John Harrison

John Harrison
Thomas King's 1767 portrait of John Harrison, located at the Science and Society Picture Library, London
Born	3 April [O.S. 24 March] 1693 Foulby, Wakefield, West Riding of Yorkshire, England
Died	24 March 1776(1776-03-24) (aged 82) London, England
Nationality	English
Known for	Bimetallic strip Gridiron pendulum Grasshopper escapement Longitude by chronometer Marine chronometer
Awards	Copley Medal (1749) Longitude rewards (1737 & 1773)
Scientific career
Fields	Horology & Carpentry

John Harrison (3 April [O.S. 24 March] 1693 – 24 March 1776) was an English carpenter and clockmaker who invented the marine chronometer, a long-sought-after device for solving the problem of calculating longitude while at sea.

Harrison's solution revolutionized navigation and greatly increased the safety of long-distance sea travel. The problem he solved had been considered so important following the Scilly naval disaster of 1707 that the British Parliament was offering financial rewards of up to £20,000 (equivalent to £3.97 million in 2024) under the 1714 Longitude Act,^[1] though Harrison was never fully able to receive these rewards due to political rivalries.

Harrison presented his first design in 1730, and worked over many years on improved designs, making several advances in time-keeping technology, finally turning to what were called sea watches. Harrison gained support from the Longitude Board in building and testing his designs. Toward the end of his life, he received recognition and a reward from Parliament. Harrison came 39th in the BBC's 2002 public poll of the 100 Greatest Britons.^[2]