Exquisite small French gold world time pocket watch Circa 1850

Gold open faced pocket watch by (Horlogerie Bu..tée)?
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An exquisite small French pocket watch with world time indicator, circa 1850.
Engine-turned 18-carat gold case with cartouche. Enamel dial with applied Roman numerals, outer minute track, enamelled red and black city names radiating from the gold centre of the dial, and gold spade hands. Bridge movement, keywind, three-arm brass balance.
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Diameter: 44 mm
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Weight: 63 g
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Signed: Horlogerie Bu..tée, Paris
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This watch is particularly striking because of the delicately enamelled red and black city names radiating from the gold centre of the dial.