What Leonardo da Vinci invention used a spring-powered cart to move without an animal?

Leonardo da Vinci designed a self-propelled cart powered by coiled springs rather than an animal.

The machine appears in drawings from the late 15th century. Two symmetrical springs stored energy and drove the cart’s wheels through a system of gears. Steering could be set in advance, allowing the vehicle to follow a programmed path. This makes it an early example of a mechanical vehicle with programmable movement.

The cart was probably intended for theatrical or ceremonial use, perhaps to move across a stage and surprise spectators. It was not an automobile in the modern sense, because it had no engine, brakes, or steering system controlled by a driver.

A reconstruction built for a 2006 exhibition showed that the design could move, although some details had to be interpreted from Leonardo’s drawings.