Page 5 - —(The "Illustrated War News.") 1.—Single Arch Bridge.—A—Board to which slabs of gun-cotton are fixed and is suspended under the 3.— with Steel Girders on Piers.—E—Pier. F.—Slabs of gun-cotton. arch. B—Fuze. C—Detonator. G.—Board. HOW IT WORKS: BRIDGE-DESTRUCTION—METHODS USED BY MILITARY ENGINEERS IN THE CASE OF ARCHED BRIDGES AND GIRDER BRIDGES.