Fine Swiss gold chronograph lever watch Circa 1878

Gold chronograph watch by Patek Philippe
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A fine and rare, 18K gold pocket watch with single button chronograph, circa 1878. Unusual bridge movement, nickel plated, 23 jewels, wolf’s tooth winding, counterpoised and calibrated straight line lever escapement, cut bimetallic compensation balance, blued steel Breguet balance spring, index regulator, steel chronograph work mounted on the backplates activated by a single button in the crown, chronograph locking slide in the band.
Polished case, the back cover with engraved foliate monogram. Dedicated hinged gold cuvette.
White enamel dial with radial Roman numerals, outer minute track and concentric fifths of second scale, Arabic five minute numerals. Blued steel ?spade? hands. Case and cuvette signed.
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Diameter: 49 mm
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Signed:  Patek Philippe & Co.  Genève