The ballista, sometimes known as the ballistae (plural), was a historical missile weapon that fired either bolts or stones at a distant target. It was derived from older Greek weapons, but its mechanics were different, using two levers with torsion springs in place of a tension prod, such as the bow of a contemporary crossbow. The springs were made out of a number of twisted skein loops. Early models used spherical stone projectiles of varying diameters or heavy darts for siege warfare. It evolv ... (Read More)