What self-moving cart did Leonardo da Vinci design using springs and geared wheels?

Leonardo da Vinci designed a self-propelled cart using springs and geared wheels.

The cart appears in drawings from the late fifteenth century. Large coiled springs stored energy, while gears transferred that energy to the wheels. A steering mechanism and a system for setting the route were also part of the design, making the machine more than an ordinary wagon pulled by animals.

The cart was probably intended for theatrical or ceremonial use rather than transportation. It could move without a visible driver, which would have made it useful as a stage effect at court events. Because Leonardo’s surviving drawings do not provide every construction detail, modern reconstructions have interpreted the mechanism in different ways.

The machine is sometimes called an early automobile, but that description can mislead. It had no internal-combustion engine and depended on mechanical springs. It is more accurately described as an early self-propelled vehicle or programmable mechanical cart.