Swiss brass keyless deck watch with power reserve Circa 1920

Deck chronometer
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A Swiss brass keyless chronometer with 40 hour power reserve made by Zenith, circa 1920. Rectangular shaped precision counter clock, called Exact Time, with screwed bezel . Silvered dial with Roman hour numerals, outer minute track, subsidiary seconds at 9 o’clock, 40 hour power reserve indicator at 3 and blued steel spade hands. Rhodium plated movement, going barrel, straight line lever escapement, cut bimetallic compensated balance with gold poising screws and blued steel hairspring with terminal curve, polished steel index regulator with swan neck spring and precision regulating device for fast/slow by means of an eccentric snail. Dial, box and movement signed.
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Diameter: 86 mm
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Signed: Zenith  Le Locle
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Accompanied by a mahogany box.