Harrison, John 1693 - 1776
1693-1776, horologist and clock-maker, English
1713 - earliest extant clock.
1726 - first heard of the
1714 Longitude Act.
1735 - completed construction of his 'sea clock', H1.
1736 - sent on a voyage with H1 to determine the longitude of Lisbon.
1739 - after being awarded £500 by the Board of Longitude, completed construction of H2.
1749 - awarded the Copley gold medal by the Royal Society for his experimental work.
1759 - completed H3.
1760 - eventually produced his fourth timekeeper, the H4, the size of a large pocket watch.
1761 - H4 was sent on a trial to Jamaica.