Wells Cathedral clock, c.1392

The Wells Cathedral Clock was built around 1392 and has been in almost continuous use ever since. It is the second-oldest surviving clock in England (the oldest is at Salisbury Cathedral).

In the 17th century the original mechanism was modified, with the addition of a pendulum and anchor to improve timekeeping. The clock has three trains of wheels - one to keep the clock faces going, one for the strike on the hour, and one for the chimes every quarter hour.

It was completely replaced in 1837 and this original mechanism found its way to the Patent Museum in London in 1871, where new bells were added. In 1884 it became part of the collections of the Science Museum.