John Harrison

John Harrison
Thomas King's 1767 portrait of John Harrison, located at the Science and Society Picture Library, London
Born3 April [O.S. 24 March] 1693
Died24 March 1776(1776-03-24) (aged 82)
London, England
NationalityEnglish
Known forBimetallic strip
Gridiron pendulum
Grasshopper escapement
Longitude by chronometer
Marine chronometer
AwardsCopley Medal (1749)
Longitude rewards (1737 & 1773)
Scientific career
FieldsHorology & 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 how to calculate 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 never received the full reward due to political rivalries. He 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. Towards the end of his life, he received recognition and a reward from Parliament. He came 39th in the BBC's 2002 public poll of the 100 Greatest Britons.[2]

  1. ^ William E. Carter. "The British Longitude Act Reconsidered". American Scientist. Archived from the original on 20 February 2012. Retrieved 19 April 2015.
  2. ^ "100 great British heroes". BBC. 21 August 2002. Retrieved 10 February 2012.