Leonardo da Vinci designed a catapult to hurl stones with a spring-powered arm.
Leonardo’s military notebooks contain designs for improved catapults with large flexible arms and energy-storage systems. Instead of relying only on a bent wooden arm, some versions used springs or tensioned components to store energy before release. A trigger mechanism could then release the arm and launch a projectile.
Catapults were ancient weapons by Leonardo’s time, so his work represents redesign and refinement rather than invention from nothing. He studied how geometry, leverage and stored energy could increase range and reliability. His broader military portfolio also included bridges, artillery and fortified machines.
A catapult is often confused with a trebuchet. A trebuchet uses a counterweight or pulling force on a pivoted beam, while Leonardo’s spring-powered designs used stored elastic energy. No evidence shows that every catapult in his notebooks was built or field-tested.