Swiss gold chronograph with pulsometer scale Circa 1943

Gold doctor’s chronograph
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A rare Swiss 18 carat rose gold open faced keyless lever pocket watch, made by Patek Philippe in Geneva, circa 1943. With a chronograph, 30-minute register and a pulsometer scale. Hinged gold cuvette. White enamel dial with Arabic hours at 3 and 9 o’clock, an outer minute and fifths of a second track with five minute numerals, an outermost pulsometer scale graduated to 30 pulsations, subsidiary seconds at 6 o’clock and gold hands. A co-axial button in the crown for the start/stop and return-to-zero functions of the chronograph, and a bolt at 11 o’clock to lock the chronograph. A rhodium plated movement, gold wheel train, 23 jewels, eight adjustments, lever escapement, monometallic compensation balance with gold temperature screws, blued steel Breguet balance spring. Dial, case and movement are signed.
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Diameter: 46 mm
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Signed: Patek, Philippe & Cie  Genève
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Accompanied by the extract from the archives.
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Reference 685 was introduced in the late 1930s and utilised the same 13’ movement as the reference 130. The present watch, accompanied by an Extract from the Archives confirming its sale on August 22, 1945, is a very fine example of reference 685.
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A chronograph watch with a pulsations scale on the dial is called a ‘doctor’s watch’. It helps doctors cut down on the time necessary to gauge a person’s pulse and, more importantly, reduce errors. The doctor would simply start the chronograph, count 30 heartbeats and then stop the chronograph to see the patient’s pulse per minute on the red scale without further calculations.