Important Collectors’ Wristwatches, P...

Geneva, Nov 16, 2008

LOT 495

Pin Wheel Escapement, Quarter-Repeat & Independent Dead Center-Seconds Charles Le Roy, H.ger de S.A.I. Madame (Son Altesse Impériale Madame), No. 772. Made circa 1805. Extremely fine and equally rare, three-train, quarter-repeating, 18K gold pocket watch with pin-wheel escapement and Pouzait-type independent dead center-seconds.

CHF 32,000 - 37,000

USD 30,000 - 35,000 / EUR 20,000 - 23,000

Sold: CHF 28,800

C. Four-body, ?forme collier?, polished, reeded band, bolt at 1 for locking the repeating and at 3 for the start/stop of the center-seconds. Hinged gold cuvette. D.White enamel with Breguet numerals, outer seconds track with gold painted five-second divisions and Arabic numerals. Gold Breguet hour and minute hands and blued steel seconds hand.M. 44 mm., matte gilt, ?calibre à ponts de Lépine?, standing barrel for the going train, fixed barrel for the independent seconds train, pin-wheel escapement with polished steel escape wheel set with fifteen gold perpendicular pins, polished steel anchor and fork acting on a ruby impulse roller, gold three-arm balance with pare-chute on the top pivot, blued steel flat balance spring, bimetallic temperature compensation curb on the blued steel index regulator, Pouzait-type dead center-seconds mechanism, all-or-nothing chain-wound repeating mechanism repeating on rectangular-section gongs activated by depressing the pendant. Dial and cuvette signed. Diam. 55 mm.


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Grading System
Grade:
Case: 3

Good
Movement: 3*

Good

Overhaul recommended, at buyer's expense
Dial: 3-24-01

Good

Slightly chipped

HANDS Original

Notes

Here Le Roy used the pin-wheel escapement very rarely found in a watch, along withmajor horological advances of the day: the Lépine calibre à ponts, Pouzait?s dead center-seconds mechanism and Breguet?s pare-chute shock absorber and temperature compensation curb. These features, as well as the repeating and the gilt on the dial, suggest the watch wasmade to impress amechanically-minded patron. Themovement may have been begun much earlier and, perhaps due to the Revolution, not completed until the early 19th century. Pin-Wheel Escapement The pin-wheel escapement, invented by Amant in 1741, was improved by Jean-Andre Lepaute. Developed for use in clocks, it derives from Graham?s anchor escapement but instead of teeth, pins project at right angles fromits surface. The pin-wheel escapement was relatively easy to make and repair and required only a very small arc. It was extremely accurate in clocks with a half-second beat.
Independent Dead Center-Seconds In 1776 Moise Pouzait invented the independent dead seconds mechanism in which the movement has two trains, one conventional, and the second with a sweep-seconds hand which can be stopped without stopping the main train.