Leonardo da Vinci designed an odometer to measure distance traveled by a wheel.
His road-measuring device used a wheel that turned as the machine moved. A linked counting mechanism recorded the wheel’s revolutions, allowing the operator to calculate the distance covered. Leonardo included the concept among his studies of surveying and engineering instruments.
The principle depends on a simple relationship: a known wheel circumference multiplied by the number of revolutions gives the distance traveled. Accurate results therefore require a wheel of known size and consistent contact with the ground.
Leonardo did not invent the idea of measuring travel mechanically; ancient devices had performed similar work. His design is important because it shows Renaissance attempts to make surveying and road measurement more systematic.