A very unusual early gilt brass pocket barometer altimeter, compass and thermometer compendium by Callaghan retailed by S&B Solomons, London c1865

Pocket barometer having 1¾” silvered and engraved dial with barometric scale calibrated in inches of mercury and a range from 23–31, having stations at inches and divided to 10ths, the upper part marked with standard meteorological terms “Rain,” “Fair” and “Compensated,” the lower signed by the retailer “S.&B. Solomons, 39 Albemarle St, London,” outer altimetric bezel-rotated scale with a range from -1,000ft lower, to 6,000ft higher. Blued steel pointer, bevelled glass, single 1¼” capsule-driven early coil spring tensioned movement no. “3575,” the chassis and case similarly numbered. Drum form case with extension post and suspension ring, calibration port to verso.

Semi-circular mercurial thermometer set on circular ivory register, calibrated in degrees Fahrenheit and Centigrade, with ranges 20 – 120 and -10 – 50 respectively. Centrally-mounted Singers Patent compass having ⅝” floating mother of pearl card with cardinals and intercardinals, marked “Singer’s Patent” with serial no. “13972,” bezel-mounted locking lever.

All contained within its original oxblood moroccan leather over timber, deep blue velvet lined case, finely tooled rims, snap closure on a button release, and together with its extremely rare original case-shaped paper insert entitled “Aneroid with scale of feet.” It details that: “If the 1000 ft. lower be set to coincide with 31 inches, the scale of feet may be used as a fixed scale and will correspond with Professor Airey’s New Table.”

Condition: The pocket barometer altimeter retains much of its original gilded finish with minor losses and wear to the case, fully serviced and conserved, good sensitivity and progression, and in good working order. The compass, an early example of the Singer’s Patent with some losses to hand-painted decoration to card, remains in good working order finding north easily, working compass lock. The thermometer with continuous mercurial thread. The register with good colour and without damage.

Comments: This type of early compendium is very hard to find. Quality throughout is very evident, the barometer and probably the compass and thermometer almost certainly the work of Callaghan, London, made to special order for Solomons. With wonderful aesthetics made at or very close to the introduction of the pocket barometer, an instrument essentially inspired by Admiral Fitzroy on an instruction to Negretti & Zambra, this is indeed a very desirable example of these early instruments, one of the very first true pocket compendia.

The “Professor Airey” [sic] referred to is Sir George Biddell Airy, the 7th Astronomer General. Airy created altitude tables to be used in conjunction with aneroid barometer readings.

Once in a while a gem appears. This is one – rare, early with wonderful aesthetics, and in fine original condition.