What Leonardo da Vinci machine was designed to move on its own using coiled springs?

Leonardo da Vinci’s self-propelled cart was designed to move on its own using coiled springs. Created in a drawing from the late 15th century, it is widely described as an early ancestor of the automobile and a forerunner of programmable machines.

The cart used two symmetrical spring-powered mechanisms to turn its wheels. A system of gears transferred the stored energy, while a programmable device made from wooden blocks controlled the distance and direction of travel. The design could be adjusted before release, somewhat like setting a mechanical sequence.

The cart was probably intended for theatrical or ceremonial use rather than road transport. Some historians connect it with court spectacles in Renaissance Italy, although the original purpose is not certain. Modern reconstructions have shown that the mechanism can work, but Leonardo’s surviving drawing leaves several construction details open to interpretation.