“the rubbings of weights are of so many different resistances as are there are differences in the bodies that can rub together. And if the surfaces of the bodies that rub together are dense and of planar resistance, then a greater contact will make resistance equal to that of the lesser. Circular rubbing is equal to straight rubbing.”
Leonardo is one of the first scholars to study friction ("confregazione") systematically, guessing its relevance in the functioning of machines. He makes a distinction between sliding friction and rolling friction. He studies the friction of hinges and examines their behaviour in relation to the nature and shape of materials in contact or by introducing lubricants and rolls. This display shows reproductions of different models of antifriction rolls, each of them marked with a letter.
The model is based on the drawings:
- Codex Arundel f. 41 r. (1500 ca.)
London, British Library
- Manuscript L f. 11 v. (1500 ca.)
Paris, Institut de France