What Leonardo da Vinci device was designed as a self-propelled cart powered by coiled springs?

Leonardo da Vinci’s self-propelled cart was a spring-powered vehicle designed to move without being pushed by a person or animal.

The cart used two large driving wheels connected to coiled leaf springs. When the springs were wound, their stored energy could turn the wheels. A steering mechanism allowed the cart to follow a predetermined path, making it an early example of programmable mechanical movement rather than a modern automobile.

Leonardo probably designed the machine around 1478–1480. Historians have proposed that it may have been intended for theatrical performances or court celebrations, where a moving object could create a dramatic effect. There is no secure evidence that the original cart survived or that Leonardo built a full working version.

The device is often called Leonardo’s automobile, but that label can mislead. It had no engine, fuel system, or driver’s controls in the modern sense. Its importance is its combination of stored mechanical energy, wheel drive, and preset steering.