Pont levis, Fr. See [Drawbridge].
Pont tournant, Fr. a moveable bridge. It is of the nature of a drawbridge, with this difference, that it turns upon a pivot, and goes entirely round.
Pont de bois, Fr. a wooden bridge.
Pont de corde, Fr. a bridge of ropes.
Pont de jonc, Fr. a bridge of rushes.
Pont suspendu, Fr. a hanging bridge.
Pont de sortie, Fr. a sally bridge.
Pont dormant, Fr. a wooden bridge, which is generally laid upon the fosse of a fortified town, for the purpose of maintaining a constant communication between the main body of the place and the outworks and country round. These bridges are not thrown entirely across the fosses, but terminate within twelve or fifteen feet of the revetement; the space from thence is supplied by drawbridges. When the ponts dormans are very long, a swing bridge is constructed in the centre of it. When the ditches are wet, and so constantly supplied with water that the depth of it is generally the same, bridges of boats may be used instead of ponts dormans. And in cases of attack, floating bridges may be substituted in lieu of both.
PONTON, or PONTOON, 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 they 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 that of tin are rendered useless, they sell for nothing. The British pontoons are 21 feet long, 5 feet broad, and depth within 2 feet 3 inches.
PONTOONS. Length at top, 21 feet 6 inches. Length at bottom, 17 feet 2 inches. Width, 4 feet 9 inches, or 5 feet. Depth, 2 feet 3 inches.