German silver half seconds beating deck chronometer Circa 1913

Gold Glashütte watch in quality 1A
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A German half seconds beating deck chronometer delivered to the Imperial Hydrographical Institute in Pola in 1913 for 260 Marks – manufactured in quality 1A.
Silver case, tiered, engine-turned, case design “Jürgens”, gold lateral hinge. Dial is matt silvered, radial Roman numerals, auxiliary seconds, numbered, blued spade hands.
2/3 plate movement, frosted, gilt, blued screws, Grossmann’s pivoted detent chronometer escapement with 2 screwed gold chatons, gold screw compensation balance, blued helical freesprung balance spring, very fine florally hand-engraved balance cock, chatoned diamond endstone on balance, gold-chatoned ruby endstone on chronometer wheel and pivoted detent.
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Diameter: 63 mm
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Weight: 194 g
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Signed: A. Lange & Söhne Glashütte B/Dresden
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Pocket chronometers with barrel
Pocket chronometers are considered to be the precursors to deck watches. Lange & Söhne originally produced pocket chronometers with going barrels for scientific purposes. Often set in wooden boxes, they were to be used as deck chronometers on ships. Following this style the watches were designed with 14,400 alternations per hour; as a result the second hand was able to jump every half second. The watches all have pivoted detent escapements, which were designed in two different styles: one version was the chronometer escapement according to Berthoud, the other the escapement according to Julius Grossmann, which had an additional safety lever to prevent the escapement wheel from going on once the balance had been taken out.