Swiss lever for the British Hydrographic Service Circa 1940

Silver indirect centre seconds deck watch by Vacheron & Constantin
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A very fine, rare and large Swiss silver open faced indirect centre seconds keyless lever deck and pocket chronometer made for the British Hydrographic Service, circa 1940.
Gilt brass movement, Geneva Striping decoration, 21 jewels, straight-line lever escapement, Anibal-brass Guillaume balance with special alloy Breguet balance spring, swan neck micrometric regulator. Hinged silver cuvette. Brushed silver dial with champlevé Arabic numerals, outer minute divisions, outermost seconds track divided into fifths and original blued steel spade hands. Polished case. Dial, case and movement signed, back of the case engraved H.S.- 2 55014, case and movement numbered. Accompanied by the Extract from the Archives.
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Diameter: 60 mm
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Weight: 163 g
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Signed: Vacheron & Constantin Genève Swiss
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An excellent example of a Vacheron Constantin deck chronometer, made for the British Hydrographic Service, excellently finished and in very good condition. The worldwide pre-eminence of the Royal Navy in the 19th century meant that Admiralty charts became the global standard for all ships, whether warships or merchantmen. The Hydrographic Service was the surveying arm of the Royal Navy. In the early 19th century, Navy Hydrographer Thomas Hurd persuaded the Admiralty that surveys at sea would best be carried out by Royal Navy ships. For surveying purposes, the Service needed top quality timekeepers, such as this piece.