Leonardo da Vinci’s spring-powered siege machine was a catapult.
Leonardo designed catapults that used stored elastic energy to hurl projectiles. Some of his concepts employed large bent beams or springs, ropes, and release mechanisms to amplify the force produced by a relatively small movement. The goal was to improve the range, power, or controllability of an ancient siege technology.
Leonardo’s catapult designs were largely proposals in his engineering notebooks rather than proven battlefield weapons. A catapult is a broad category of projectile-launching machine. A trebuchet uses a counterweight or traction system, while a ballista resembles a giant crossbow and uses tension in arms or cords. Leonardo studied all kinds of military machinery, so identifying the operating principle is important when distinguishing his catapult concepts from his other siege designs.