Fine Swiss silver open faced inking chronograph Circa 1879

Silver inking cylinder chronograph by Patek Philippe 
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A fine Swiss silver open faced inking cylinder chronograph, circa 1879. 3/4 Plate mechanical cylinder movement, 8 jewels, plain three armed brass balance. White enamel dial calibrated for 60 seconds with Arabic numerals, large central hand with ink bowl and discharging pointer and subsidiary dial for 60 minutes register. Plain case, snap on back, the ink discharged by depressing the right button in the band, chronograph activated/stopped by depressing the left button in the band. Case numbered, dial signed.
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Diameter: 57 mm
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Signed: Patek, Philippe & Co Genève