Swiss watch with jumping center seconds and date Circa 1800

Silver open faced pocket watch
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A technically very interesting Swiss pocket watch with very rare double wheel duplex escapement, jumping center seconds and date, circa 1800.
Silver case with removable back cover, a small engraved monogram, reeded mid section and engine turned.
Fire-gilt full plate movement with big, 3-armed, very slowly swinging balance and very rare escapement, variant of duplex escapement with 2 wheels arranged one above the other. Original enamel dial, jumping center seconds, above the date hand, below the minutes and hours, Arabic numerals, Breguet hands.
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Diameter: 50 mm
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Weight: 81 g
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Signed: No name
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The watch is an absolute rarity for technically interested collectors. We are not aware of any other comparable piece with this rare escapement and additional jumping second.