French gold lever watch regulated by Jules Golay Circa 1880

Gold repeating independent centre seconds lever by LeCoultre
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A very fine and very rare, heavy French 18 carat gold open faced minute repeating two train keyless lever pocket watch with independent centre seconds and double gold wheel train, regulated by Jules Golay and tested by the Besançon Observatory in 1881 recording a variation of 3 seconds in 24 hours, circa 1880. Finished by Louis Laclef, Fabricant a Besançon. Sold by Ed. Loel, 59, Rue des Francs- Bourgeois, to M. Foucher on May 1, 1899 for 1000 Francs. Rhodium plated movement, 46 jewels, two train with tandem winding, double gold wheel train, counterpoised straight-line lever escapement, cut bimetallic compensation balance, blued steel Breguet balance spring with overcoil, index regulator, repeating on gongs activated by a slide on the band. Gold hinged cuvette engraved with the technical details and with engine turned border. White enamel dial with royal blue Roman numerals, outer red minute track and blue Arabic five minute numerals and gold Louis XVI hands. 880Polished case, button at 11 for the handsetting, the start/stop for the centre seconds in the crown. Signed by on the cuvette. Accompanied by the original hand written Besançon Observatory certificate dated August 8, 1881 and signed by Jules Golay, original Loeb receipt and repair bill dated 1906.
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Diameter: 55 mm
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Signed: LeCoultre
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This watch is exceptional in that it was submitted for Observatory testing, this is highly unusual for a watch that has both repeating and two trains because any added complications in a watch are likely to affect the timekeeping properties of the watch adversely. This watch was obviously very highly regarded and its potential as a timekeeper noticed by the maker. It was regulated by the great Jules Golay himself and he recorded that is had a variation rate of 3 seconds over 24 hours. The survival of the original Besancon certificate signed by Golay is extremely rare for a watch of this date. With the single button in the crown for the start and stop of the centre seconds, this watch can be used to all intents and purposes as a chronograph but of course without the return-to-zero function.
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Independent Centre seconds. In 1776, in Geneva, 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.