Leonardo da Vinci designed an odometer to measure how far a cart traveled.
His device used a wheel that turned as the cart moved. A system of gears transferred the wheel's rotation to a display, allowing the operator to count traveled distance. The design was intended for surveying and mapping rather than for modern automobile use.
Leonardo's odometer is often associated with his broader interest in military engineering, architecture, and accurate measurement. It was not an electronic instrument and did not resemble the digital displays found in modern vehicles. The related term “odometer” comes from Greek roots meaning road and measure.
Leonardo also studied devices for measuring wind, water, time, and mechanical motion. His sketches show that he treated measurement as essential to building reliable machines, bridges, canals, and fortifications.