Exceptional Horological Works of Art

Geneva, Oct 19, 2002

LOT 148

Breguet, No. 2807, sold to General Yermoloff on August 26, 1817 for 4,000 Francs. Extremely rare and exceptionally fine and elegant 18K gold and enamel astronomical equation of time watch with annual calendar, manual perpetual calendar, phases of the moon and mean and true solar time, in a Morocco fitted box. Accompanied by Breguet Certificate of 1857.

CHF 1 - 1

EUR 1 - 1

Sold: CHF 2,258,500

C. Four-body, "forme quatre baguettes", back centered with engraved with coat-of-arms under pale gray translucent enamel, engine-turned around and on the band and bezel, gold hinged cuvette with winding, regulating and leap-year apertures. D. Silver, by Tavernier, engine-turned, to the left true solar time sub-dial with Breguet numerals, outer minute track and gold Breguet hands, symmetrically to the right mean time sub-dial with Roman numerals, outer minute track and blued steel Breguet hands, phases of the moon aperture above 6 o?clock surmounted with days of the week aperture with its setting aperture to the left, outermost annual date track. M. 53 mm. (23???), gilt brass, going barrel, 21 jewels, straight line calibrated lever escapement with divided lift and straight pallets, banking against the escape wheel arbor, draw, cut bimetallic steel/platinum compensation balance with rims cut in the center, sunk at the center for the double roller, gold and platinum screws, blued steel Breguet balance spring, the annual calendar driven from the gold days of the week wheel, making one revolution in five weeks, equation cam set at the center of the annual wheel, ingenious system of transmitting power from the mean time motion work to the solar time motion work via special double wheel/double rack and pinion mechanism. Signed on the dial and cuvette. Diam. 60 mm.


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Grading System
Grade:
Case: 3

Good
Movement: 3*

Good

Overhaul recommended, at buyer's expense
Dial: 3 - 01

Notes

This remarkable watch possesses an ingenious and simple equation of time mechanism which interferes only minimally with the going train. The equation mechanism engages with the motion work only once every 2 hours, and then briefly, minimalizing the resistance on the train. To achieve this Breguet designed a mechanism whereby the motion is transmitted from the mean time motion work to that of the solar time via a double spring-loaded wheel joined together by a system of two pivoted racks and a pinion. One rack advances the bottom wheel, the other retreats. This is done by a lever controlled by the equation cam mounted on the annual wheel. When the lever closes in, the small dart mounted on the advancing rack pushes the rack, which advances the pinion on the intermediate motion wheel, which in turn transmits the difference to the solar motion work. When the lever retreats, the mechanism takes over and every two hours releases the click holding both wheels together. It retreats until the dart falls on the equation lever. Since the watch is built on the principles of the "garde temps", Breguet apparently wanted to make sure that the forces interfering with the isochronism of his chronometer were kept to a minimum. The equation mechanism is driven from the days of the week wheel which turns once every five weeks. Its extension is fitted with a 20-leaf pinion driving the center annual wheel which carries the equation cam. Another unique feature of the watch is its manual perpetual calendar. The owner needs only to engage the lever protruding through the cuvette once every four years, and the calendar adjusts to the correct day. The watch is exceptionally well finished. Its entire going train is jeweled, the escapement has endstones and is superbly finished. The combination steel and platinum balance, although not unknown in Breguet watches, is reserved for his best pieces. The pallet fork with equidistant pallets, two platinum counterpoised weights, and draw, is well ahead of its time; it became popular in the 1860?s. The sunken center of the beveled and mirror-polished balance arm was specially made to assure that the watch be slim. Indeed, its slimness is remarkable for a watch with such complications. Breguet No. 2807. Equation of time, two-arm compensation balance. Breguet spiral, pare-chute, sweep center date, solar time, mean time, phase of the moon and age, gold case and silver dial, both engine-turned. Drawing published in Professor Thomas Engel?s book "A.L. Breguet, Watchmaker to Kings", 1994, p. 177. The watch is illustrated in the "A. L. Breguet Horloger" by C. Breguet, p. 14. Enfield, England.