Clocks are so much more interesting than I thought.

3-Second Blueprint (English)

1. The Cumbria Clock Company restores and maintains over 1,400 mechanical public and church clocks across Britain, including Big Ben.
2. Turret movements gear down to one revolution per hour, driving external tower hands via bevel gears while a handset dial shows time inside.
3. Hourly bell chimes use a notched count wheel whose progressively longer outer segments hold a cam lever up for one to twelve strikes.