What Leonardo da Vinci machine used a spring-powered cart to move without being pushed?

Leonardo da Vinci designed a self-propelled cart powered by coiled springs.

Leonardo’s drawings for the cart date to the late fifteenth century. Two large springs, placed beneath the vehicle, stored mechanical energy. Gears and regulating mechanisms transferred that energy to the wheels, allowing the cart to move forward without an animal pushing or pulling it.

The machine was probably intended for theatrical effects or court festivities rather than transportation. Leonardo worked for the Milanese court, where elaborate mechanical displays could entertain guests and support ceremonial events. The cart’s steering and movement were limited compared with a modern vehicle.

The design is sometimes called a robot car, but that label can mislead readers. It was an automaton-like vehicle, not an autonomous computer-controlled automobile. In 2006, researchers built a working reconstruction based on Leonardo’s drawings. The reconstruction helped confirm that the spring-and-gear arrangement could produce motion.