Jacob Auch, Weimar

A VERY RARE GOLD DOUBLE DIALLED ASTRONOMICAL CALENDAR WATCH WITH GEOCENTRIC PLANETARIUM CIRCA 1790

• Movement: gilded full plate with going barrel, cylinder escapement, plain three-arm balance
• Dials: first: white enamel, the edge with Arabic numerals for hours running twice from 1-12 in black and 1-12 in pink, four subsidiary dials for minutes, date combined with month, regulation, seconds combined with days of the week, aperture for winding, gold hands, the hour hand with an additional steel support carrying a square for rapid resetting of the calendar • second: light blue enamel geocentric planetarium dial decorated with gold stars and an outer month ring, various lines of the ecliptic zodiac marked in black, with three concentric hands of steel mounted with the earth, a gold sun and moon, the entire dial revolving once per year, the ecliptic line shown by a polished steel band attached to the engraved silver dust ring
• Case: plain gold moulded bezels
diameter 68mm

Provenance:
Time Museum, Rockford, Il, Inventory No. 1698
Sotheby's New York, Masterpieces from the Time Museum Part II, 19 June 2002, lot 53