or Pontoon, in war, a kind of flat-bottomed boat, whose carcass of wood is lined within and without with tin; they serve to lay bridges over rivers for the artillery and army to march over. The French pontoons, and those of most other powers, are made of copper on the outside; though these cost more at first, yet they last much longer than those of tin; and when worn out, the copper sells nearly for as much as it cost at first; but when ours are rendered useless, they sell for nothing. Our pontoons are 21 feet long, 5 feet broad broad, and depth within 2 feet, 1.5 inches.

Pontoon-Carriage, is made with two wheels only, and two long side-pieces, whose fore ends are supported by a limber; and serves to carry the pontoon, boards, cross timbers, anchors, and every other thing necessary for making a bridge.

Pontoon-Bridge, is made of pontoons shipped into the water, and placed about five or six feet asunder; each fastened with an anchor, when the river has a strong current; or to a strong rope that goes across the river, running through the rings of the pontoons. Each boat has an anchor, cable, baulks, and chocks. The baulks are about five or six inches square, and 21 feet long. The chocks are boards joined together by wooden bars, about three feet broad, and 12 feet long. The baulks are laid across the pontoons at some distance from one another, and the chocks upon them joined close; which makes a bridge in a very short time, capable of supporting any weight.