Leonardo da Vinci designed a catapult that used a large spring to hurl heavy stones.
His military notebooks contain studies of throwing machines, including catapults with powerful elastic elements and mechanisms for loading and releasing the projectile. The designs show Leonardo analyzing force, leverage, tension, and the movement of heavy objects rather than merely copying ancient weapons.
A catapult launches a projectile by converting stored mechanical energy into motion. Leonardo’s spring-powered version differs from a trebuchet, which uses a counterweight, and from a ballista, which works more like an oversized crossbow. These distinctions matter because Renaissance drawings often grouped many projectile machines under broad artillery categories.
Leonardo’s catapult was primarily a design study. Surviving drawings do not establish that his particular machine was built and used in a battlefield. Its importance lies in the mechanical reasoning visible in the design.