Leonardo da Vinci designed a spring-powered rapid-firing crossbow.
Among Leonardo’s military studies is a repeating crossbow concept intended to speed the loading and release of bolts. The design used a rack or magazine-like arrangement and a mechanical system that could help bring the bow into firing position. Its purpose was to reduce the delay between shots compared with an ordinary crossbow.
The concept belongs to Leonardo’s broader interest in automating repetitive battlefield actions. He studied how springs, gears, levers, and toothed mechanisms could replace some manual effort. However, surviving drawings do not prove that the complete repeating weapon was built or successfully tested.
The idea should not be confused with a modern firearm or with Leonardo’s multi-barrel organ gun. A crossbow stores energy in a bent bow and launches a bolt, whereas a gun uses expanding gases from an explosive charge. Leonardo’s design is notable for mechanical repetition, not for gunpowder propulsion.