Leonardo da Vinci designed a catapult to hurl stones using a large elastic arm.
Leonardo studied catapults and other projectile machines while developing military designs for Renaissance patrons. His versions used stored mechanical energy in bent wood, twisted material, or tensioned components, which could be released suddenly to throw a projectile toward a target.
A catapult is a broad category of siege engine. It should not automatically be treated as a trebuchet, which uses a counterweight, or a ballista, which resembles a very large crossbow. Leonardo’s catapult studies belong to a long tradition of improving range, power, stability, and ease of reloading.
Many of Leonardo’s military drawings were proposals rather than documented battlefield equipment. They show his habit of examining existing technologies and redesigning them through geometry, leverage, and careful mechanical observation.