Harrison's First Marine Timekeeper

Abstract

IN connexion with his efforts to make a time keeper which would keep time accurately at sea, John Harrison made four instruments, one in 1735, a second in 1739, a third a few years later, for which he was awarded the Copley medal of the Royal Society, and a fourth which, after being tested on a voyage to Jamaica and back lasting from November 18, 1761, until March 26, 1762, caused him to be adjudged as having won the £20,000 reward offered through the Act of Parliament of 1714. There was much delay in paying Harrison and it was laid down that all four of his time-keepers were to be handed over to the Royal Observatory. These time-keepers naturally were soon superseded by better instru ments, and they ceased to be used and fell into disrepair. Some twelve years ago, however, Lieut.-Comdr. Rupert T. Gould obtained permission to recondition them and he has now completed his labours by the restarting of Harrison's first marine timekeeper, made in 1735, but not used since 1767. All four of Harrison's instruments are thus again in working order, and according to an article in the Times of February 28, No. 1 will be kept going in an air-tight show-case. Needless to say, this instru ment bears little resemblance to a modern chrono meter. It weighs no less than 70 Ib. Tested aboard H.M.S. Centurion and H.M.S. Orford in 1736, however, it gave satisfactory results, and on the voyage home, when the Orford sighted land the reckoning by the clock showed the position of the ship to be off the Lizard, while the ordinary methods of navigation gave the ship's position as off the Start. The former proved to be the correct position.