalends of June 1495. A second
edition, also without date, but which must have been printed before the
year 1500, appeared at Venice; and the poem was twice reprinted there
during the first twenty years of the 16th century. These editions are
the more curious and valuable since they contain nothing but the text of
the author, which is comprised in three books, divided into cantos, the
third book being incomplete. But Niccolo degli Agostini, an indifferent
poet, had the courage to continue the work commenced by Boiardo, adding
to it three books, which were printed at Venice in 1526-1531, in 4to;
and since that time no edition of the _Orlando_ has been printed without
the continuation of Agostini, wretched as it unquestionably is.
Boiardo's poem suffers from the incurable defect of a laboured and heavy
style. His story is skilfully constructed, the characters are well drawn
and sustained throughout; many of the incidents show a power and
fertility of imagination not inferior to that of Ariosto, but the
perfect workmanship indispensable for a great work of art is wanting.
The poem in its original shape was not popular, and has been completely
superseded by the _Rifacimento_ of Francesco Berni (q.v.).
The other works of Boiardo are--(1) _Il Timone_, a comedy, Scandiano,
1500, 4to; (2) _Sonnetti e Canzoni_, Reggio, 1499, 4to; (3) _Carmen
Bucolicon_, Reggio, 1500, 4to; (4) _Cinque Capitoli in terza rima_,
Venice, 1523 or 1533; (5) _Apulejo dell' Asino d'Oro_, Venice, 1516,
1518; (6) _Asino d'Oro de Luciano tradolto in volgare_, Venice, 1523,
8vo; (7) _Erodoto Alicarnasseo istorico, tradotto di Greco in Lingua
Italiana_, Venice, 1533 and 1538, 8vo; (8) _Rerum Italicarum
Scriptores_.
See Panizzi's _Boiardo_ (9 vols., 1830-1831).
BOIE, HEINRICH CHRISTIAN (1744-1806), German author, was born at Meldorf
in the then Danish province of Schleswig-Holstein on the 19th of July
1744. After studying law at Jena, he went in 1769 to Gottingen, where he
became one of the leading spirits in the Gottingen "Dichterbund" or
"Hain." Boie's poetical talent was not great, but his thorough knowledge
of literature, his excellent taste and sound judgment, made him an ideal
person to awake the poetical genius of others. Together with F.W. Gotter
(q.v.) he founded in 1770 the Gottingen _Musenalmanach_, which he
directed and edited until 1775, when, in conjunction with C.W. von Dohm
(1751-1820), he brought out _Das deutsche Museum_, which became one of
the best literary periodicals of the day. In 1776 Boie became secretary
to the commander-in-chief at Hanover, and in 1781 was appointed
administrator of the province of Suderditmarschen in Holstein. He died
at Meldorf on the 3rd of March 1806.
See K. Weinhold, _Heinrich Christian Boie_ (Halle, 1868).
BOIELDIEU, FRANCOIS ADRIEN (1775-1834), French composer of comic opera,
was born at Rouen on the 15th of December 1775. He received his first
musical education from M. Broche, the cathedral organist, who appears to
have treated him very harshly. He began composing songs and chamber
music at a very early age-his first opera, _La Fille coupable_ (the
libretto by his father), and his second opera, _Rosalie et Myrza_, being
produced on the stage of Rouen in 1795. Not satisfied with his local
success he went to Paris in 1795. His scores were submitted to
Cherubini, Mehul and others, but met with little approbation. Grand
opera was the order of the day. Boieldieu had to fall back on his talent
as a pianoforte-player for a livelihood. Success came at last from an
unexpected source. P.J. Garat, a fashionable singer of the period,
admired Boieldleu's touch on the piano, and made him his accompanist. In
the drawing-rooms of the Directoire Garat sang the charming songs and
ballads with which the young composer supplied him. Thus Boieldieu's
reputation gradually extended to wider circles. In 1796 _Les Deux
lettres_ was produced, and in 1797 _La Famille suisse_ appeared for the
first time on a Paris stage, and was well received. Several other operas
followed in rapid succession, of which only _Le Calife de Bagdad_ (1800)
has escaped oblivion. After the enormous success of this work, Boieldieu
felt the want of a thorough musical training and took lessons from
Cherubini, the influence of that great master being clearly discernible
in the higher artistic finish of his pupil's later compositions. In 1802
Boieldieu, to escape the domestic troubles caused by his marriage with
Clotilde Aug. Mafleuroy, a celebrated ballet-dancer of the Paris opera,
took flight and went to Russia, where he was received with open arms by
the emperor Alexander. During his prolonged stay at St Petersburg he
composed a number of operas. He also set to music the choruses of
Racine's _Athalie_, one of his few attempts at the tragic style of
dramatic writing. In 1811 he returned to his own country, where the
following year witnessed the production of one of his finest works,
_Jean de Paris_, in which he depicted with much felicity the charming
coquetry of the queen of Navarre, the chivalrous _verve_ of the king,
the officious pedantry of the seneschal, and the amorous tenderness of
the page. He succeeded Mehul as professor of composition at the
Conservatoire in 1817. _Le Chapeau rouge_ was produced with great
success in 1818. Boieldieu's second and greatest masterpiece was his
_Dame blanche_ (1825). The libretto, written by Scribe, was partly
suggested by Walter Scott's _Monastery_, and several original Scottish
tunes cleverly introduced by the composer add to the melodious charm and
local colour of the work. On the death of his wife in 1825, Boieldieu
married a singer. His own death was due to a violent attack of pulmonary
disease. He vainly tried to escape the rapid progress of the illness by
travel in Italy and the south of France, but returned to Paris only to
die on the 8th of October 1834.
Lives of Boieldieu have been written by Pougin (Paris, 1875), J.A.
Refeuvaille (Rouen, 1836), Hequet (Paris, 1864), Emile Duval (Geneva,
1883). See also Adolphe Charles Adam, _Derniers souvenirs d'un
musicien_.
BOIGNE, BENOIT DE, COUNT (1751-1830), the first of the French military
adventurers in India, was born at Chambery in Savoy on the 8th of March
1751, being the son of a fur merchant. He joined the Irish Brigade in
France in 1768, and subsequently he entered the Russian service and was
captured by the Turks. Hearing of the wealth of India, he made his way
to that country, and after serving for a short time in the East India
Company, he resigned and joined Mahadji Sindhia in 1784 for the purpose
of training his troops in the European methods of war. In the battles of
Lalsot and Chaksana Boigne and his two battalions proved their worth by
holding the field when the rest of the Mahratta army was defeated by the
Rajputs. In the battle of Agra (1788) he restored the Mahratta fortunes,
and made Mahadji Sindhia undisputed master of Hindostan. This success
led to his being given the command of a brigade of ten battalions of
infantry, with which he won the victories of Patan and Merta in 1790. In
consequence Boigne was allowed to raise two further brigades of
disciplined infantry, and made commander-in-chief of Sindhia's army. In
the battle of Lakhairi (1793) he defeated Holkar's army. On the death of
Mahadji Sindhia in 1794, Boigne could have made himself master of
Hindostan had he wished it, but he remained loyal to Daulat Rao Sindhia.
In 1795 his health began to fail, and he resigned his command, and in
the following year returned to Europe with a fortune of L400,000. He
lived in retirement during the lifetime of Napoleon, but was greatly
honoured by Louis XVIII. He died on the 21st of June 1830.
See H. Compton, _European Military Adventurers of Hindustan_ (1892).
