English silver half-hunting cased Carrousel watch Circa 1898

Silver half hunter by S. Smith & Son
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A large English silver half-hunting cased keyless pocket watch, circa 1898. With Bonniksen’s patented 52 1/2 minute Carrousel regulator, achieved Class A Certificate, Kew Observatory Especially Good, with a score of 83.3 Marks. A solid, polished case with master mark (SS), the front cover with blue champlevé enamel radial Roman numerals, an inner minute track around the glazed aperture and a hinged silver cuvette. White enamel dial by Marnham, radial Roman numerals, outer minute track, subsidiary seconds and blued steel double spade hands.
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A frosted gilt, three-quarter plate movement, 17 jewels, going barrel, lateral lever escapement, cut bimetallic compensation balance with gold screws, blued steel Breguet balance spring with a terminal curve, diamond endstone, mounted on a Bonniksen 52 1/2 minute Karrusel regulator. Dial signed and inscribed with the rating details, movement signed and punched with Bonniksen’s mark on the pillar plate. The case with London hallmarks.
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Diameter: 56 mm
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Signed: S. Smith & Son  London
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Kew Observatory trials for watches Various testing laboratories around the world were responsible for grading and testing watches. The most stringent being the Kew (Teddington) Observatory, just west of London. A standard Swiss chronometer test would last 15 days, however, the Kew test lasted 44 days. The tests consisted of observing the timekeeping of the watch in various positions and at various temperatures and awarding points for accuracy in these differing states. 83.3 marks is regarded as especially good and does the makers great credit. The eight testing positions were as follows: Pendant up – 67° Dial-up – 42° Pendant right – 67° Dial-up – 67° Pendant left – 67° Dial-up – 92° Pendant up – 67° Dial down – 67°.