Leonardo da Vinci designed an odometer to measure the distance traveled by a wheeled cart.
His cart-based device used wheel rotation to drive a counting mechanism. As the cart moved, each turn of the wheel advanced gears or a series of compartments, allowing the operator to estimate the distance covered from the number of rotations.
Leonardo’s odometer was intended for surveying and mapping. A known wheel circumference provides a direct relationship between revolutions and distance, making the device useful for measuring roads or plotting routes. The design also illustrates Leonardo’s interest in converting continuous motion into readable numerical information.
An odometer measures distance, not speed. A speedometer measures how quickly something is moving, while a compass indicates direction. Leonardo’s design should also be distinguished from his self-propelled cart: that machine supplied motion, whereas the odometer recorded travel.