William Harrison

Who was William Harrison?

William Harrison was an English instrument maker, the son of John Harrison, inventor of the marine chronometer.

He was born in Barrow-upon-Humber but moved to London to assist his father in developing the chronometer. In 1761 he sailed to Jamaica on HMS Deptford in charge of his aged father's latest development, the "sea watch", now known as the H4 marine watch, which was to undergo critical performance trials during the transatlantic crossing. Parliament had offered a large prize for a practical working solution to the problem of determining longitude at sea and set up the Board of Longitude to evaluate submissions. In spite of the success of the H4 trials, where the timepiece was shown to be very accurate and reliable and had enabled the longitude to be accurately determined, the Board of Longitude insisted on a second transatlantic crossing to confirm the results. He undertook a second voyage in 1764, sailing to Barbados on HMS Tartar. However, the Board of Longitude were still not convinced that the conditions for the prize had been met.