What clockwork machine did Leonardo da Vinci design to move on its own without being pushed?

Leonardo da Vinci designed a self-propelled cart that could move without being pushed by a person or animal. Springs inside the mechanism supplied the stored energy, while programmed cams controlled its motion.

The cart is usually described as an early programmable machine. Its front wheels could be set to follow a predetermined path, making the device an ancestor of theatrical automata and programmable mechanical systems. Leonardo’s surviving sketches do not provide every construction detail, so modern reconstructions have helped test how the mechanism might have worked.

This invention was not a motor vehicle in the modern sense. It had no combustion engine, battery, or steering system for a driver. Instead, it used wound springs, gears, and cams, much like elaborate Renaissance clocks and stage machines.

The cart may have been intended for court entertainment or ceremony. In 2006, engineers and historians built a working reconstruction in Florence, demonstrating that the basic concept could operate. It is often confused with Leonardo’s mechanical lion, another automaton associated with court spectacles.