What was Leonardo da Vinci’s four-wheeled self-propelled machine designed to do?

Leonardo da Vinci’s self-propelled cart was designed to move without a driver.

The machine, drawn around 1478 to 1480, used coiled springs to store energy. When released, the springs turned the cart’s wheels through a system of gears. A steering mechanism could be preset, allowing the vehicle to follow a programmed path rather than being guided continuously by a person.

The cart is often called an early robot or an ancestor of the automobile, but both comparisons need care. It had no engine, and its stored spring power could only provide limited movement. The surviving drawings also leave some construction details uncertain. Modern reconstructions have shown that the basic mechanism can operate. Leonardo may have intended the device for theatrical performances, court celebrations, or other events requiring a moving object that appeared to travel by itself.