German watch with A. Lange experimental movement Circa 1868

Open faced pocket watch by A. Lange
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A very rare German pocket watch with Adolph Lange Dresden experimental movement, early crown winding and big balance, circa 1868.
Engine turned nickel case with reeded mid section. Adolph Lange precision lever movement with gold escape wheel, gold lever, 2/3 main plate and early crown winding. Lateral lever for switching between winding and time setting with vertical shift of the mechanism. Signed white enamel dial with Roman hours, subsidiary dial for the constant seconds and blued steel hands. Main plate signed and numbered under dial.
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Diameter: 52 mm
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Signed: A. Lange Dresden
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The watch is very interesting, as it is on the one hand a watch from the first production years of A. Lange, on the other hand presumably an experimental movement with an early crown winding.