BOII (perhaps = "the terrible"), a Celtic people, whose original home
was Gallia Transalpina. They were known to the Romans, at least by name,
in the time of Plautus, as is shown by the contemptuous reference in the
_Captivi_ (888). At an early date they split up into two main groups,
one of which made its way into Italy, the other into Germany. Some,
however, appear to have stayed behind, since, during the Second Punic
War, Magalus, a Boian prince, offered to show Hannibal the way into
Italy after he had crossed the Pyrenees (Livy xxi. 29). The first group
of immigrants is said to have crossed the Pennine Alps (Great St
Bernard) into the valley of the Po. Finding the district already
occupied, they proceeded over the river, drove out the Etruscans and
Umbrians, and established themselves as far as the Apennines in the
modern Romagna. According to Cato (in Pliny, _Nat. Hist._ iii. 116) they
comprised as many as 112 different tribes, and from the remains
discovered in the tombs at Hallstatt, La Tene and other places, they
appear to have been fairly civilized. Several wars took place between
them and the Romans. In 283 they were defeated, together with the
Etruscans, at the Vadimonian lake; in 224, after the battle of Telamon
in Etruria, they were forced to submit. But they still cherished a
hatred of the Romans, and during the Second Punic War (218), irritated
by the foundation of the Roman colonies of Cremona and Placentia, they
rendered valuable assistance to Hannibal. They continued the struggle
against Rome from 201 to 191, when they were finally subdued by P.
Cornelius Scipio Nasica, and deprived of nearly half their territory.
According to Strabo (v. p. 213) the Boii were driven back across the
Alps and settled on the land of their kinsmen, the Taurisci, on the
Danube, adjoining Vindelicia and Raetia. Most authorities, however,
assume that there had been a settlement of the Boii on the Danube from
very early times, in part of the modern Bohemia (anc. _Boiohemum_, "land
of the Boii"). About 60 B.C. some of the Boii migrated to Noricum and
Pannonia, when 32,000 of them joined the expedition of the Helvetians
into Gaul, and shared their defeat near Bibracte (58). They were
subsequently allowed by Caesar to settle in the territory of the Aedui
between the Loire and the Allier. Their chief town was Gorgobina (site
uncertain). Those who remained on the Danube were exterminated by the
Dacian king, Boerebista, and the district they had occupied was
afterwards called the "desert of the Boii" (Strabo vii. p. 292). In A.D.
69 a Boian named Mariccus stirred up a fanatical revolt, but was soon
defeated and put to death. Some remnants of the Boii are mentioned as
dwelling near Bordeaux; but Mommsen inclines to the opinion that the
three groups (in Bordeaux, Bohemia and the Po districts) were not really
scattered branches of one and the same stock, but that they are
instances of a mere similarity of name.
The Boii, as we know them, belonged almost certainly to the Early Iron
age. They probably used long iron swords for dealing cutting blows, and
from the size of the handles they must have been a race of large men
(cf. Polybius ii. 30). For their ethnological affinities and especially
their possible connexion with the Homeric Achaeans see W. Ridgeway's
_Early Age of Greece_ (vol. i., 1901).
See L. Contzen, _Die Wanderungen der Kelten_ (Leipzig, 1861); A.
Desjardins, _Geographie historique de la Gaule romaine_, ii.
(1876-1893); T.R. Holmes, _Caesar's Conquest of Gaul_ (1899), pp.
426-428; T. Mommsen, _Hist. of Rome_, ii. (Eng. trans. 5 vols., 1894),
p. 373 note; M. Ihm in Pauly-Wissowa's _Realencyclopadie_, iii. pt. 1
(1897); A. Holder, _Alt-celtischer Sprachschatz_.
BOIL, in medicine, a progressive local inflammation of the skin, taking
the form of a hard suppurating tumour, with a core of dead tissue,
resulting from infection by a microbe, _Staphylococcus pyogenes_, and
commonly occurring in young persons whose blood is disordered, or as a
complication in certain diseases. Treatment proceeds on the lines of
bringing the mischief out, assisting the evacuation of the boil by the
lancet, and clearing the system. In the English Bible, and also in
popular medical terminology, "boil" is used of various forms of ulcerous
affection. The boils which were one of the plagues in Egypt were
apparently the bubonic plague. The terms Aleppo boil (or button), Delhi
boil, Oriental boil, Biskra button, &c., have been given to a tropical
epidemic, characterized by ulcers on the face, due to a diplococcus
parasite.
BOILEAU-DESPREAUX, NICOLAS (1636-1711), French poet and critic, was born
on the 1st of November 1636 in the rue de Jerusalem, Paris. The same
Despreaux was derived from a small property at Crosne near Villeneuve
Saint-Georges. He was the fifteenth child of Gilles Boileau, a clerk in
the parlement. Two of his brothers attained some distinction: Gilles
Boileau (1631-1669), the author of a translation of Epictetus; and
Jacques Boileau, who became a canon of the Sainte-Chapelle, and made
valuable contributions to church history. His mother died when he was
two years old; and Nicolas Boileau, who had a delicate constitution,
seems to have suffered something from want of care. Sainte-Beuve puts
down his somewhat hard and unsympathetic outlook quite as much to the
uninspiring circumstances of these days as to the general character of
his time. He cannot be said to have been early disenchanted, for he
never seems to have had any illusions; he grew up with a single passion,
"the hatred of stupid books." He was educated at the College de
Beauvais, and was then sent to study theology at the Sorbonne. He
exchanged theology for law, however, and was called to the bar on the
4th of December 1656. From the profession of law, after a short trial,
he recoiled in disgust, complaining bitterly of the amount of chicanery
which passed under the name of law and justice. His father died in 1657,
leaving him a small fortune, and thenceforward he devoted himself to
letters.
Such of his early poems as have been preserved hardly contain the
promise of what he ultimately became. The first piece in which his
peculiar powers were displayed was the first satire (1660), in imitation
of the third satire of Juvenal; it embodied the farewell of a poet to
the city of Paris. This was quickly followed by eight others, and the
number was at a later period increased to twelve. A twofold interest
attaches to the satires. In the first place the author skilfully
parodies and attacks writers who at the time were placed in the very
first rank, such as Jean Chapelain, the abbe Charles Cotin, Philippe
Quinault and Georges de Scudery; he openly raised the standard of revolt
against the older poets. But in the second place he showed both by
precept and practice what were the poetical capabilities of the French
language. Prose in the hands of such writers as Descartes and Pascal had
proved itself a flexible and powerful instrument of expression, with a
distinct mechanism and form. But except with Malherbe, there had been no
attempt to fashion French versification according to rule or method. In
Boileau for the first time appeared terseness and vigour of expression,
with perfect regularity of verse structure. His admiration for Moliere
found expression in the stanzas addressed to him (1663), and in the
second satire (1664). In 1664 he composed his prose _Dialogue des heros
de roman_, a satire on the elaborate romances of the time, which may be
said to have once for all abolished the lucubrations of La Calprenede,
Mlle de Scudery and their fellows. Though fairly widely read in
manuscript, the book was not published till 1713, out of regard, it is
said, for Mlle de Scudery. To these early days belong the reunions at
the _Moulon Blanc_ and the _Pomme du Pin_, where Boileau, Moliere,
Racine, Chapelle and Antoine Furetiere met to discuss literary
questions. To Moliere and Racine he proved a constant friend, and
supported their interests on many occasions.
