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World's oldest clock? Doubtful

Wells Cathedral in Somerset vies with Salisbury Cathedral in Wiltshire over claims to have the World's oldest working clock. Built sometime between 1386 and 1392 according to surviving records, the Wells clock post-dates the Salisbury one by about five years.

But supporters of Wells argue that the Salisbury clock has no dial or hands and was removed from service for nearly fifty years. Now, try drawing a picture of a clock that does not work and has no dial or hands and you'll begin to realise why they suggest that the Salisbury clock isn't a 'proper' clock at all, so doesn't qualify as the oldest working clock. The Wells clock, on the other hand, has run continuously and has two dials, one outside and another one inside. But it's a dubious argument when you remember that the word 'clock' has the same derivation as the German word 'glocke', which simply means 'bell'.

In medieval times, Church clocks rang out seven or eight times a day to call the parishioners to the next service. No one really needed to know the exact time, which was just as well because these early clocks weren't very accurate anyway.

The dial on the outside at Wells is a fairly conventional 12 hour dial with Roman numerals and two hands. It was probably added after the turret movement was installed but still dates to the 14C or 15C. Periodic restoration over the years makes it difficult to date precisely.

The internal one in the Cathedral's triforium is more complex and altogether more interesting. It has a 24 hour universe dial, with two consecutive sequences of Roman numerals I to XII but the hour hand still points to the top at midday, indicating the position of the sun overhead. It gives a geocentric view of the universe, with the Earth at its centre and the sun and moon rotating around it, which was the theory before Copernicus realised that the sun was at the centre, not the Earth. Here the sun is portrayed on the outer ring as the largest of many stars whilst the moon is on an inner ring with a pointer to indicate its phase in a 30 day life.

The clock strikes every fifteen minutes when jousting knights charge at each other to the sound of Jack Blandifers, who strikes the bell above him with his hammer, and two more below him using his heels.

Ralph Erghum was Bishop of Salisbury until 1388 and oversaw the construction of the Salisbury clock so he might well have engaged the same clock builders to construct the one at Wells after his transfer there. This is borne out by strong design and construction similarities between the two movements and some later improvements to the strike system in the one at Wells.

In common with many old clocks, the original escapement was replaced in the 17C with the new and more accurate pendulum and anchor escapement. The whole movement was subsequently replaced altogether with a new mechanical movement in 1884 but the original was moved to the Science Museum where it still runs.

The replacement movement still drives the two dials in the Cathedral at Wells but sadly, the thrice-weekly ritual of winding it by hand, which took nearly an hour, came to an end in August 2010 on the retirement of the Keeper of the Great Clock of Wells, horologist and jeweller Paul Fisher, whose family had looked after it for nearly a hundred years.

An electric winder is now installed, which is no doubt a relief for Mr Fisher as the three weights weighed around three-quarters of a tonne and the heavy iron crank key required about 800 turns each time!

However, the original movement now in London's Science Museum, is still wound by hand, making it one of the World's oldest working clocks, however you define "clock".

Click here to read more about the next clock in this series of articles, the PRAGUE clock.


  • Wells Cathedral c.1175
  • Wells Cathedral 12 hour clock dial
  • Wells Cathedral 24 hour astronomical dial
  • The Wells Cathedral clock movement
  • Well Catherdral clock movement in detail