Leonardo da Vinci designed a spring-powered catapult to hurl stones during siege warfare.
His catapult concepts used stored mechanical energy. A bent spring or flexible wooden element could be pulled back and released, transferring energy to an arm or projectile. The principle allowed a relatively compact machine to launch a heavy object toward a target.
Leonardo studied and redrew many military machines, often trying to improve their range, power, reliability, or ease of operation. His catapult drawings belong to that wider body of Renaissance weapons engineering.
A catapult is a broad category of projectile-launching machine. A trebuchet uses a counterweight or a pulling force, while a ballista resembles a large crossbow. Leonardo’s spring design is therefore best identified as a catapult rather than by one of those more specific mechanisms.