On July 7th, 2016 in London during the second part of Sotheby’s series of auctions dedicated entirely to English Watchmaking, a new world record was set for a John Arnold chronometer. The John Arnold pocketwatch numbered 23/78, completed in 1781, fetched a whopping £557,000 GBP ($722,318 USD), multiple times its original estimate. John Arnold is today widely recognized as one of the most innovative and consequential watchmakers ever, which is why this recent sale drew my attention.
The 23/78 is unique for a number of reasons. It features several inventions by John Arnold and other outstanding features including a pivoted detent escapement with a “double S” balance, a cylindrical balance spring, and a clever temperature compensation mechanism. Furthermore, it is the only known example to have survived in its exact original condition without ever having undergone any restoration, with all parts including the silver case, enamel dial and movement perfectly intact and untouched.
Born in Cornwall, John Arnold (1736-1799) is one of England’s most famous and important watchmakers. After being apprenticed to his father, a Clockmaker from Bodmin, John Arnold almost certainly worked for a time as a gunsmith with his Uncle before travelling to Holland where he continued work as a watchmaker’s assistant and it is here that he learned German which doubtless proved a great asset in his later connections with King George III’s court. In 1762 he moved to London and shortly thereafter presented a repeating watch mounted on a ring to King George III. The watch created a sensation and was widely reported upon with details included in the “Annual Register” for 1764 and the “Gentleman’s Magazine” of the same year. It has been suggested by several researchers, including Cedric Jagger in his book Royal Clocks, that John Arnold was encouraged by King George III to “enter the ‘longitude’ arena” and make an accurate timekeeper for use at sea.
Arnold’s first attempt at a marine timepiece was completed in 1768 and presented before the Board of Longitude in 1770. Arnold realised that a detatched escapement would be highly desirable and this led him to invent his early detatched escapement in c.1770, followed by his spring detent (which bears his name) in c.1782. To overcome isochronal variation, Arnold took out a patent for a helical spring in December 1775 and used this with his ‘double T’ and ‘double S’ balances. Arnold realized that a detached escapement would be highly desirable and this led him to invent a detent escapement, circa 1781, which bears his name. In 1787 he took his son, John Roger Arnold, into partnership, changing the business name to “Arnold & Son”, which was retained until his death. A detailed examination of the life and work of John Arnold is given in Vaudrey Mercer’s definitive work on the maker entitled John Arnold & Son, published by the Antiquarian Horological Society in 1972.