Leonardo da Vinci designed an odometer to measure distance with a rotating wheel and a counting mechanism.
His design used a large wheel that turned as it rolled over the ground. Gears transferred the wheel’s motion to a display or container that recorded the distance traveled. In one version, the mechanism could release a small object at regular intervals, allowing the operator to count the measured units.
Leonardo’s odometer was especially relevant to surveying, mapping, and military engineering. Accurate distance measurements helped engineers plan roads, fortifications, and canals. The device was not an electronic instrument and depended on the wheel’s circumference and the gearing ratio.
The idea is often linked to ancient distance-measuring devices, including Roman examples. Leonardo’s contribution was a detailed Renaissance design rather than the invention of distance measurement itself.