Important Glashütte half seconds deck chronometer Circa 1914

Silver half seconds deck chronometer by A. Lange & Söhne
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Important silver open faced Glashütte half seconds deck chronometer, circa 1914. Delivered to the Imperial and Royal Hydrographic Institute in Pola in 1914. Engine turned case with gold hinges. Extremely rare chronometer movement with diamond endstone and pivoted detent escapement in manner of Moritz Grossmann, helical hairspring, screwed gold chatons, finest engraved balance cock. Silvered and grained dial with Roman numerals and original hands. Comes with an extract from the archives.
Case and movement with matching numbers.
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Diameter: 63 mm
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Weight: 188 g
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Signed: A. Lange & Söhne Glashütte B,Dresden
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These extremely rare Glashütte chronometers were manufactured for maritime purposes. The watches were constructed with 14400 half oscillations in one hour, so that the seconds hand is able to make half seconds jumps. All have a pivoted detent escapement, which was built in two versions: as a chronometer escapement in manner of Berthoud and as a chronometer escapement in manner of Julius Grossmann with an additional safety lever to prevent the escape wheel from running through after removing the balance wheel.
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According to the Lange & Söhne archives this watch was part of a delivery of 20 half seconds deck chronometers No 64861-64880 to the Imperial and Royal Hydrographic Institute in Pola.
The sister watch 64875 from this delivery was auctioned in May 2018 and was sold for € 45.000.