770 



THE STANDARD DICTION A II Y OF FACTS 



artillery. A complete suit of armor was an 

 elaborate and costly equipment, consisting of a 

 number of different pieces, each with its distinc- 

 tive name. In modern European armies the 

 metal cuirass is still to some extent in use, the 

 cuirassiers being heavy cavalry; and it is said 

 that this piece of armor proves a useful defense 

 against rifle bullets. During all the time that 

 the use of heavy armor prevailed, the horsemen, 

 who alone were fully armed, formed the principal 

 strength of armies; and infantry were generally 

 regarded as of hardly any account. England 

 was, however, an exception, as the English 

 archers were almost at all times, before the inven- 

 tion of gunpowder, an important and sometimes 

 the chief force in the army. The bow (long- 

 bow) of the English archers was from five to six 

 feet in length, and the arrow discharged from 

 it was itself a yard long. The long-bow con- 

 tinued in general use in England till the end 

 of the reign of Elizabeth, and even as late 

 as 1627 there was a body of English archers 

 in the pay of Richelieu at the siege of La 

 Rochelle. 



Armies of the World. 



Bridge. The earliest bridges were no doubt 

 trunks of trees. The arch seerns to have been 

 unknown amongst most of the nations of an- 

 tiquity. Even the Greeks had not sufficient 

 acquaintance with it to apply it to bridge build- 

 ing. The Romans were the first to employ the 

 principle of the arch in this direction, and after 

 the construction of such a work as the great 

 arched sewer at Rome, the Cloaca Maxima, a 

 bridge over the Tiber would be of comparatively 



easy execution. One of the finest examples of 

 the Roman bridge was the bridge built by Au- 

 gustus over the Nera at Narni, the vestiges >t 

 which still remain. It consisted of four arches, 

 the longest of 142 feet span. The most cele- 

 brated bridges of ancient Rome were not gen- 

 erally, however, distinguished by the extraor- 

 dinary size of their arches, nor by the lightness 

 of their piers, but by their excellence and dura- 

 1 'ility. The span of their arches seldom exceeded 

 seventy or eighty feet, and they were mostly 

 semicircular, or nearly so. The Romans built 

 bridges wherever their conquests extended, and 

 in Britain there are still a number of bridges 

 dating from Roman times. One of the m'ist 

 ancient post- Roman bridges in England is the 

 Gothic triangular bridge at Croyland, in Lin- 

 colnshire, said to have been built in 860, having 

 three archways meeting in a common center at 

 their apex, and three roadways. The long->t 

 old bridge in England was that over the Trent 

 at Burton, in Staffordshire, built in the Twelfth 

 Century, of squared freestone, and recently 

 pulled down. It consisted of thirty-six arches, 

 and was 1,545 feet long. Old London bridirc 

 'was commenced in 1176, and finished in 1209. 

 It had houses on each side like a regular street 

 till 1756-58. In 1831, it was altogether removed, 

 the new bridge, which had been begun in 1824, 

 having then been finished. The art of bridge- 

 building made no progress after the destruction 

 of the Roman Empire till the Eighteenth Cen- 

 tury, when the French architects began to intro- 

 duce improvements, and the constructions of 

 Perronet (Nogent-sur-Seine ; Neuilly; Louis 

 XVI. bridge at Paris) are masterpieces. Within 

 the last half century or so the use of steam and 

 iron, the immense developments of all mechani- 

 cal contrivances, and the great demand for rail- 

 way bridges and viaducts have given a great 

 stimulus to invention in this department. Stone 

 bridges consist of an arch or series of arches, 

 and in building them the properties of the arch, 

 the nature of the materials, and many other mat- 

 ters have to be carefully considered. It has been 

 found that in the construction of an arch the 

 slipping of the stones upon one another is pre- 

 vented by their mutual pressure and the friction 

 of their surfaces; the use of cement is thus 

 subordinate to the principle of construction in 

 contributing to the strength and maintenance of 

 the fabric. The masonry or rock which receives 

 the lateral thrust of an arch is called the abut- 

 ment, the perpendicular supports are the piers. 

 The width of an arch is its span; the greatest span 

 in any stone bridge is about 250 feet. A one- 

 span bridge has, of course, no piers. In con- 

 structing a bridge across a deep stream it is 

 desirable to have the smallest possible number 

 of points of support. Piers in the waterway are 

 not only expensive to form, but obstruct the 

 navigation of the river, and by the very extent 

 of resisting surface they expose the structure to 

 shocks and the wearing action of the water. In 

 building an arch, a timber framework is used 

 called the center, or centering. The centering 

 has to keep the stones or voussoirs in position till 

 they are keyed in, that is, all fixed in their places 

 by the insertion of the keystone. The first iron 

 bridges were erected from about 1777 to 1790. 



