Width: 160.000 mm
Height: 84.000 mm (box)
M&ME CAI 2067
Prehistory and Europe
Marine chronometer no. 12 by John Arnold
London, England, about AD 1778-1779
John Harrison's timekeeper, now known as H4, was tested at sea in 1761-62 and provided the solution to finding longitude at sea. This opened the way for others to perfect and simplify the marine timekeeper. One leading clockmaker who devoted considerable effort to this task was John Arnold (1735/6-99). It was perhaps John Arnold and his rival Thomas Earnshaw who can be credited with creating a marine timekeeper that was inexpensive and simple to make but reliable enough to be used as a longitude finding instrument.
machine, signed 'John Arnold Invt et Fecit London No
12', is thought to be one of the earliest to contain John
Arnold's newly invented version of the
When this machine was made the ship's master or captain would have had to purchase it with his own money. Nevertheless, these simple machines soon became an essential part of the navigator's equipment.
Vaudrey Mercer, John Arnold & Son: chron (London, Antiquarian Horological Society, 1972)
A.G. Randall (revised by R. Good), Catalogue of watches in the -1 (London, The British Museum Press, 1990)