Swiss silver open faced military pocket watch Circa 1918

Silver watch made for the U.S. Corps of Engineers
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A Swiss silver military keyless winding pocket watch made for the U.S. Corps of Engineers by Ulysse Nardin in Geneva, circa 1918. Polished open faced case made by Huguenin Frères from Le Locle, the back engraved Property of Corps of Engineers U.S.A. No. 5380. White enamel dial with suspended Arabic hour numerals, an outer minute track, subsidiary seconds at 6 o’clock and blued steel skeleton hands. A gilded brass movement with going barrel, gold screwed chatons, 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 a micrometric screw. The dial, case and movement are signed.
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Diameter: 53 mm
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Weight: 97 g
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Signed: Ulysse Nardin  Locle & Geneva
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Movement based on Swiss patent No. 55 231, issued on March 28, 1911, to Uhrenfabrik von J. Rauschenbach’s Erben, vormals International Watch Co., Schaffhausen, for a “Zifferblatt Befestigungsvorrichtung” (a dial fixing device).
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Corps of Engineers, U.S.A. In 1918, several Swiss horological manufacturers like Vacheron Constantin, IWC, Ulysse Nardin, etc., started the production of pocket watches, with or without a chronograph, intended for the Corps of Engineers of the United States Army. Following the U.S. entry into the war in 1917, the Americans set up a purchasing office for equipment for their expeditionary forces, “The American Expeditionary Forces”, which ordered several thousand watches until 1920. Especially designed for engineers, they are made of stainless steel, withstand temperature differences and have luminescent numerals and hands.