Having recently visited John Harrison’s grave in London and his artefacts at Greenwich, I enjoyed reading about him in Ian Clayton’s article of April 30.
In 1714 Parliament created The Longitude Board and offered a £20,000 reward (£2.75 million at today’s prices) to anyone solving the problem of establishing the east-west position (longitude) of a ship at sea.
John Harrison of Foulby, already a maker of watches, decided to solve the problem by making a clock that could keep the time of a given place.
Many years of dedicated work followed and in 1735 Harrison built his first sea clock.
But it was not until 1761 that his perfected sea watch met the transatlantic test set by The Board of Longitude.
However, Parliament prevaricated and only in 1773, when Harrison was 80 years old, and with the active support of King George III, that Parliament paid the final £8750 of the £20,000 reward.
John Harrison died on his 83rd birthday and is buried in the small graveyard of St John’s Church, Hampstead, North London.
His tomb is a suitably inscribed, large rectangular box.
The grave is well maintained and its location is signposted from the front of the church.
St John’s Church is to be found just off the main shopping street of Hampstead, and the grave is well worth a visit.
Much of Harrison’s work and technology can be found at The Royal Greenwich Observatory and The National Maritime Museum at Greenwich.