What transport device did Leonardo da Vinci design that moved using springs and gears?

Leonardo da Vinci designed a self-propelled cart that moved using wound springs and gears.

The machine is described in drawings from the late fifteenth century. Two large leaf springs stored energy, while a gear system transferred that energy to the cart’s wheels. A steering mechanism also allowed the vehicle to follow a predetermined path, making it more than a simple wheeled platform.

The cart is often called an early ancestor of the automobile, but it had no engine in the modern sense. Its stored mechanical energy came from springs rather than gasoline, electricity, or steam. Historians also debate some construction details because Leonardo’s surviving drawings do not show every part clearly. Modern replicas have demonstrated that the basic mechanism can work.