Swiss gold open faced keyless pocket chronometer Circa 1918

Gold keyless lever chronometer by Vacheron & Constantin
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A very fine, rare and large Swiss 18 carat gold open faced keyless lever pocket chronometer. Sold in 1918. Frosted gilt movement, 18 jewels, wolf’s tooth winding, straight-line lever escapement, cut bimetallic compensation balance, blued steel Breguet balance spring, swan-neck micrometre regulator. Gold hinged cuvette. White enamel dial with bold upright Arabic numerals, outer minute track, large subsidiary seconds and original gold spade hands. Polished case with sunray engine-turned case back. Dial, case, cuvette and movement signed.
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Diameter: 57 mm
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Signed: Vacheron & Constantin Genève Chronomètre Royal
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The name ‘Chronomètre Royal’ was registered on May 28, 1907, under the number 22193. The ‘Royal Chronometer’ name, for the English-speaking market, was registered on May 8 1908, under the number 23872. The first of these was a series of pocket watches delivered to Brazil. A certain A. Campos, one of Vacheron & Constantin’s agents, had organized a lottery system in which subscribers would pay a monthly fee to take part in a series of draws. The holders of the winning tickets would be given a watch and the other subscribers would be entered into the next draw. This system proved to be so successful that A. Campos delivered a total of 3022 watches between 22 October 1907 and 31 December 1911 – an amazing 80% of the production of the Chronomètre Royal, utilizing the calibre RA22-’73 made during this period. The Chronomètre Royal was made in several sizes, from 12 to 22 lines, and was housed mostly in gold cases, and rarely in silver ones.