Larcum Kendall

Born at Charlbury in Oxfordshire to a Quaker family, Kendall was apprenticed in 1735 to the London watchmaker John Jefferys and then worked for George Graham as a specialist escapement maker. In 1765 he was one of the experts who witnessed Harrison's explanation of H4, and the Board of Longitude commissioned him to copy it. His copy, K1, was completed in 1769; it went with James Cook on his second and third voyages and performed so well that Cook called it his 'never failing guide'.

Kendall's simplified successors were less successful: K2 (1771), later famous for its voyage on HMS Bounty, and K3 (1774) did not match K1. All three are in the collection of the National Maritime Museum, Greenwich.

K1 cost £450, and when it was presented to the Board of Longitude on 13 January 1770 Kendall received a bonus of £50. Although built like a watch, it is about 13 cm across and weighs 1.45 kg. On Cook's second voyage the astronomer William Wales tested it alongside three timekeepers by John Arnold, which did not stand up to the voyage; Cook reported in 1775 that 'Kendall's watch has exceeded the expectations of its most zealous advocate'.

K1's later career was nearly as remarkable. It stopped off Kamchatka in 1779 on Cook's third voyage and its balance spring broke; repaired by Kendall, it sailed with the First Fleet to Botany Bay in 1787–88, was at sea with Admiral Jervis aboard HMS Victory at the Battle of Cape St Vincent in 1797, and was retired to Greenwich in 1802.

Asked in 1770 to teach other workmen to make further copies, Kendall declined, saying they would still be too expensive for general use, and offered instead simpler watches: K2 (1771) was meant to cost about half as much as K1 and K3 (1774) cost £100, but neither matched its accuracy. K2 was taken by the Bounty mutineers to Pitcairn Island and only reached England again in 1840; K3 sailed with Cook, Vancouver and Flinders.