In 1666, prompted by the publication of two unauthorized editions, he
published _Satires du Sieur D...._, containing seven satires and the
_Discours au roi_. From 1669 onwards appeared his epistles, graver in
tone than the satires, maturer in thought, more exquisite and polished
in style. The _Epitres_ gained for him the favour of Louis XIV., who
desired his presence at court. The king asked him which he thought his
best verses. Whereupon Boileau diplomatically selected as his "least
bad" some still unprinted lines in honour of the grand monarch and
proceeded to recite them. He received forthwith a pension of 2000
livres. In 1674 his two masterpieces, _L'Art poetique_ and _Le Lutrin_,
were published with some earlier works as the _Oeuvres diverses du sieur
D_.... The first, in imitation of the _Ars Poetica_ of Horace, lays down
the code for all future French verse, and may be said to fill in French
literature a parallel place to that held by its prototype in Latin. On
English literature the maxims of Boileau, through the translation
revised by Dryden, and through the magnificent imitation of them in
Pope's _Essay on Criticism_, have exercised no slight influence. Boileau
does not merely lay down rules for the language of poetry, but analyses
carefully the various kinds of verse composition, and enunciates the
principles peculiar to each. Of the four books of _L'Art poetique_, the
first and last consist of general precepts, inculcating mainly the great
rule of _bon sens_; the second treats of the pastoral, the elegy, the
ode, the epigram and satire; and the third of tragic and epic poetry.
Though the rules laid down are of value, their tendency is rather to
hamper and render too mechanical the efforts of poetry. Boileau himself,
a great, though by no means infallible critic in verse, cannot be
considered a great poet. He rendered the utmost service in destroying
the exaggerated reputations of the mediocrities of his time, but his
judgment was sometimes at fault. The _Lutrin_, a mock heroic poem, of
which four cantos appeared in 1674, furnished Alexander Pope with a
model for the _Rape of the Lock_, but the English poem is superior in
richness of imagination and subtlety of invention. The fifth and sixth
cantos, afterwards added by Boileau, rather detract from the beauty of
the poem; the last canto in particular is quite unworthy of his genius.
In 1674 appeared also his translation of Longinus _On the Sublime_, to
which were added in 1693 certain critical reflections, chiefly directed
against the theory of the superiority of the moderns over the ancients
as advanced by Charles Perrault.
Boileau was made historiographer to the king in 1677. From this time the
amount of his production diminished. To this period of his life belong
the satire, _Sur les femmes_, the ode, _Sur la prise de Namur_, the
epistles, _A mes vers_ and _Sur l'amour de Dieu_, and the satire _Sur
l'homme_. The satires had raised up a crowd of enemies against Boileau.
The 10th satire, on women, provoked an _Apologie des femmes_ from
Charles Perrault. Antoine Arnauld in the year of his death wrote a
letter in defence of Boileau, but when at the desire of his friends he
submitted his reply to Bossuet, the bishop pronounced all satire to be
incompatible with the spirit of Christianity, and the 10th satire to be
subversive of morality. The friends of Arnauld had declared that it was
inconsistent with the dignity of a churchman to write on any subject so
trivial as poetry. The epistle, _Sur l'amour de Dieu_, was a triumphant
vindication on the part of Boileau of the dignity of his art. It was not
until the 15th of April 1684 that he was admitted to the Academy, and
then only by the king's wish. In 1687 he retired to a country-house he
had bought at Auteuil, which Racine, because of the numerous guests,
calls his _hotellerie d'Auteuil_. In 1705 he sold his house and returned
to Paris, where he lived with his confessor in the cloisters of Notre
Dame. In the 12th satire, _Sur l'equivoque_, he attacked the Jesuits in
verses which Sainte-Beuve called a recapitulation of the _Lettres
provinciales_ of Pascal. This was written about 1705. He then gave his
attention to the arrangement of a complete and definitive edition of his
works. But the Jesuit fathers obtained from Louis XIV. the withdrawal of
the privilege already granted for the publication, and demanded the
suppression of the 12th satire. These annoyances are said to have
hastened his death, which took place on the 13th of March 1711.
Boileau was a man of warm and kindly feelings, honest, outspoken and
benevolent. Many anecdotes are told of his frankness of speech at court,
and of his generous actions. He holds a well-defined place in French
literature, as the first who reduced its versification to rule, and
taught the value of workmanship for its own sake. His influence on
English literature, through Pope and his contemporaries, was not less
strong, though less durable. After much undue depreciation Boileau's
critical work has been rehabilitated by recent writers, perhaps to the
extent of some exaggeration in the other direction. It has been shown
that in spite of undue harshness in individual cases most of his
criticisms have been substantially adopted by his successors.
Numerous editions of Boileau's works were published during his
lifetime. The last of these, _Oeuvres diverses_ (1701), known as the
"favourite" edition of the poet, was reprinted with variants and notes
by Alphonse Pauly (2 vols., 1894). The critical text of his works was
established by Berriat Saint-Prix, _Oeuvres de Boileau_ (4 vols.,
1830-1837), who made use of some 350 editions. This text, edited with
notes by Paul Cheron, with the _Boloeana_ of 1740, and an essay by
Sainte-Beuve, was reprinted by Garnier _freres_ (1860).
See also Sainte-Beuve, _Causeries du lundi_, vol. vi.; F. Brunetiere,
"L'Esthetique de Boileau" (_Revue des Deux Mondes_, June 1889), and an
exhaustive article by the same critic in _La Grande encyclopedie_; G.
Lanson, _Boileau_ (1892), in the series of _Grands ecrivains
francais_.
BOILER, a vessel in which water or other liquid is heated to the boiling
point; specifically, the apparatus by which steam is produced from
water, as one step in the process whereby the potential energy of coal
or other fuel is converted into mechanical work by means of the
steam-engine. Boilers of the latter kind must all possess certain
essential features, whilst of other qualities that are desirable some
may not be altogether compatible with the special conditions under which
the boilers are to be worked. Amongst the essentials are a receptacle
capable of containing the water and the steam produced by its
evaporation, and strong enough continuously to withstand with safety the
highest pressure of steam for which the boiler is intended. Another
essential is a furnace for burning the fuel, and a further one is the
provision of a sufficiency of heating surface for the transmission of
the heat produced by the combustion of the fuel to the water which is
required to be evaporated. Desirable qualities are that the arrangements
of the furnaces should be such that a reasonably perfect combustion of
the fuel should be possible, and that the heating surfaces should be
capable of transmitting a large proportion of the heat produced to the
water so as to obtain a high evaporative efficiency. Further, the design
generally should be compact, not too heavy or costly, and such that the
cleaning necessary to maintain the evaporative efficiency can be easily
effected. It should also be such that the cost of upkeep will be small,
and that only an average amount of skill and attention will be required
under working conditions. It is for providing these qualities in
different degrees according to the special requirements of various
circumstances that the very different designs of the various types of
boilers have been evolved.
