Ships Watch
Information on John Harrison and his links to the area

John Harrison (1693 - 1776)

John Harrison was born March 1693, in Foulby, near Wakefield, but the family moved to Barrow-on-Humber soon after.

His father Henry was an estate carpenter and surveyor and while in Barrow John trained in his father's shop. John also learned about the tuning of bells and sang in the church choir during his time in Barrow.

His interest in music was to be influential in the development of his scientific ideas. He was married in 1718, and his son John was born a few months later. By this time he was specialising in making clocks, helped by his youngest brother, James. Two innovations date from this time. One was the grid-iron pendulum which used linked rods of brass and steel for the pendulum, which have different rates of expansion thus keeping the length of the pendulum and the going rate of the clock even at all temperatures.

Later he was to incorporate this idea into his watches as a bimetallic strip, which is still used in thermostats. The other innovation was the grasshopper escapement.John's first wife, Elizabeth, died in May 1726 and in November he married again. Another Elizabeth. They moved to a house on the Barton Road and had two more children, William, born 1728, and Elizabeth, born 1732. John, with his younger brother James, was now working on a clock that could be used at sea, that could be submitted to the Board of Longitude to claim the prize of £20,000 set up by the Act of 1714 and still unclaimed. In 1736 his first sea-clock (H.1.) was sent for official trials to Lisbon. The results were good enough for further funding. The Harrisons moved to London to be near the other scientific instrument makers and their suppliers, to work on the second machine (H.2.). This was finished in 1737 but did not do well in tests. In 1738, John's eldest son died aged 19. In 1739, James moved back to Barrow-on-Humber and was to become a wealthy clock maker, bell-founder and industrialist. John, his wife and their two remaining children settled in Holborn, where he continued working on a third sea-clock (H.3). It was not ready for official trial at sea, until 1761, but by then Harrison had made a deck watch (H.4.) that had much better performance. This was taken by his son William for the trial. By this time, the Rev. Nevil Maskelyne, who was soon to become Astronomer Royal, was also a candidate for the longitude prize, with the Lunar Distance Method of finding longitude, using new tables by Tobias Mayer. As a result the Board of Longitude put up every obstacle they could think of to prevent a "mechanic" like Harrison claiming the award. Even after a second successful trial watched by Maskelyne in Barbados in 1764, Harrison had to produce detailed drawings, and make two more watches. One of these, H.5 was tested by King George III himself in his Observatory at Kew. Eventually Harrison was paid the money owing to him, not by the Board of Longitude but by a special Act of Parliament.

In 1775, when he was 82, John Harrison wrote an account of his life's work. His book is called ‘A Description Concerning Such Mechanism…’ One year later John Harrison died. He is buried at Hampstead Parish Church.