English deck watch of British Ministry of Defence Circa 1917

“Fishtail” caliber with original wooden box
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An extremely rare Schaffhausen deck watch of the British Ministry of Defence, Hydrographic Dept. executed legendary “ fishtail” caliber – with original wooden box, circa 1917. Steel case, polished, reeded screw back, military engraving. Enamel dial, Arabic numerals, centre seconds, “broad arrow”, blued spade hands. Bridge movement so-called “ fishtail calibre”, frosted, gilt, chatoned, indirect centre seconds, “Patent 55231”, screw compensation balance, index spring fine adjusting device.
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Diameter: 51 mm
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Weight: 101 g
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Signed: International Watch Co
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This is one of the most successfull watch movement designs ever made. The aesthetical beauty of this construction is unmatched. At the same time, this is one of the rarest IWC-works, of which only 600 pieces were produced.