_Classes of Boilers._--Boilers generally may be divided into two
distinct classes, one comprising those which are generally called "tank"
boilers, containing relatively large quantities of water, and the other
those which are generally called "water-tube" boilers, in which the
water is mainly contained in numerous comparatively small tubes. There
are, however, some types of boiler which combine to some extent the
properties of both these classes. Each class has its representatives
amongst both land and marine boilers. In "tank" boilers the outer shell
is wholly or partially cylindrical, this form being one in which the
necessary strength can be obtained without the use of a large number of
stays. The boilers are generally internally fired, the furnace plates
being surrounded with water and forming the most efficient portion of
the heating surfaces. On leaving the furnace the products of combustion
are led into a chamber and thence through flues or through numerous
small tubes which serve to transmit some of the heat of combustion to
the water contained in the boiler. In "water-tube" boilers the fire is
usually placed under a collection of tubes containing water and forming
the major portion of the heating surface of the boiler. Both the fire
and the tubes are enclosed in an outer casing of brickwork or other
fire-resisting substance. In some forms of water-tube boiler the fire
is entirely surrounded by water-tubes and the casing is in no part
exposed to the direct action of the fire. In "tank" boilers generally no
difficulty is experienced in keeping all the heating surfaces in close
contact with water, but in "water-tube" boilers special provision has to
be made in the design for maintaining the circulation of water through
the tubes. (For "flash" boilers see MOTOR VEHICLES, and for domestic
hot-water boilers HEATING.)
Lancashire.
_Tank Boilers._--Of large stationary boilers the forms most commonly
used are those known as the "Lancashire" boiler, and its modification
the "Galloway" boiler. These boilers are made from 26 to 30 ft. long,
with diameters from 6-1/2 to 8 ft., and have two cylindrical furnace
flues which in the "Lancashire" boiler extend for its whole length
(see fig. 3). The working pressure is about 60 lb. per sq. in. in the
older boilers, from 100 lb. to 120 lb. per sq. in. in those supplying
steam to compound engines, and from 150 to 170 lb. where triple
expansion engines are used. In some cases they have been constructed
for a pressure of 200 lb. per sq. in. The furnace flues are usually
made in sections from 3 to 3-1/2 ft. long. Each section consists of
one plate bent into a cylindrical form, the longitudinal joint being
welded, and is flanged at both ends, the various pieces being joined
together by an "Adamson" joint (fig. 1.). It will be seen that these
joints do not expose either rivets or double thickness of plate to the
action of the fire; they further serve as stiffening rings to prevent
collapse of the flue. In most of these boilers the heating surface is
increased by fitting in the furnace flues a number of "Galloway"
tubes. These are conical tubes, made with a flange at each end, by
means of which they are connected to the furnace plate. They are so
proportioned that the diameter of the large end of the tube is
slightly greater than that of the flange of the small end; this
enables them to be readily removed and replaced if necessary. These
tubes not only add to the heating surface, but they stiffen the flue,
promote circulation of the water in the boiler, and by mixing up the
flue gases improve the evaporative efficiency.
[Illustration: FIG. 1.--Adamson Joint.]
In the "Galloway" boiler the two furnaces extend only for about 9 or
10 ft. into the boiler, and lead into a large chamber or flue in which
a number of "Galloway" tubes are fitted, and which extends from the
furnace end to the end of the boiler. A cross section of this flue
showing the distribution of the Galloway tubes is shown in fig. 2.
When boilers less than about 6-1/2 ft. in diameter are needed, a
somewhat similar type to the Lancashire boiler is used containing only
one furnace. This is called a "Cornish" boiler.
[Illustration: FIG. 2.--Galloway Boiler: Section beyond the Bridge.]
In all three types of boiler the brickwork is constructed to form one
central flue passing along the bottom of the boiler and two side flues
extending up the side nearly to the water-level. A cross section of
the brickwork is shown in fig. 2. The usual arrangement is for the
flue gases to be divided as they leave the internal flue; one-half
returns along each side flue to the front of the boiler, and the whole
then passes downwards into the central flue, travelling under the
bottom of the boiler until the gases again reach the back end, where
they pass into the chimney. In a few cases the arrangement is
reversed, the gases first passing along the bottom flue and returning
along the side flues. This latter arrangement, whilst promoting a more
rapid circulation of water, has the disadvantage of requiring two
dampers, and it is not suitable for those cases in which heavy
deposits form on the bottoms of the boilers.
Vertical.
Where floor space is limited and also for small installations, other
forms of cylindrical boilers are used, most of them being of the
vertical type. That most commonly used is the simple vertical boiler,
with a plain vertical fire-box, and an internal smoke stack traversing
the steam space. The fire-box is made slightly tapering in diameter,
the space between it and the shell being filled with water. In all but
the small sizes cross tubes are generally fitted. These are made about
9 in. in diameter of 3/8-in. plate flanged at each end to enable them
to be riveted to the fire-box plates. They are usually fitted with a
slight inclination to facilitate water circulation. and a hand-hole
closed by a suitable door is provided in the outer shell opposite to
each tube for cleaning purposes. A boiler of this kind is illustrated
in fig. 4. This form is often used on board ship for auxiliary
purposes. Where more heating surface is required than can be obtained
in the cross-tube boiler other types of vertical boiler are employed.
For instance, in the "Tyne" boiler (fig. 5) the furnace is
hemispherical, and the products of combustion are led into an upper
combustion chamber traversed by four or more inclined water-tubes of
about 9 in. diameter and by several vertical water-tubes of less
diameter. In the "Victoria" boiler made by Messrs Clarke, Chapman &
Co., and illustrated in fig. 6, the furnace is hemispherical; the
furnace gases are led to an internal combustion chamber, and thence
through numerous horizontal smoke-tubes to a smoke-box placed on the
side of the boiler. In the somewhat similar boiler known as the
"Cochran," the combustion chamber is made with a "dry" back. Instead
of a water space at the back of the chamber, doors lined with
firebrick are fitted. These give easy access to the tube ends.
[Illustration: FIG. 3.--Lancashire Boiler.]
[Illustration: FIG. 4.--Simple Vertical Boiler (Messrs Tinker, Ltd.).]
Marine.
The cylindrical multitubular return tube boiler is in almost universal
use in merchant steamers. It is made in various sizes ranging up to 17
ft. in diameter, the usual working pressure being from 160 to 200 lb
per sq. in., although in some few cases pressures of 265 lb. per sq.
in. are in use. These boilers are of two types, double- and
single-ended. In single-ended boilers, which are those most generally
used, the furnaces are fitted at one end only and vary in number from
one in the smallest boiler to four in the largest. Three furnaces are
the most usual practice. Each furnace generally has its own separate
combustion chamber. In four furnace boilers, however, one chamber is
sometimes made common to the two middle furnaces, and sometimes one
chamber is fitted to each pair of side furnaces. In double-ended
boilers furnaces are fitted at each end. In some cases each furnace
has a separate combustion chamber, but more usually one chamber is
made to serve for two furnaces, one at each end of the boiler. The two
types of boilers are shown in figs. 7 and 8, which illustrate boilers
made by Messrs D. Rowan & Co. of Glasgow, and which may be taken as
representing good modern practice. The furnaces used in the smaller
sizes are often of the plain cylindrical type, the thickness of plate
varying from 3/8 in. up to 3/4 in. according to the diameter of the
furnace and the working pressure. Occasionally furnaces with "Adamson"
joints similar to those used in Lancashire boilers are employed, but
for large furnaces and for high pressures corrugated or ribbed
furnaces are usually adopted. Sketches of the sections of these are
shown in fig. 9. The sections of the Morison, Fox and Deighton types
are made from plates originally rolled of a uniform thickness, made
into a cylindrical form with a welded longitudinal joint and then
corrugated, the only difference between them being in the shapes of
the corrugations. In the other three types the plates from which the
furnaces are made are rolled with ribs or thickened portions at
distances of 9 in. These furnaces are stronger to resist collapse than
plain furnaces of the same thickness, and accommodate themselves more
readily to changes of temperature.
