What self-propelled machine did Leonardo da Vinci design centuries before the automobile?

Leonardo da Vinci designed a self-propelled cart, a spring-powered machine often described as an early ancestor of the automobile. It was intended to move without being pushed or pulled by an animal.

The cart used tightly wound leaf springs to store energy. A system of gears controlled the release of that energy, while steering could be set in advance. The mechanism resembles a theatrical automaton or ceremonial vehicle more than a practical road car.

Leonardo’s drawing was discovered in the Codex Atlanticus, and modern reconstructions have shown that the mechanism can work. The cart did not use an internal-combustion engine, battery, or steam engine. Calling it the first automobile is therefore a useful popular comparison, but it should not be confused with a modern motor vehicle.