A Pontoon Brid

- fho nnnexed ouscnpuon ot a pontoo. , ooiwtrueted for the GÓfi1111 rly ivo th6 reader au idea of une''Y i striictures are : these " Itjis cnmposed of forty-two wag., tli spare wheels, a.lrs,'spo]ces, htitfs', etc., 2ÓG harneóles, Ihirtyttix India rubber pontoons (ir floats, wilh all the tunb r, pliinking, cabios, anchor., forge, etc., Kiiffïcient to form a bridge ot 600 ioet in lengtb, and 13i feet in width. It can be tlirown, ruady (or t ho passage of troops, in thirty-seven minutes. If used as ralts, a brigada of tive thoussand inon, with equipaje, artillerv, etc, can be passod over tho Hudion, a-l Sing Siog, or the Mississippi, ia t,on hours."