PONTOON-BRIDGE consists of pontoons slipped 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 chests. The baulks are about five or six inches square, and twenty-one feet in length. The chests are boards joined together by wooden bars, about three feet in breadth and twelve feet in length. The baulks are laid across the pontoons at some distance from one another, and the chests upon them are joined close; which in a very short time makes a bridge capable of supporting any weight.