What Leonardo da Vinci invention was a wooden cart that moved using stored spring energy?

Leonardo da Vinci designed a self-propelled cart powered by stored spring energy.

Leonardo’s drawings for the cart date to the late fifteenth century. The vehicle used coiled springs to store energy, while a system of gears transferred that energy to the wheels. A steering mechanism could be set in advance, allowing the cart to follow a predetermined path rather than being continuously driven by a rider.

The machine was not powered by steam, electricity, or an internal-combustion engine. It is therefore better understood as a spring-powered automaton or mechanical vehicle. The design may have been intended for theatrical use, court festivities, or stage effects, although its exact original purpose is uncertain.

A full-scale reconstruction displayed at the 2006 Florence anniversary celebrations showed that the mechanism could operate when built according to Leonardo’s plans. The cart is sometimes called the first automobile, but that label is anachronistic: it had no engine and could not provide sustained, controllable travel like a modern car.