Rare Swiss 18k gold column wheel chronograph Circa 1890

Fine and rare gold column wheel chronograph
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A fine and rare Swiss 18k yellow gold open-faced column wheel chronograph, circa 1890, mercury gilt lever movement, cut bimetallic balance with gold peripheral timing screws and blued Breguet balance spring with terminal curb, column wheel chronograph system, 18k yellow gold engraved and engine-turned cuvette.
White enamel dial, Breguet numerals, subsidiary dials for constant seconds and 30-minute register, outer minute track with 1/5 seconds divisions, 18k yellow gold bassine case with monogram R.L on the back, dial and cuvette signed, dial, cuvette and case numbered.
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Diameter: 51 mm
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Signed: Breguet