What machine did Leonardo da Vinci design to make a cart move without horses?

Leonardo da Vinci designed a self-propelled cart that could move without horses.

The cart appears in drawings from around 1478 to 1480 and is often described as an early programmable machine. Springs wound inside the cart supplied power, while gears transferred that power to the wheels. Cams helped determine the cart’s movement, allowing the machine to follow a preset route rather than being steered continuously by a driver.

Leonardo may have intended the device for theatrical performances or court spectacles. It could have carried scenery or appeared to move mysteriously during a celebration. The design is therefore closer to an automated stage machine than to a practical automobile.

Researchers reconstructed the cart in the early 21st century. The replicas showed that the mechanism could work, although the precise original performance and intended use remain subjects of historical discussion. It did not use an engine in the modern sense.