What type of vehicle did Leonardo da Vinci sketch that could move by itself using springs?

Leonardo da Vinci sketched a self-propelled cart that could move using springs.

The machine, usually dated to about 1478–1480, was powered by coiled springs mounted inside its body. Gears transmitted the stored spring energy to the wheels, while a steering mechanism helped set the cart’s path. Because it could move without an animal pulling it, the design is often described as an early robot or an ancestor of the automobile.

Leonardo’s drawings do not give a complete modern construction manual, and the machine’s exact operation has been reconstructed from the surviving plans. In 2006, a team in Florence built a working replica based on those drawings. The replica demonstrated that the concept could function, although its travel distance and control were limited.

The cart may have been intended for theatrical use, perhaps to move across a stage during a court celebration. That possible entertainment purpose is a useful reminder that Leonardo’s mechanical designs served art, spectacle, engineering, and military planning alike.