University of Cambridge: The research also shows that he went on to apply this knowledge repeatedly to mechanical problems for more than 20 years. by Tom Kirk
'Scribbled notes and sketches on a page in a notebook by Leonardo da Vinci, previously dismissed as irrelevant by an art historian, have been identified as the place where he first recorded his understanding of the laws of friction.
'The research by Professor Ian Hutchings, Professor of Manufacturing Engineering at the University of Cambridge and a Fellow of St John’s College, is the first detailed chronological study of Leonardo’s work on friction, and has also shown how he continued to apply his knowledge of the subject to wider work on machines over the next two decades.'
"Leonardo da Vinci׳s studies of friction" by Ian M. Hutchings here