Important Swiss gold one minute tourbillon pocket watch Circa 1931

Gold important watch by Vacheron & Constantin
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An extremely important Swiss 18 carat gold open faced keyless lever pocket watch with a one minute tourbillon, circa 1931. Accompanied by an extract from the Geneva Observatory. A polished case with concealed hinge. The gold cuvette inscribed Certificat de 1ère Classe à l’Observatoire Astronomique de Genève – 1er Prix au Concours de Genève. White enamel dial with Arabic hour numerals, outer minute track, subsidiary seconds and blued steel Breguet hands. Glazed rhodium plated movement, Geneva striping decoration, 19 jewels, wolf’s tooth winding, a one minute tourbillon regulator, the carriage with three polished steel equidistant arms and matted steel bridge, straight line lever escapement, cut Guillaume anibal brass compensation balance with gold temperature adjustment screws, blued steel Breguet balance spring and an index regulator. The Guillaume balance was specially adjusted for the 1931 Geneva Observatory Contest obtaining a first prize. Dial, case and movement signed.
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Diameter: 54 mm
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Signed: Vacheron & Constantin Genève Swiss
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This watch was submitted to the Geneva Observatory in 1931 and won first prize. It was one of a special group of watches, all with tourbillon regulators and all adjusted under the direction of master adjuster E. Olivier & Brahier. The results surpassed all expectations, the first three places in 1947 were taken by Vacheron Constantin and the record was broken with 883.8 points.
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The record that Patek Philippe had held for 13 years, since 1934, was broken. Out of the 30 first places, Vacheron Constantin took half the prizes. All the watches were identical, namely extremely high grade tourbillon regulators made entirely in the factory, superbly adjusted by Olivier or Brahier, aided by the skill acquired through years of experience.

The results of this trial are as follows:
Name of Regulator: E. Olivier
The chronometre No.: 413628
Obtained 846 points out of a possible 1000.
The highest score achieved in this trial was 854 points and the lowest 581.