BRIDGE, 



planks. Mi)dem aniiie« gtnfraUy carry with them a num- 

 ber of thcfe copper boats, or pontoons, that they may 

 always be in rcadinefs for tlirowing over bridges. Several 

 of thefe being joined fide by fide, till they reach acrofi the 

 river, and planks laid over them, make all plain for the 

 troops to march upon. 



The mod remote ages of antiquity foniifh us with many 

 remarkablf indanccs of bridges of this kind. One ot the 

 earlieft upon record, is that laid by Dnrlns Hyftafpts over 

 the Ifter, or Danube, in his Scythian expedition, about the 

 year before Chritl -^oS. Herodotus, 1. iv. c. yS. Darius alfo 

 crolTcd the Thracian Bofphorus with ^00,030 men by means' 

 of a bridge of boats, the ftrait being five ftadia, or ico8 yards 

 in breadth. That of Xcrxts, in the year 4S0 before Chrift, 

 feven Greek fladia, or, as fome eftimate them, nearly a mile in 

 length, acrofs the HcUefpont, is ftill more remarkable. Tlie 

 boat-bridges of Xerxes began at Abydos, and terminated a 

 little below Seftus. This paffage, which is the narrowed part 

 of the llrait, is only about .^y^i toifes. or 800 yards wide. 

 But, as the length of the bridges is faid to have been feven 

 nadia, M. D'Anvillc (M. de I'Acad. des Bell. Lettr. t. 28. 

 p. 334.) has from thence inferred, tliat thefe ftadia were 

 o::ly 51 toifes, or loS yards, each. The firft bridge of 

 Xerxes having been carried away by the force of a tempeft, 

 he fubftituted two others, that towards the Pontus Euxi- 

 nus, confifting of 360 vclTcIs of the largeft dimenfions iifed 

 in the ancient navies ; tlie other of 340. Thefe were flcadily 

 moored by means of large anchors. Six immenfe cables, 

 faftened to large piies driven into the oppollte (hores, ex- 

 tended the whole length of the bridges. Acrofs thefe were 

 laid trunks of trees, ard upon them a flooring, which was 

 covered with eaith for the paflage of the army. Tlie whole 

 was fecured by a railing on cich fide. This contrivance is the 

 model of mod of the bri'lgcs of boats which have fuice 

 been condru£led, with tiiis difference, that the vcdels of 

 Xcrxts were arranged ftem and ftern upon the water, a plan 

 exafily contrary totheprefent method. Tiiat thePcrfianswere 

 in tl e habit of conftrudling bridges of tl;is kind, appears 

 from thefe examples, and from another recorded by Xeno- 

 phon, who mentions that of Sitacc over the Tigris, com- 

 pofed of 27 boats. The Greeks and Romans were very 

 expert in this part of the military fcience. Several bridges 

 of boats are mentioned by Appian, in his account of the 

 fecial war. That of C^efar over the Rhine is farriliar to the 

 readers of ancient hiftory ; and in all his campaigns, ve 

 obferve particular attention on the part of th.at celebrated 

 commander with regard to the paftage of rivers, or preferv- 

 iiig comnvjnications by means of bridges. In the conteft 

 between the armies of Otho and Vitellius about Cremona, 

 a bridge of this kind is noticed by Tacitus. That of Tra- 

 jan over the Danube has been already mentioned. Where 

 boats were wanting, the ingenuity and cruelty of the an- 

 cients found other expedients for overcomir^g the ohftacies 

 prefented by the rivers to their progrefs. Hamilcar Barcas, 

 in his war againd the mercenaries, croffcd the Macar by 

 means of the following ftratagem. He obferved that when 

 the weft-north-wcd wind prevailed, the fand it agitated almod 

 choaked up the mouth of the river, and formed a kind of 

 natural bridge for the palfage of his troops. He availed 

 himfeif of this difcovery to pafs the Macar in the night, 

 and obtain by furprife an c ify viftory. Sapor the Perfian, 

 by a refincmmt in cruelty, made ufe of the bodies of his 

 prifoners to facilitate the patfage of his army. ( Vid. Herod, 

 hb. iv. cap. 97, 101. — Ibid. lib. vii. cap. 3J — 36. — Xeno- 

 phnn Anab. lib. ii — Appian, de Bel. Civ.— Cifar de Bel. 



