What Leonardo da Vinci device measured friction between surfaces?

Leonardo da Vinci designed a tribometer to measure friction between surfaces.

The device used a block or object pulled across a surface while a weight or force system provided a measurable load. By comparing the force needed to move the object, investigators could study resistance between materials.

Leonardo’s friction studies are important because they treated friction as something that could be measured systematically rather than described only by observation. His notebooks contain experiments involving different surfaces, loads and conditions.

The term tribometer is broader than Leonardo’s particular apparatus: modern tribometers test friction, wear and lubrication using many different configurations. The instrument should also not be confused with a dynamometer, which measures force or torque more generally. Leonardo’s contribution lies in the early experimental study of tribology.