What Leonardo da Vinci machine is often described as the earliest known self-propelled cart?

Leonardo da Vinci’s self-propelled cart is often described as the earliest known self-propelled vehicle design.

The cart appears in drawings from the late fifteenth century and was probably intended for theatrical effects or stage presentations. Springs wound inside the machine supplied the stored energy, while a programmable system of pegs and gears controlled its movement.

Unlike an automobile, the cart did not use an engine or a steering wheel. Its motion was limited and mechanically programmed. Modern reconstructions have shown that the design can move when built with appropriate interpretations of Leonardo’s drawings.

The cart is sometimes confused with Leonardo’s mechanical lion or his later humanoid robot. Those projects represent different ideas: the cart is a wheeled automaton, the lion was a ceremonial moving figure, and the robot was a human-shaped mechanical device.