What mechanical device did Leonardo da Vinci design to move without being pushed?

Leonardo da Vinci designed a self-propelled cart to move without being pushed. His drawings from around 1478 to 1480 show a wheeled mechanism powered by coiled springs rather than by a person or animal.

The springs were stored inside drum-like components and could drive the cart through a system of gears. Steering was possible through a preset mechanism, so the cart could follow a programmed route rather than simply roll freely. This makes the design an important early example of programmable mechanical motion.

The cart may have been intended for theatrical performances or court spectacles, where an unusual moving object could surprise an audience. Leonardo’s notebooks do not provide a complete modern-style operating manual, and scholars have reconstructed its likely mechanism from the surviving drawings.

A reconstruction was displayed in 2006 at the Institute and Museum of the History of Science in Florence, now the Museo Galileo. The cart is sometimes called a robot, but it did not think or act autonomously in the modern artificial-intelligence sense.