Leonardo da Vinci designed a tribometer to measure friction between surfaces.
A tribometer is an instrument used to investigate friction, wear, and lubrication. Leonardo’s notebooks include experiments and diagrams examining how surfaces resist motion, and later historians have recognized his work as an early systematic study of tribology. His observations connected friction with factors such as load, contact area, and surface condition.
The term tribology was coined much later, in the 20th century, so Leonardo did not use that modern name. Nevertheless, his experiments anticipated important ideas in friction science. He tried to turn a familiar mechanical problem into something measurable, which was unusual for a period when many machine designs relied heavily on qualitative judgment.
A tribometer is not a barometer, which measures atmospheric pressure, or an odometer, which measures distance traveled. Leonardo’s friction apparatus belongs to the history of mechanical testing rather than meteorology or navigation.