25,300 CHF
R. J. Barth & Fils, Chaux de Fonds, circa 1870. Exceptionally rare, probably unique, 18K gold watch of special construction with two time-zones, dead center-seconds, split-seconds, split-minutes, and split-hours, and a special escapement. Four-body, “bassine” with coin-edge band, both covers florally engraved on engine-turned background, pendant and bow engraved with scrolling, gold hinged cuvette. Notes During the last quarter of the 18th century, several watchmakers tried to produce watches with dead center-seconds hands, much in favor among the scientific community and on the Chinese market. The first attempt, made by Moïse Pouzait around 1786, featured a lever escapement associated with a large seconds-beating balance. It was much appreciated by the Chinese before Jacot's invention, circa 1840, of the so-called "Chinese duplex" escapement with double-tooth arrangement. The Jacot escapement, like any duplex escapement, is a frictional one the friction from the escape wheel is constantly present.The escapement in the present watch is frictionless the balance, when not receiving an impulse, rotates freely. This is achieved by a clever use of Robin's double-locking lever with two sharp pallets which lock and unlock the double teeth. The full cycle requires four swings of the balance: 1. The entry pallet unlocks and the escape wheel delivers an impulse. The balance receives enough momentum to swing about 270º. The exit pallet locks the first half of a tooth. 2. The ex
Auctioneer:
Antiquorum
Date:
2003-10-11