John Harrison

John Harrison (1693 to 1776) was an English joiner and clockmaker who invented the marine chronometer, a long-sought device for solving the problem of how to calculate longitude while at sea. His solution revolutionized navigation and greatly increased the safety of long-distance sea travel. The problem had been considered so important after the Scilly naval disaster of 1707 that the British Parliament offered financial rewards of up to 20,000 pounds under the 1714 Longitude Act, though Harrison never received the full reward because of political rivalries. He presented his first design in 1730 and worked over many years on improved designs, making several advances in time-keeping technology before turning to what were called sea watches. He gained support from the Longitude Board in building and testing his designs, and near the end of his life he received recognition and a reward from Parliament.