Miniature silver pocket barometer having 1¼” silvered and die struck dial, the outer crown operated rotating altimetric scale calibrated in feet with a range from 0 – 8,000’ divided to 50’, inner barometric scale calibrated in inches of mercury with a range from 23” – 31” and divided to 1/10th”. The upper part marked “Improved Scale, Compensated,” blued steel pointer, bevelled glass. Conventional pattern movement driven from a ¾” single capsule tensioned on a C spring and dated “4/13.”
Contained within a silver semi barrel-form case, extension post, suspension ring, crown, calibration port to verso. All contained within its original buff pigskin over timber, red velvet and silk lined case, snap closure on a button release.
Condition: The subject of a full service, conservation, and calibration under laboratory conditions. Working well with easily acceptable levels of accuracy across the normal barometric range, see performance chart. Exceptional, near perfect dial. The silver case damage-free with virtually no signs of wear, crisp clear hallmarks. The altitude ring moving freely. The glass replaced.
Comments: These miniature instruments are extremely had to find, those in silver cases even more so. Manufactured by Francis Barker, an indication of top quality.
Very much a collector’s item.
Dimensions: 1⅞” diameter x ⅞” deep
Stock No: PB1851