Swiss rose gold keyless chronometer clock watch Circa 1870

Rose gold grande and petite sonnerie quarter repeater by Girard-Perregaux
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An extremely fine and important Swiss 18 carat rose gold open faced two train grande and petite sonnerie trip quarter repeating keyless chronometer clock watch, circa 1870. Nickel-plated movement, Geneva striping decoration, double train with differential tandem winding, 29 jewels, gold wheel train, pivoted detent chronometer escapement, cut bimetallic compensation balance, blued steel Breguet balance spring, index regulator, striking and repeating hours and quarters on two gongs activated by a trip slide on the band, Marche/Silence and Petite/Grande sonnerie selection levers under the bezel. Gold hinged cuvette engraved with the technical details and with engine turned border. White enamel dial with Roman numerals, outer minute track and Arabic five-minute numerals, subsidiary seconds and original gold Louis XV hands. Polished case. Cuvette and movement signed.
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Diameter: 51 mm
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Signed: Girard-Perregaux La Chaux-de-Fonds
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Any complication, such as a striking train, affects the timekeeping of a watch, so that watches with striking, repeating or chronographs were not usually regarded as precision watches. This piece is extremely rare because it has a detent chronometer escapement combined with grande and petite sonnerie striking and quarter repeating. The use of the chronometer escapement shows that Girard-Perregaux intended this watch to be a precision timekeeper and as such a great deal of skill would have been needed to make the movement and to incorporate all the functions, yet retain the timekeeping capabilities.
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In grande sonnerie striking, both the hours and the quarters are struck at each quarter. In petite sonnerie striking, ‘ting-tang’ quarters are struck at the quarters, but the hour is struck only at the hour.