a vessel equipped with two masts, viz. the main-mast and mizen-mast, and usually from 100 to 250 tons burden.—Ketches are principally used as yachts or as bomb vessels; the former of which are employed to convey princes of the blood, ambassadors, or other great personages, from one part to another; and the latter are used to bombard citadels, towns, or other fortresses. The bomb ketches are therefore furnished with all the apparatus necessary for a vigorous bombardment; they are built remarkably strong, as being fitted with a greater number of riders than any other vessel of war; and indeed this reinforcement is absolutely necessary to sustain the violent shock produced by the discharge of their mortars, which would otherwise in a very short time shatter them to pieces.