Rare French 18K gold lever with power reserve Circa 1900

Gold pocket chronometer with power reserve by L. Leroy & Cie
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A very fine and rare French 18 carat gold open faced keyless lever pocket chronometer with power reserve indication made for the Besançon Observatory Timing Contest, circa 1900. Frosted gilt movement, 18 jewels, wolf’s tooth winding, stamped with the Besançon viper’s head mark, straight-line lever escapement, cut bimetallic compensation balance, blued steel Breguet balance spring, index regulator. White enamel dial with Roman numerals, outer minute track, subsidiary dial for the seconds, sector below 12 for the power reserve, and original gold spade hands. Heavy polished case, flat band. Dial and case signed. Comes with the original Leroy morocco leather-covered box.
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Diameter: 52 mm
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Signed: L. Leroy & Cie Hgers à Paris
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The punch mark in form of a viper’s head is applied by the Observatory of Besançon on watches that were successful at the timing contest and received the Bulletin de Première Classe.