Leonardo da Vinci’s self-propelled cart used coiled springs to move without a visible animal or person pushing it.
Leonardo sketched the cart around 1478–1480. Two large springs, mounted inside drum-like housings, stored energy when wound. As they unwound, gears transferred the energy to the wheels, making the cart move forward.
The cart was probably conceived as a theatrical device for court entertainments rather than as a practical road vehicle. A steering mechanism could make it follow a preset path, and reconstructions have shown that the design is mechanically workable. Because the springs provide only limited energy, the cart was not an automobile in the modern sense.
The invention is sometimes called Leonardo’s automobile, but “self-propelled cart” is more precise. It had no engine, fuel tank, or modern transmission. Its importance lies in combining stored mechanical energy, gearing, and programmed movement in a compact machine centuries before motor vehicles became practical.