The Clock That Changed The World

The incredible story of a wooden clock from Leeds and its part in a historical scandal involving one of Britain’s worst marine disasters and eventually the King himself. Part of the BBC’s ‘A History Of The World In 100 Objects’ project.

The object is ‘Precision Pendulum No 2’, by John and James Harrison. It is at first sight a ‘grandfather’ clock. Experts call it a long case clock, but it is much more special than than. Made in 1727, at the time it was probably the most accurate clock in the world. John Harrison, a joiner and clockmaker living in Barrow-on-Humber in North Lincolnshire, made it as an experimental clock to help him solve the ‘longitude’ problem. Essentially, ships could not find their position at sea. This turned into a huge deal in the 18th Century following a major accident when a fleet, commanded by the splendidly named Sir Cloudesely Shovell, ran aground in the Scilly Isles, having mistaken their position. 2000 men died. Harrison eventually solved the problem by sending precision clocks to sea. But it took him 50 years.

In this film, Adam Hart-Davis is in Leeds Museums as Precision Pendulum No 2 is taken apart. Amazingly, the movement is wood - yet it was better than the best brass clocks of the time. In an attempt to understand why John Harrison chose this material, Adam makes his own wooden clock (see above). He also joins the crew of the Humber Lifeboat at Spurn Point, who attempt to use 18th century navigation methods. Finally, Adam shows how Harrison’s idea of using precision clocks to find out where you are has an ultra-modern implementation: satellite navigation.

There is a nice article about the clock and John Harrison written by Sheena Hastings in the Yorkshire Post. And the BBC project is at

Executive Producer: Paul Bader

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