MORTAR, in the military art, is a short cannon of a large bore, with chambers. It is made of brass or iron, and is used to project hollow shells, filled with powder, called bombs, and sometimes also carcasses. (See ARTILLERY.) The mortars used at sea are fixed in bomb-vessels, which are constructed for their reception; they are made somewhat longer and much heavier than those employed on land. The mortar is the most ancient kind of cannon, and was first made in England in 1543. (See GUNNERY.)