Larcum Kendall

Plaque

Larcum Kendall (born September 21, 1719 in Charlbury , Oxfordshire , † November 22, 1790 in London ) was a British watchmaker . He is famous for his chronometers. The K1, K2 and K3 timepieces are now housed in The Old Royal Observatory , part of the National Maritime Museum , Greenwich.

K1

The Board of Longitude , the commission for the development of a method for the exact determination of the geographical longitude , commissioned Kendall to recreate John Harrison's ingenious fourth model of a clock useful for navigation at sea and to develop it as possible. The original would have had an astronomical price, around 30% of the value of a ship.

The first model ( time piece or time keeper ) completed by Kendall under this contract in 1769 was an exact copy of the Harrison Model 4 (H4), costing £ 500 and is now known as the K1. James Cook tested the watch on his second voyage to the South Seas and, after initial skepticism, was full of praise: "Kendall's pocket watch exceeded all expectations," he reported to the Admiralty in 1775. Three other clocks, designed by John Arnold, had not withstood the rigors of the same journey. "Pocket watch" is misleading by today's standards: the clock was 13 cm in diameter and weighed 1.45 kg. K1 accompanied British ships to Australia for more than thirty years .

K2

Kendall assured that he would be able to build a similar clock for £ 200 through simplifications, received the order and presented the K2 in 1771. First it was given to John Phipps in 1773 for his expedition to search for a Northwest Passage, then it was used in North America. It was far less accurate than the original. In 1787 William Bligh noted a course in the logbook of the Bounty , a daily inaccuracy that fluctuated irregularly between 1.1 and three seconds.

The watch became famous because of the mutiny on the Bounty . She stayed on board. Christian was able to find out from the clock that Pitcairn was marked incorrectly on the nautical charts and that the mutineers were safe.

Decades after the mutiny, she came back to England : In Pitcairn , Captain Matthew Folger of the American whaler Topaz bought her from John Adams for a bagatelle, but he only took her as far as the Spanish Juan Fernández Islands , whose governor imprisoned him for no reason and the Clock kept. It was last bought by a British captain for £ 52 and 10 shillings from the estate of a Chilean muleteer, who gave it to the Crown in 1843 as a gift.

K3

Kendall's third and last attempt at his own construction, K3, completed in 1774 for £ 100, did not have the required accuracy, as Cook found out, who took it with him on his last trip in addition to K1. Nevertheless, it was still used on Matthew Flinder's 1801 trip to Australia.

Kendall was, as the K1 testifies, a first-rate craftsman but not a good designer. Better developments came from John Arnold and Thomas Earnshaw . John Arnold's construction was so precise that he coined the word chronometer for it in 1780 . However, Arnold's instruments lacked robustness.

It was not until Thomas Earnshaw's models that became established around the world a little later. Arnold and Earnshaw had gone their own way in the design, and, unlike Kendall, both achieved the required accuracy. It was not until the price of around £ 80, at which Earnshaw's devices could be manufactured, although still too expensive for normal merchant shipping, that they became possible.

More chronometers

After the K3, Kendall built chronometers based on Arnold's model.

Web links

• K1 National Maritime Museum (English)
• K2 National Maritime Museum (English)
• K3 National Maritime Museum (English)

Individual evidence

1. ↑ Jonathan Betts: Kendall, Larcum in Dictionary of National Biography Oxford (English)
2. ↑ http://www.dailymail.co.uk/news/article-2368234/Why-captain-Bounty-desperate-save-ships-chronometer-Timepiece-held-key-infamous-mutiny-British-naval-history.html
3. ↑ http://www.winthrop.dk/chrono.html