[Illustration: FIG. 5.--Vertical Boiler with Water-tubes (the "Tyne,"
by Messrs Clarke, Chapman & Co.).]
There are two distinct types of connexion between the furnaces and the
combustion chambers. In one, shown in fig. 8, the furnace is flanged
at the crown portion for riveting to the tube plate, and the lower
part of the furnace is riveted to the "wrapper" or side plate of the
combustion chamber. In the other type, shown in fig. 7, and known
generally as the "Gourlay back end," the end of the furnace is
contracted into an oval conical form, and is then flanged outwards
round the whole of its circumference. The tube plate is made to extend
to the bottom of the combustion chamber, and the furnace is riveted to
the tube plate. The advantage of the Gourlay back end is that in case
of accident to the furnace it can be removed from the boiler and be
replaced by one of the same design without disturbing the end plates,
which is not possible with the other design. The Gourlay back end,
however, is not so stiff as the other, and more longitudinal stays are
required in the boiler.
[Illustration: FIG. 6.--Vertical Boiler with internal combustion
chamber (the "Victoria," by Messrs Clarke, Chapman & Co.).]
[Illustration: FIG. 7.--Single-ended Marine Boiler.]
The flat sides and backs of the combustion chambers are stayed either
to one another or to the shell of the boiler by numerous screw stays
which are screwed through the two plates they connect, and which are
nearly always fitted with nuts inside the combustion chambers. The
tops of the chambers are usually stayed by strong girders resting upon
the tube plates and chamber back plates. In a few cases, however, they
are stayed by vertical stays attached to T bars riveted to the boiler
shell. A few boilers are made in which the chamber tops are
strengthened by heavy transverse girder plates. The end plates of the
boiler in the steam space and below the combustion chambers are stayed
by longitudinal stays passing through the whole length of the boiler
and secured by double nuts at each end. The tube plates are
strengthened by stay tubes screwed into them.
Where natural or chimney draught is used the tubes are generally made
3 or 3-1/4 in. outside diameter and are rarely more than 7 ft. long,
but where "forced" draught is employed they are usually made 2-1/2 in.
diameter and 8 to 8-1/2 ft. long. A clear space of 1-1/4 in. between
the tubes is almost always arranged for, irrespective of size of
tubes.
[Illustration: FIG. 8.--Double-ended Marine Boiler.]
Stay tubes are screwed at both ends, the threads of the two ends being
continuous so that they can be screwed into both tube plates;
occasionally nuts are fitted to the front ends. The stay tubes are
expanded into the plates and then beaded over.
Locomotive.
The locomotive boiler consists of a cylindrical barrel attached to a
portion containing the fire-box, which is nearly rectangular both in
horizontal and vertical section. The fire-box sides are stayed to the
fire-box shell by numerous stays about 1 in. in diameter, usually
pitched 4 in. apart both vertically and horizontally. The top of the
fire-box in small boilers is stayed by means of girder stays running
longitudinally and supported at the ends upon the tube plate and the
opposite fire-box plate. In some boilers the girders are partly
supported by slings from the crown of the boiler. In larger boilers
the crown of the boiler above the fire-box is made flat and the
fire-box crown is supported by vertical stays connecting it with the
shell crown. Provision is generally made for the expansion of the tube
plate, which is of copper, by allowing the two or three cross rows of
stays nearest the tube plate to have freedom of motion upwards but not
downwards. The ordinary tubes are usually 1-3/4 in. diameter. The
fire-bars are generally, though not always, made to slope downwards
away from the fire door, and just below the lowest tubes a fire-bridge
or baffle is fitted, extending about half-way from the tube plate to
the fire-door side of the fire-box. In some cases water-tubes are
fitted, extending right across the fire-box. In a boiler for the
London & South-Western Railway Co., having a grate area of 31.5 sq.
ft. and a total heating surface of 2727 sq. ft., there are 112
water-tubes each 2-3/4 in. diameter. These are arranged in two
clusters, each containing 56, one set being placed above the
fire-bridge, and the other set nearer the fire-door end of the boiler.
The water-tubes are of seamless steel, and are expanded into the
fire-box side plates. In way of these tubes the outer shell side
plates are supported by stay bars passing right through the
water-tubes. The usual pressure of locomotive boilers is about 175
lb. to 200 lb. per sq. in.
[Illustration: FIG. 9.]
A good example of an express locomotive boiler is shown in fig. 10. In
this case the grate area is 30.9 sq. ft. and the heating surface 2500
sq. ft. The barrel is 5 ft. 6 in. diameter, 16 ft. long between tube
plates. The fire-box crown is stayed by vertical stays extending to
the shell crown, except for the three rows of stays nearest the tube
plates. These are supported by cross girders resting upon brackets
secured to the outer shell.
[Illustration: FIG. 10.--Express Locomotive Boiler, with widened
fire-box (Great Northern Railway, England).]
Babcock and Wilcox stationary.
_Water-Tube Boilers._--The "Babcock & Wilcox" boiler, as fitted for
land purposes, and illustrated in fig. 11, consists of a horizontal
cylinder forming a steam chest, having dished ends and two specially
constructed cross-boxes riveted to the bottom. Under the cylinder is
placed a sloping nest of tubes, under the upper end of which is the
fire. The sides and back of the boiler are enclosed in brickwork up to
the height of the centre of the horizontal cylinder and the front is
fitted with an iron casing lined with brick at the lower part.
Suitable brickwork baffles are arranged between the tubes themselves,
and between the nests of tubes and the cylinder, to ensure a proper
circulation of the products of combustion, which are made to pass
between the tubes three times. The nest of tubes consists of several
separate elements, each formed by a front and back header made of
wrought steel of sinuous form connected by a number of tubes. The
upper ends of the front headers are connected by short tubes to the
front cross-box of the horizontal cylinder, the lower ends being
closed. The upper ends of the back headers are connected by longer
pipes to the back cross-box, and their lower ends by short pipes to a
horizontal mud drum to which a blow-off cock and pipe are attached.
The headers are furnished with holes on two opposite sides; those on
one side form the means of connexion between the headers and tubes,
and the others allow access for fixing the tubes in position and
cleaning. The outer holes are oval, and closed by special fittings
shown in fig. 18, the watertightness of the joints being secured by
the outer cover plates. The holes being oval, the inside fitting can
be placed in position from outside, and it is so made as to cover the
opening and prevent any great outrush of steam or water should the
bolt break. Any desired working pressure can be provided for in these
boilers; in some special cases it rises as high as 500 lb. per sq.
in., but a more usual pressure is 180 lb. Like all water-tube
boilers, they require to be frequently cleaned if impure feed-water is
used, but the straightness of their tubes enables their condition to
be ascertained at any time when the boiler is out of use, and any
accumulation of scale to be removed. The superheaters, which are
frequently fitted, consist of two cross-boxes or headers placed
transversely under the cylindrical drum and connected by numerous
C-shaped tubes. They are situated between the tubes and the
steam-chest, and are exposed to the heat of the furnace gases after
their first passage across the tubes. The steam is taken by an
internal pipe passing through the bottom of the drum into the upper
cross-box, then through the C tubes into the lower box, and thence to
the steam pipe. When steam is being raised, the superheater is flooded
with water, which is drained out through a blow-off pipe before
communication is opened with the steam-pipe. In large boilers of this
type, two steam-chests are placed side by side connected together by
two cross steam pipes and by the mud drum. Each, however, has its own
separate feed supply. The largest boiler made has two steam chests
4-1/2 ft. diameter by 25-1/2 ft. long, a grate surface of 85 sq. ft.,
and a total heating surface of 6182 sq. ft.
