Silver Pocket Barometer Retailed by Callow c.1920

A very good engine turned silver and silver gilt pocket barometer altimeter thermometer compendium by Short & Mason retailed by Callow, London, c.1920. Silver pocket barometer having 1½” die struck silvered stepped dial, rotating bezel-driven outer altitude ring calibrated in feet with a range from 0 - 8,000ft divided to 100ft, stations at the 1000s. Inner barometric scale calibrated in inches of mercury with a range from 23” – 31″ divided to 20th”. The upper centre dial with standard meteorological terms and retailer's details, the lower portion with semi-circular thermometer set on a decorated register showing degrees Fahrenheit and Celsius with a range of 10° – 130° and -10° - 50° respectively. Fine blued steel pointer set below a bevelled glass. The standard Vidie pattern movement driven from a 1⅛" diameter nickel alloy capsule tensioned on a C spring, constructed principally in lacquered brass and raised over a circular chassis. All contained within an inner spun brass case. The whole contained within a classical heavy engine turned silver lidded desk case, London silver hallmarks to gilded inner lid and interior for the silversmith and retailer “Thomas Callow & Son” and date letter “e” for 1920. Condition: The subject of a full service, conservation, and calibration under laboratory conditions. The movement working well with good sensitivity, accuracy falling away at the very low pressures as can be expected with instruments of this age, see dynamic test performance chart. The dial with some signs of shading to centre, otherwise crisp and clean with good definition. The altitude ring rotating correctly, with some slightly increased resistance at one point. The thermometer reading correctly at 70°F. The silver case crisp and clean, the lid shutting precisely. The hallmarks crisp and well struck. Comments: The barometer undoubtedly the work of Short & Mason, the movement dated "4/7/19" and initialled by the finisher. The silver case hallmarked for 1920 and silversmith Callow of Mount Street and Park Lane. This is a superior quality piece obviously of greater weight than most, with its engine turned decoration setting it aside as an aesthetically attractive piece retailed by one of London’s top purveyors of luxury goods at that time. The gilt finish to the inside lid nicely compliments the silver tones. Very much for the collector or as a special gift.