Leonardo da Vinci designed an odometer to measure distance traveled by counting wheel rotations.
His concept used a cart and a wheel connected to a counting mechanism. As the wheel turned, the mechanism recorded successive intervals of travel, allowing the user to estimate the total distance covered. This is the same fundamental principle used by many mechanical odometers.
Leonardo’s design belonged to a broader Renaissance interest in surveying, mapmaking and military engineering. Accurate distance measurement was important for planning roads, fortifications and canals, even when modern precision instruments were unavailable.
Leonardo did not invent the basic idea of counting wheel rotations from nothing; earlier devices and measuring traditions existed. His importance lies in the detailed mechanical design he recorded and in how clearly it connected movement with numerical measurement.