Stirling.
Another type of water-tube boiler in use for stationary purposes is
the "Stirling" (fig. 12). This boiler consists of four or five
horizontal drums, of which the three upper form the steam-space, and
the one or two lower contain water. The lower drums, where two are
fitted, are connected to each other at about the middle of their
height by horizontal tubes, and to the upper drums by numerous nearly
vertical tubes which form the major portion of the heating surfaces.
The central upper drum is at a slightly higher level than the others,
and communicates with that nearest the back of the boiler by a set of
curved tubes entirely above the water-level, and with the front drum
by two sets--the upper one being above and the lower below the
water-level. The whole boiler is enclosed in brickwork, into which the
supporting columns and girders are built. Brickwork baffles compel the
furnace gases to take specified courses among the tubes. It will be
seen that the space between the boiler front and the tubes form a
large combustion chamber into which all the furnace gases must pass
before they enter the spaces between the tubes; in this chamber a
baffle-bridge is sometimes built. Another chamber is formed between
the first and second sets of tubes. The feed-water enters the back
upper drum, and must pass down the third set of tubes into the lower
drum before it reaches the other parts of the boiler. Thus the coldest
water is always where the temperature of the furnace gases is lowest;
and as the current through the lower drum is slight, the solid matters
separated from the feed-water while its temperature is being raised
have an opportunity of settling to the bottom of this drum, where the
heating is not great and where therefore their presence will not be
injurious. When superheaters are required, they are made of two drums
connected by numerous small tubes, and are somewhat similar in
construction to the boiler proper. The superheater is placed between
the first and second sets of tubes, where it is exposed to the furnace
gases before too much heat has been taken from them. Arrangements are
provided for flooding the superheater while steam is being raised, and
for draining it before the steam is passed through it.
[Illustration: FIG. 11.--Babcock & Wilcox Water-tube Boiler fitted
with Superheaters.]
Woodeson.
A somewhat similar boiler is made by Messrs. Clarke, Chapman & Co.,
and is known as the "Woodeson" boiler (fig. 13). It consists of three
upper drums placed side by side connected together by numerous short
tubes, some above and some below the water-level, and of three smaller
lower drums also connected by short cross tubes. The upper and lower
drums are connected by numerous nearly vertical straight tubes. The
whole is enclosed in firebrick casing. The design permits of the
insides of all the tubes being readily inspected, and also of any tube
being taken out and renewed without displacing any other part of the
boiler.
[Illustration: FIG. 12.--Stirling Water-tube Boiler.]
Belleville.
The earliest form of water-tube boiler which came into general use in
the British navy is the Belleville. Two views of this boiler are shown
in fig. 14. It is composed of two parts, the boiler proper and the
"economizer." Each of these consists of several sets of elements
placed side by side; those of the boiler proper are situated
immediately over the fire, and those of the economizer in the uptake
above the boiler, the intervening space being designed to act as a
combustion chamber. Each element is constructed of a number of
straight tubes connected at their ends by means of screwed joints to
junction-boxes which are made of malleable cast iron. These are
arranged vertically over one another, and except in the case of the
upper and lower ones at the front of the boiler, each connects the
upper end of one tube with the lower end of the next tube of the
element. The boxes at the back of the boiler are all close-ended, but
those at the front are provided with a small oval hole, opposite to
each tube end, closed by an internal door with bolt and cross-bar; the
purpose of these openings is to permit the inside of the tubes to be
examined and cleaned. The lower front box of each element of the
boiler proper is connected to a horizontal cross-tube of square
section, called a "feed-collector," which extends the whole width of
the boiler. When the boiler is not in use, any element can be readily
disconnected and a spare one inserted. The lower part of the
steam-chest is connected to the feed-collector by vertical pipes at
each end of the boiler, and prolongations of these pipes below the
level of the feed-collector form closed pockets for the collection of
sediment. The tubes are made of seamless steel. They are generally
about 4-1/2 in. in external diameter: the two lower rows are 3/8 in.
thick, the next two rows 5/16 and the remainder about 1/5 in. The
construction of the economizer is similar to that of the boiler
proper, but the tubes are shorter and smaller, being generally about
2-3/4 in. in diameter. The lower boxes of the economizer elements are
connected to a horizontal feed pipe which is kept supplied with water
by a feed-pumping engine, and the upper boxes are connected to another
horizontal pipe from which the heated feed-water is taken into the
steam-chest. Both the boiler proper and the economizer are enclosed in
a casing which is formed of two thicknesses of thin iron separated by
non-conducting material and lined with firebrick at the part between
the fire-bar level and the lower rows of tubes. Along the front of the
boiler, above the level of the firing-doors, there is a small tube
having several nozzles directed across the fire-grate, and supplied
with compressed air at a pressure of about 10 lb. per sq. in. In this
way not only is additional air supplied, but the gases issuing from
the fire are stirred up and mixed, their combustion being thereby
facilitated before they pass into the spaces between the tubes. A
similar air-tube is provided for the space between the boiler proper
and the economizer. Any water suspended in the steam is separated in a
special separator fitted in the main steam-pipe, and the steam is
further dried by passing through a reducing-valve, which ensures a
steady pressure on the engine side of the valve, notwithstanding
fluctuations of pressure in the boiler. The boiler pressure is usually
maintained at about 50 lb. per sq. in. in excess of that at which the
engines are working, the excess forming a reservoir of energy to
provide for irregular firing or feeding.
[Illustration: FIG. 13.--Woodeson Boiler (Messrs Clarke, Chapman &
Co.).]
[Illustration: FIG. 14.--Belleville Boiler.]
Niclausse.
Another type of large-tube boiler which has been used in the British
and in other navies is the "Niclausse," shown in fig. 15. It is also
in use on land in several electric-light installations. It consists of
a horizontal steam-chest under which is placed a number of elements
arranged side by side over the fire, the whole being enclosed in an
iron casing lined with firebrick where it is exposed to the direct
action of the fire. Each element consists of a header of rectangular
cross-section, fitted with two rows of inclined close-ended tubes,
which slope downwards towards the back of the boiler with an
inclination of 6 deg. to the horizontal. The headers are usually of
malleable cast iron with diaphragms cast in them, but sometimes steel
has been employed, the bottoms being closed by a riveted steel plate,
and the diaphragms being made of the same material. The headers are
bolted to socket-pieces which are riveted to the bottom of the
steam-chest, so that any element may be easily removed. The tube-holes
are accurately bored, at an angle to suit the inclination of the
tubes, through both the front and back of the headers and through the
diaphragm, those in the header walls being slightly conical. The tubes
themselves, which are made of seamless steel, are of peculiar
construction. The lower or back ends are reduced in diameter and
screwed and fitted with cap-nuts which entirely close them. The front
ends are thickened by being upset, and the parts where they fit into
the header walls and in the diaphragm are carefully turned to gauge.
