Important Wristwatches, Watches & Clocks

Geneva, Hotel Des Bergues, Oct 14, 1990

LOT 394

Jacob Auch, Weimar, circa 1798. Fine and extremely rare 18 ct. gold double face astronomical watch.

Double body glazed Louis XVI case, the bezels with finely engraved decoration. White enamel dial on the front face with a double twelve hour chapter ring in red and black Arabic numerals, four night and day hours, subsidiary rings for minutes at 12 o'clock, seconds at 3 o'clock, date at 6 o' clock and months at 9 o'clock. Gold poker and beetle hands. The hour hand is set with a square on a gold additional support, for a rapid setting of the planetary. Pale blue enamel dial on the rear face, revolving once a year, representing a geocentric projection decorated with gold stars with outer annual calendar ring and the various lines of the ecliptic, Zodiac, equinox etc... Off set three concentric hands, the sun and the moon represented by their gold symbols. The ecliptic line is represented by a polished steel arm attached to the gilt brass dust ring. GiIt brass full plate movement with going barrel, cylinder escapement with a plain brass three armed balance. In very good condition. Diam. 70 mm. The astronomic dial on the rear face of the watch is driven by means of an additional wheel from the center wheel pinion. The functions shown are the rotation of the sun an the moon about the earth, sideral and mean time, and the annual revolution of the zodiac. The accuracy of the mean/sideral trains is of the order of 0.013 %. Very similar watch in The Time Museum (Rockford, Illinois U.S.A.). Jacob Auch, Seeberg, born 1765. Weimar 1798, died 1842. Court Clock-maker, published two books on horology. A large gold astronomical watch by him is in the Schloss Museum (Berlin).