Silver-cased Watch This watch, made by instrument- and watchmaker William Harrison, is a miniature version of his father John Harrison’s Longitude Prize-winning H4 Chronometer design.[1] John had fitted H4 with maintaining power to keep it running to time while being wound. He also reduced the friction in H4 and the requirement for oil in the escapement by using diamond pallets. Roughly 30 years later, William recreated his father’s low-friction diamond pallet escapement by altering the standard verge balance wheel in this watch. While the diamond pallets in his father’s H4 Chronometer watch are only about 4 mm long and 1.5 mm thick, those in this modified jewelled verge watch are comparatively miniscule. John Harrison’s influence does not end here, as his son’s watch also shares attributes with a watch made by the English clock- and watch maker John Jefferys (b. 1701, d. 1754). Jefferys made his watch for John Harrison to Harrison’s specifications. William’s watch is also similar to the so-called ‘portrait’ watch by John Harrison’s son-in-law, Thomas Barton.[2] William’s silver-cased watch has a 30-hour duration and a gilt full-plate movement with five turned-baluster pillars. The minimally elegant dial is of white enamel and features a chapter ring with Roman numerals encircled by an outer minute ring with Arabic numerals. The time is indicated by blued-steel hour and minute hands. The watch’s gilt metal dust cover has survived, and its plain silver inner and outer cases are stamped with the maker’s mark TG and hallmarked London, 1797. TG probably stands for Thomas Gooch, a contemporaneous watch maker in London. Harrison’s signature, W. Harrison, and his serial number, No. 33, are engraved together on the backplate. End Notes [1] Carter 2021, 218–221, Catalogue No. 44; Randall 1992; Taylor et al. 2020, 36, Exhibit No. 4:8. [2] Carter 2021, 218. References Carter, J. 2021. The John C Taylor Collection: Part II (Selling Exhibition Catalogue, Carter Marsh & Co). Winchester: Carter Marsh & Co. Randall, A. 1992. The Time Museum Catalogue of Marine Chronometers. The Time Museum. Taylor, J. C. and K. Leith (with contributions by T Phillipson and K Neate). 2020. The Luxury of Time: Clocks from 1500–1800. Isle of Man: Fromanteel Ltd.
