Swiss 18K gold chronograph open faced watch Circa 1925

Gold keyless lever pocket watch by Patek Philippe & Co.
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A rare Geneva doctor’s watch with chronograph, 30 minute counter and pulsation scale, circa 1925. With original box and certificate.
18 Carat gold, polished, à goutte case with engraved monogram RR, numbered and signed gold dome, pusher for chronograph via the crown, and slide to stop the balance at 11. Signed enamel dial with Arabic numerals, auxiliary seconds, 30 minute counter at 12, outer red pulsation scale, and blued spade hands. Signed, rhodium-plated bridge movement with Geneva Stripes decoration, very finely ground and bevelled chronograph steel parts, ratchet wheel, gold screw compensation balance, and index spring fine adjusting device.
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Diameter: 52 mm
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Weight: 105 g
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Signed: Patek Philippe & Cie. Genève, Suisse
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With a Patek Philippe Certificate of Origin, an Extract from the Archives and a presentation box. The present watch is a rare example featuring a dial specifically calibrated for pulsations. It is also named as “doctor’s watch” due to the pulsation scale on the dial; the scales are calibrated to show heart rate after counting 30 pulses. This particular model was specially adjusted with a half chronometer balance to warrant further precision and accuracy to the watch.