Pónton. n.s. [French.]
Ponton is a floating bridge or invention to pass over water: it is made of two great boats placed at some distance from one another, both planked over, as is the interval between them, with rails on their sides: the whole so strongly built as to carry over horse and cannon. Military Dict.
The black prince passed many a river without the help of pontons. Spectator, № 165.