Gall. lib. iv. — Tacitus, hid. lib. ii.— Dion Caffius, hid 



Polybius, lib. i.~Trebell. Poll, in Valerian.) 



Of late -years the laying of bridges acrofs rivers has been 

 greatly improved and facilitated. In the campaigns of 1 799 

 and 1800 in particular, this branch of the military fcience 

 attained that pinnacle of excellence which it will be difficult 

 to furpafs. few objeils prefent more varied details than 

 the crofling a river by open force, and in prefence of an 

 enemy. In operations of this kind, localities and other phy- 

 fical circumftances differ fo infinitely, and give rife to fuch 

 numerous combinations of advantages or difadvantages, that 

 it is impofiible to lay down any given precepts which may 

 be applicable in all cafes. What may be very proper and 

 feafible upon one river, or at a certain feafon of the year, 

 may be inipraiSicable tlfewhere, or in any other period. 

 Sometimes the necefTaries for the expedition mud be tranf. 

 ported by water ; at others, by land. Rivers which have 

 marlhy banks, a fmooth bed, an even current, and a muddy 

 bottom, require totally different precautions from tliofe with 

 a rapid and formidable cunent, which are overhung with 

 thick woods, or have a rocky bottom. The bed ccrr.men- 

 tary upon thefe feveial cafes, will be a detailed account of 

 the operations adopted in them. 



The paffages of the Rhine by the French troops at Ur- 

 dingen, Ncuwicd, Kebl, and Dierditira ; at Reichlingen, 

 Atzmoor, and Lucidieg in Swiflerland ; thofe of the Lim- 

 mat, the Danube, the Lech, the Inn, and finally of the 

 Mincio, will evince the progrefs lately made in the conllruc- 

 tion of bridges of pontoons. Two of thefe have been 

 treated with great precifion by an engineer in the French 

 fervice, whofe work well deferves the attention of military 

 men in general. (Dedon, relation des paflages, de la Lim- 

 mat et du Rhin. Par. 1801, 8vq.) 



Under this article of briJgcs we may alfo mention portable 

 bridges, eafily taken afunder, and put together again. M. 

 Couplet mentions one of this kind, 200 feet long, and 

 which 40 men may cari-y. See Du Hamel. Hid. Roy. 

 Acad. Scienc. 1. iii. ^ y. c. 4. 



Pendant, or hanging Irhlgej, called alfo phUofophical bridges, 

 are thofe which are not fupported by pods or pillars, but 

 hang at large in the air, being fudained only at the two 

 ends or hutments. Of fuch bridges, confiding of a fingle 

 large arch, inftances have been already mentioned. Bridges 

 of this kind are ufed by the Spaniards for pafTmg the tor- 

 rents in Peru, over which it would be difficult to throw more 

 folid druftures either of done or timber. Some of thefe 

 hanging bridges are formed fo drongand broad, that loaded 

 mules pafs along them. Ulloa, tom. i. 3 58. Dr. Wallis 

 gives the dcfign of a timber-bridge, 70 feet long, without 

 any pillars, which may be ufeful in places where pillars can- 

 not be convenieatly crefted. Phi!. Tranf. N° i6j, p. 714. 

 Dr. Plott informs us, that there was formerly a large bridge 

 over the cadle-ditch at Tutbury in StafFordfliire, made of 

 pieces of timber, none much above a yard long, and yet not 

 fupported underneath, either with pillars or arch-work, or 

 any other fort of prop whatever. 



It has been already mentioned, that the ancient Romans 

 paid particidar attention to the condrutlion and reparation 

 of bridges ; and that in the middle ages the building of 

 bridges was reckoned among the afts of religion. By our 

 ancient laws, pintium reparatlo, or the reparation of bridges, 

 was part of the trinoda necejfitas, to which every man's eftate 

 was fubjed. However, by the great charter, 9 Hen. III. 

 c. 15. no town nor freeman fhall be diilrained to make 

 bridges nor banks, but fuch as of old time, and of right, have 

 been accuftomed. And none can be compelled to make 

 new bridges, where none were ever before, otherwife than by 

 ad of parliament. 2 Lid. 701. By the common law, fome 

 ptrfous are bound to repair bridges by reafon of llie tenure 



of 



