What type of cart did Leonardo da Vinci design for recording distances?

Leonardo da Vinci designed an odometer cart for recording the distance traveled by a moving vehicle.

The cart used a wheel and a counting mechanism. As the wheel turned, linked gears could register rotations and release a measured quantity of material, such as small stones, into a container. Counting the stones then provided an estimate of the distance covered. The design translated wheel motion into a practical measurement.

Leonardo’s version belongs to his studies of surveying, engineering, and mechanical instruments. A large wheel made the measurement more convenient because each revolution represented a substantial, repeatable distance. The exact accuracy would have depended on wheel size, terrain, and the gearing system.

An odometer measures distance, whereas a speedometer measures speed. Leonardo’s cart should also not be confused with his spring-powered vehicle, which was designed as a moving machine rather than a measuring instrument. The odometer concept itself has much older precedents, including ancient Roman distance-measuring devices.