Leonardo da Vinci designed an odometer to measure the distance traveled by a vehicle.
His design used a wheel whose rotation was connected to a counting mechanism. As the wheel turned, gears transferred motion to a series of boxes or indicators, allowing the operator to calculate how far the vehicle had traveled. The principle is the same basic principle used by later mechanical odometers.
Leonardo’s odometer was intended for surveying and military engineering, where accurate distance estimates helped with mapping, road planning, and the movement of armies. It was not an engine and did not propel the cart; it was a measuring instrument attached to a moving vehicle.
The design is often discussed alongside Leonardo’s self-propelled cart, but the two inventions served different purposes. The cart supplied motion through springs, while the odometer recorded distance. Leonardo’s broader notebooks repeatedly connect mechanics with practical measurement, making this device part of his engineering work rather than merely an artistic experiment.