Antique Pocket Barometer by Callaghan No 4482 c.1875

A scarce numbered lacquered and gilt brass aneroid pocket barometer, altimeter and thermometer compendium by Callaghan No 4482 c.1875. Pocket barometer having 1¾” silvered and engraved stepped dial, the outer bezel operated altitude ring calibrated in feet with a range from 0 - 7,000ft, +/- scale and centred index for 1,000ft, all divided to 100ft. The inner barometric scale calibrated in inches of mercury with a range from 23" – 31" divided down to 1/20th, inset semi-circular thermometer, the register calibrated in degrees Fahrenheit showing 30° – 120°. Blued steel pointer, bevelled glass. The early Vidie pattern movement driven from a single 1” capsule tensioned on a coil spring, the cock struck with serial no. "4482." All contained within a drum form brass case, engine turned and raised finisher to bezel. Pendant and suspension ring, calibration port to verso. Presented in its correct oxblood leather over timber, green velvet and silk lined clamshell case, snap closure on a button release. Condition: Fully serviced, conserved, and calibrated under laboratory conditions. The movement working acceptably well, see performance chart from dynamic test. The dial re-silvered, the brass case retaining much original lacquer and gilding, the leather case structurally sound, sides re-trimmed, the catch repaired. The fabric interior with good colour, though showing wear and signs of age. Comments: Presenting well, this instrument is one of the few surviving numbered early Callaghan pieces, scarce, particularly with the thermometer on the dial, and in good condition. An ideal gift.