The upper and lower parts of the tubes between these fitting portions
are then cut away, the side portions only being retained, and the end
is termed a "lanterne." A small water-circulating tube of thin sheet
steel, fitted inside each generating tube, is open at the lower end,
and at the other is secured to a smaller "lanterne," which, however,
only extends from the front of the header to the diaphragm. This
smaller "lanterne" closes the front end of the generating tube. The
whole arrangement is such that when the tubes are in place only the
small inner circulating tubes communicate with the space between the
front of the header and the diaphragm, while the annular spaces in the
generating tubes around the water-circulating tubes communicate only
with the space between the diaphragm and the back of the header. The
steam formed in the tubes escapes from them into this back space,
through which it rises into the steam-chest, whilst the space in the
front of the header always contains a down-current of water supplying
the inner circulating tubes. The tubes are maintained in position by
cross-bars, each secured by one stud-bolt screwed into the header
front wall, and each serving to fix two tubes. The products of
combustion ascend directly from the fire amongst the tubes, and the
combustion is rendered more complete by the introduction of jets of
high-pressure air immediately over the fire, as in the "Belleville"
boiler.
Durr.
The "Durr" boiler, in use in several vessels in the German navy, and
in a few vessels of the British navy, in some respects resembles the
"Niclausse." The separate headers of the latter, however, are replaced
by one large water-chamber formed of steel plates with welded joints,
and instead of the tubes being secured by "lanternes" to two plates
they are secured to the inner plate only by conical joints, the holes
in the outer plate being closed by small round doors fitted from the
inside. In fixing the tubes each is separately forced into its
position by means of a small portable hydraulic jack. The lower ends
of the caps are closed by cap-nuts made of a special heat-resisting
alloy of copper and manganese. Circulation is provided for by a
diaphragm in the water-chamber and by inner tubes as in the Niclausse
boiler. Baffle plates are fitted amongst the tubes to ensure a
circulation of the furnace gases amongst them. Above the main set of
tubes is a smaller set arranged horizontally, and connected directly
to the steam receiver. These are fitted with internal tubes, and an
internal diaphragm is provided so that steam from the chest circulates
through these tubes on its way to the stop-valves. This supplementary
set of tubes is intended to serve as a superheater, but the amount of
surface is not sufficient to obtain more than a very small amount of
superheat.
Yarrow.
The Yarrow boiler (fig. 16) is largely in use in the British and also
in several other navies. It consists of a large cylindrical steam
chest and two lower water-chambers, connected by numerous straight
tubes. In the boilers for large vessels all the tubes are of 1-3/4 in.
external diameter, but in the large express boilers the two rows
nearest to the fire on each side are of 1-1/4 in. and the remainder of
1 in. diameter. They are arranged with their centres forming
equilateral triangles, and are spaced so that they can be cleaned
externally both from the front of the boiler and also cross-ways in
two directions. In some boilers the lower part of the steam-chest is
connected with the water-chambers by large pipes outside the casings
with the view of improving the circulation.
The largest size of single-ended large tube boiler in use has a steam
drum 4 ft. 2 in. diameter, a grate area of 73.5 sq. ft. and 3750 sq.
ft. of heating surface, but much larger double-ended boilers have been
made, these being fired from both ends.
In most of the boilers made, access to the inside is obtained by
manholes in the steam-chest and water-chamber ends, but in the smaller
sizes fitted in torpedo boats the water-chambers are too small for
this, and they are each arranged in two parts connected by a bolted
joint, which makes all the tube ends accessible.
The Babcock & Wilcox marine boiler (fig. 17) is much used in the
American and British navies, and it has also been used in several
yachts and merchant steamers. It consists of a horizontal cylindrical
steam-chest placed transversely over a group of elements, beneath
which is the fire, the whole being enclosed in an iron casing lined
with firebrick. Each element consists of a front and back header
connected by numerous water-tubes which have a considerable
inclination to facilitate the circulation. The upper ends of the front
headers are situated immediately under the steam-chest and are
connected to it by short nipples; by a similar means they are
connected at the bottom to a pipe of square section which extends
across the width of the boiler. Additional connexions are made by
nearly vertical tubes between this cross-pipe and the bottom of the
steam-chest. The back headers are each connected at their upper ends
by means of two long horizontal tubes with the steam-chest, the bottom
ends of the headers being closed. The headers are made of wrought
steel, and except the outer pairs, which are flat on the outer
portions, they are sinuous on both sides, the sinuosities fitting into
one another. The tubes are of two sizes, the two lower rows and the
return tubes between the back headers and steam-chest being 3-15/16
in. outside diameter, and the remaining tubes 1-13/16 in. The small
tubes are arranged in groups of two or four to nearly all of the
sinuosities of the headers, the purpose of this arrangement being to
give opportunities for the furnace gases to become well mixed
together, and to ensure their contact with the heating surfaces.
Access for securing the tubes in the headers is provided by a hole
formed on the other side of the header opposite each of the tubes,
where they are grouped in fours, and by one larger hole opposite each
group of two tubes. The larger holes are oval, and are closed by
fittings similar to those used in the land boiler (fig. 18). The
smaller holes are conical, with the larger diameter on the inside,
and are closed by special conical fittings: the conical portion and
bolt are one forging, and the nut is close-ended. In case of the
breakage of the bolt, the fitting would be retained in place by the
steam-pressure. A set of firebrick baffles is placed so as to cover
rather more than half of the spaces between the upper of the two
bottom rows of large tubes, and another set of baffles covers about
two-thirds of the spaces between the upper small tubes. Vertical
baffles are also built between the smaller tubes, as shown in the
longitudinal section. These baffles compel the products of combustion
to circulate among the tubes in the direction shown by the arrows.
Experience has shown that this arrangement gives a better evaporative
efficiency than where the furnace gases are allowed to pass unbaffled
straight up between the tubes. The boilers are usually fitted in pairs
placed back to back, and one side of each is always made accessible.
On this side the casing is provided with numerous small doors, through
any of which a steam jet can be inserted for the purpose of sweeping
the tubes.
[Illustration: FIG 15.--Niclausse Boiler--transverse section.]
Express boilers.
A class of water-tube boilers largely in use in torpedo-boat
destroyers and cruisers, where the maximum of power is required in
proportion to the total weight of the installation, is generally known
as express boilers. In these the tubes are made of smaller diameter
than those used in the boilers already described, and the boilers are
designed to admit of a high rate of combustion of fuel obtained by a
high degree of "forced draught." Of these express boilers the Yarrow
is of similar construction to the large tube Yarrow boiler already
described with the exception that the tubes are smaller in diameter
and much more closely arranged.
Normand.
In the Normand boiler (fig. 19) there are three chambers as in the
Yarrow, connected together by a large number of bent tubes which form
the heating surface, and also connected at each end by large outside
circulating tubes. The two outer rows of heating tubes on each side
are arranged to touch one another to nearly their whole length so as
to form a "water-wall" for the protection of the outer casing. They
enter the steam-chest at about the water-level. The two inner rows of
tubes, which are bent to the form shown in the figure, also form a
water-wall for the larger portion of the length of the boiler, and
thus compel the products of combustion to pass in a definite course
amongst all the tubes. In the Blechynden and White-Foster boilers
there are also three chambers connected by bent tubes, the curvature
being so arranged that in the former boiler any of the tubes can be
taken out of the boiler through small doors provided in the upper part
of the steam-chest, and in the White-Foster boiler they can be taken
out through the manhole in the end of the steam-chest.
Reed.
