Videos
This explains the mechanisms and parts to measure the passage of time.
https://www.ebay.com/bhp/skeleton-mechanical-watch
https://www.youtube.com/watch?v=jCBiFShqViw
https://en.wikipedia.org/wiki/Used
https://en.wikipedia.org/wiki/Used_to_Love_You
https://en.wikipedia.org/wiki/Used_good
https://en.wikipedia.org/wiki/Used_car
Mechanical Digital Watch History – Unique Watch Guide
Mechanical Watch Movements – o Frei