Standing the Test of Time

John Harrison is world famous for winning the Longitude Prize by inventing clocks of unparalleled accuracy. In his later years he left instructions on how to build a clock that would be accurate to one second in every hundred days. At the time this was a ludicrous claim – the best clocks were only capable of a second a week when working at optimum performance. Three hundred years ago, Harrison’s obscure written instructions were dismissed as “the ramblings of superannuated dotage”.

Last month, at the Royal Observatory, Greenwich, London, Harrison’s claims were vindicated when his ‘Clock B’ proved to be accurate to within one second over a 100 day trial and became “the most accurate mechanical clock with a pendulum swinging in free air” – certified by Guiness World Records.

The clock is made to Harrison’s exacting instructions and is known as Martin Burgess Clock B - after its modern-day maker. It has been running for over a year and, when the horologists at Greenwich realised that it was to be a record-breaker, a sealed 100 day trial was instigated.

This achievement reminds me of the successful construction of Babbage’s Difference Engine – the world’s first computer – back in 2002. One wonders if there are any other fantastic inventions still waiting to be built. Maybe it’s a good time to dust off Nikola Tesla’s musings on wireless power. Hmm...?

For more on the fascinating story of John Harrison read: John Harrison – Inventor of the Precision Timekeeper – by Jonathan Betts, Senior Curator of Horology, Royal Observatory, Greenwich.