Important Collectors' Watches, Pocket...

Geneva, Mar 16, 2008

LOT 501

Yellow Gold Tourbillon Audemars Piguet, Genève, "Automatic Tourbillon with Power Reserve", No. 4, case No. D 7909. Made in a limited edition in 1994. Very fine and rare 18K yellow gold wristwatch with visible oneminute tourbillon regulator, 60-hour power reserve indication, date and an 18K yellow gold Audemars Piguet buckle.

CHF 40,000 - 50,000

USD 36,000 - 45,000 / EUR 25,000 - 30,000

Sold: CHF 42,000

C. Two-body, solid, polished and brushed, case back with 6 screws, brushed flat band, rounded polished bezel, teardrop lugs, back winder, sapphire crystal. D. White lacquer, with off-center subsidiary dials; on the 12: hours and minutes dial with painted radial Roman numerals, on the 3: days of the month, on the 6: aperture for the tourbillon cage, on the 9: 60 hours power-reserve graduation. Burnished steel feuille hands for the time, blued steel épée hands for the date and power reserve ring dials. M. Cal. 2875, rhodium-plated, oeil-de-perdrix decoration, 41 jewels, titanium tourbillon cage, monometallic balance, self-compensating flat balance spring. Dial, case and movement signed. Diam. 39 mm. Thickness 10 mm.


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Grading System
Grade:
Case: 3

Good
Movement: 2

Very good
Dial: 2-01

Very good

HANDS Original

Notes

Production of this model started in 1993. What is a Tourbillon ? ATourbillon is a regulating mechanism in which the escapement of a movement is housed within a revolving carriage. It was developed in an effort to attain better precision. When a watch is in a vertical position, the force of gravity will speed the balance wheel as it moves in its downward (arc) direction and slow it as it moves upward, creating deviational errors of timekeeping. By placing the balance and escapement in a carriage that revolves 360° per minute, these errors become averaged and the timekeeping becomes constant and consequently adjustable. Created by Abraham Louis Breguet in 1795, the tourbillon is considered a difficult and complex achievement by any watch manufacturer.