Swiss silver watch made for the Chinese market Circa 1800

Silver open faced with special Pirouette escapement
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An interesting Swiss silver open faced key winding pocket watch, made by Du Bois & Fils in Le Locle, circa 1800. With a very rare Pirouette escapement, dead center seconds, a chronograph, and a mock pendulum for the Chinese market. A plain case with a white enamel dial, the small eccentric chapter with Breguet numerals, outer center seconds ring on the border of the bezel and glazed circular aperture for the mock pendulum. Gold hands and steel counterpoised center seconds. A hinged gilt brass, full plate movement with cylindrical pillars, fusee with chain, frictional rest escapement with two parallel crown wheels operating on a single conical pallet carried on the arbour of a wheel gearing with the balance pinion. Large plain brass five arm balance, flat balance spring. Signature on the dial and back plate.
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Diameter: 58 mm
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Signed: Du Bois & fils  Le Locle
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Du Bois & Fils,
In 1785, Philippe Du Bois and his sons founded the Du Bois & Fils 1785 watch company at the family seat in Le Locle. Du Bois had already established extensive business connections all over Europe and America as a cloth merchant, which made things much easier for the start-up watch company. During the 19th century, Du Bois & Fils opened branches in Germany, the Netherlands, Spain and the United States, and business boomed. Due to its proximity to the trade fairs, the German Frankfurt branch was particularly important.
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The Debaufré Escapement, invented by P. Debaufré in 1704, this escapement is distinguished by having two escape wheels which are mounted on the same arbour. The escape wheels are staggered. They interact with a semi-circular, wedge-shaped pallet on the balance staff, which has chamfered edges. The wheels, which alternately rest on the flat underside or escape past it, impart the impulse to the balance.