In the Reed boiler the tubes are longer and more curved than in the
Normand boiler, and there are no "water-walls," the products of
combustion passing from the fire-grate amongst all the tubes direct to
the chimney. The special feature of the boiler is that each tube,
instead of being expanded into the tube plate, is fitted at each end
with specially designed screw and nut connexions to enable them to be
quickly taken out and replaced if necessary. At their lower ends the
tubes are reduced in diameter to enable smaller chambers to be used
than would otherwise be necessary. Provision is made for access to the
lower tube ends by means of numerous doors in the water-chambers.
Access to the top ends is obtained in the steam-chest.
Thornycroft.
Messrs John I. Thornycroft & Co. make two forms of express boiler. One
called the Thornycroft boiler consists of three chambers connected by
tubes which are straight for the major portion of their length but
bent at each end to enable them to enter the steam- and water-chambers
normally. The outer rows of tubes form "water-walls" at their lower
parts, but permit the passage of the gases between them at their upper
ends. Similarly the inner rows form "water-walls" at their upper
parts, but are open at the lower ends. The products of combustion are
thus compelled to pass over the whole of the heating surfaces. The
fire-rows of tubes in this boiler are made 1-3/8 in. outside diameter
and the remainder are made 1-3/8 in. diameter. Large outside
circulating pipes are provided at the front end of the boiler.
Thornycroft-Schulz.
In the other type of boiler, known as the Thornycroft-Schulz boiler
(fig. 20), there are four chambers, and the fire-grate is arranged in
two separate portions. The two outermost rows of tubes on each side
are arranged to form water-walls at their lower part, and permit the
gases to pass between them at the upper part. The rows nearest the
fires are arranged similarly to those in the Thornycroft boiler.
Circulation in the outer sets of tubes is arranged for by outer
circulating pipes of large diameter connecting the steam- and
water-chambers. For the middle water-chamber several nearly vertical
down-comers are provided in the centre of the boiler. Boilers of this
type are extensively used in the British and German navies.
_Material of Boilers._--In ordinary land boilers and in marine boilers
of all types the plates and stays are almost invariably made of mild
steel. For the shell plates and for long stays, a quality having a
tensile strength ranging from 28 to 32 tons per sq. in. is usually
employed, and for furnaces and flues, for plates which have to be
flanged, and for short-screwed stays, a somewhat softer steel with a
strength ranging from 26 to 30 tons per sq. in. is used. The tubes of
ordinary land and marine boilers are usually made of lap-welded wrought
iron. In water-tube boilers for naval purposes seamless steel tubes are
invariably used. In locomotive boilers the shells are generally of mild
steel, the fire-box plates of copper (in America of steel), the fire-box
side stays of copper or special bronze, and other stays of steel. The
tubes are usually of brass with a composition either of two parts by
weight of copper to one of zinc or 70% copper, 30% zinc; sometimes,
however, copper tubes and occasionally steel tubes are used. Where water
tubes are used they are made of seamless steel.
_Boiler Accessories._--All boilers must be provided with certain
mountings and accessories. The water-level in them must be kept above
the highest part of the heating surfaces. In some land boilers, and in
some of the water-tube boilers used on shipboard, the feeding is
automatically regulated by mechanism actuated by a float, but in these
cases means of regulating the feed-supply by hand are also provided. In
most boilers hand regulation only is relied upon. The actual level of
water in the boiler is ascertained by a glass water-gauge, which
consists of a glass tube and three cocks, two communicating directly
with the boiler, one above and one below the desired water-level, and
the third acting as a blow-out for cleaning the gauge and for testing
its working. Three small try-cocks are also fitted, one just at, one
above, and one below the proper water-level. The feeding of the boiler
is sometimes performed by a pump driven from the main engine, sometimes
by an independent steam-pump, and sometimes by means of an injector. The
feed-water is admitted by a "check-valve," the lift of which is
regulated by a screw and hand-wheel, and which when the feed-pump is not
working is kept on its seating by the boiler pressure.
[Illustration: FIG. 16.--Yarrow Water-tube Boiler.]
Every boiler is in addition supplied with a steam-gauge to indicate the
steam-pressure, with a stop-valve for regulating the admission of steam
to the steam-pipes, and with one or two safety-valves. These last in
stationary boilers usually consist of valves kept in their seats against
the steam-pressure in the boiler by levers carrying weights, but in
marine and locomotive boilers the valves are kept closed by means of
steel springs. One at least of the safety-valves is fitted with easing
gear by which it can be lifted at any time for blowing off the steam.
Blow-out cocks are fitted for emptying the boiler.
Openings must always be made in boilers for access for cleaning and
examination. When these are large enough to allow a man to enter the
boiler they are termed man-holes. They are usually made oval, as this
shape permits the doors by which they are closed to be placed on the
inside so that the pressure upon them tends to keep them shut. The doors
are held in place by one or two bolts, secured to cross-bars or "dogs"
outside the boiler. It is important in making these doors that they
should fit the holes so accurately that the jointing material cannot be
forced out of its proper position. In the few cases where doors are
fitted outside a boiler, so that the steam-pressure tends to open them,
they are always secured by several bolts so that the breakage of one
bolt will not allow the door to be forced off.
_Water-softening._--Seeing that the impurities contained in the
feed-water are not evaporated in the steam they become concentrated in
the boiler water. Most of them become precipitated in the boiler either
in the form of mud or else as scale which forms on the heating surfaces.
Some of the mud and such of the impurities as remain soluble may be
removed by means of the blow-off cocks, but the scale can only be
removed by periodical cleaning. Incrustations on the heating surface not
only lessen the efficiency of the boiler by obstructing the transmission
of heat through the plates and tubes, but if excessive they become a
source of considerable danger by permitting the plates to become
overheated and thereby weakened. When the feed-water is very impure,
therefore, the boilers used are those which permit of very easy
cleaning, such as the Lancashire, Galloway and Cornish types, to the
exclusion of multitubular or water-tube boilers in which thorough
cleaning is more difficult. In other cases, however, the feed-water is
purified by passing it through some type of "softener" before pumping it
into the boiler. Most of the impurities in ordinary feed-water are
either lime or magnesia salts, which although soluble in cold water are
much less so in hot water. In the "softener" measured quantities of
feed-water and of some chemical reagents are thoroughly mixed and at the
same time the temperature is raised either by exhaust steam or by other
means. Most of the impurity is thus precipitated, and some of the
remainder is converted into more soluble salts which remain in solution
in the boiler until blown out. The water is filtered before being pumped
into the boiler. The quantity and kind of chemical employed is
determined according to the nature and amount of the impurity in the
"hard" feed-water.
_Thermal Storage._--In some cases where the work required is very
intermittent, "thermal storage" is employed. Above the boiler a large
cylindrical storage vessel is placed, having sufficient capacity to
contain enough feed-water to supply the boiler throughout the periods
when the maximum output is required. The upper part of this storage
vessel is always in free communication with the steam space of the
boiler, and from the lower part of it the feed-water may be run into the
boiler when required. The feed-water is delivered into the upper part of
the vessel, and arrangements are made by which before it falls to the
bottom of the chamber it runs over very extended surfaces exposed to the
steam, its temperature being thus raised to that of the steam. At times
when less than the normal supply of steam is required for the engine
more than the average quantity of feed-water is pumped into the chamber,
and the excess accumulates with its temperature raised to the
evaporation point. When an extra supply of steam is required, the
feed-pump is stopped and the boiler is fed with the hot water stored in
the chamber. Besides the "storage" effect, it is found that many of the
impurities of the feed become deposited in the chamber, where they are
comparatively harmless and from which they are readily removable.
[Illustration: Longitudinal section.
Section at AB--Front elevation.