a machine used by the ancients for shooting darts, and which resembled in some measure our crossbow. The word is Latin, signifying a cross-bow, and is derived from the Greek βαλλειν, to shoot or throw. Vegetius informs us that the ballista discharged darts with such rapidity and violence that nothing could resist their force; and Athenaeus adds, that Agistratus made one of little more than two feet in length, which shot darts 500 paces.