Leonardo da Vinci designed a catapult using a spring-powered launching mechanism to throw stones.
His military notebooks contain studies of machines that stored energy and released it suddenly to propel a projectile. In the spring catapult concept, bent components or coiled springs supplied the force that would drive the throwing arm forward.
Leonardo’s designs were part of his work on siege technology and mechanical advantage. They show his interest in improving the consistency and power of older weapons, but a notebook drawing is not evidence that every design was built or used in war.
A catapult is a broad class of projectile launcher. It is often confused with a trebuchet, which uses a long pivoted arm and a counterweight or human traction. Leonardo also studied crossbows, whose projectiles are launched by a bow rather than a throwing arm.