A scarce double-sided pocket barometer, altimeter, numbered Singer’s Patent compass, and thermometer compendium no. 6127 by Negretti & Zambra c1870

Aneroid pocket barometer having 2” silvered, die struck and engraved dial, outer engine-turned bezel-set altitude ring calibrated in feet on the Airey scale with a range from 0 – 20,000ft divided to 100ft, the upper part marked “Compensated,” the lower signed by the maker “Negretti & Zambra, London” and serial no. “6127.” Blued steel pointer, bevelled glass.

Vidie pattern movement driven from a single 1⅛” nickel alloy capsule tensioned on a C spring. Contained in a stepped drum form lacquered brass case, pendant and bow. The verso with calibration port, circular thermometer set to a register calibrated in degrees Fahrenheit with a range from 10° – 160° divided to 2°., and hand decorated mother of pearl Singer’s Patent compass no. 27306 to centre, with bevelled glass and transit lock.

Presented in its original brown leather over timber, green velvet and silk lined double-sided clam shell travel case, the lid silks marked with Negretti & Zambra logograms surmounted by the Royal Warrant. Snap closure on button releases.

Condition: The subject of a full service, conservation, and calibration under laboratory conditions, see performance chart from dynamic test. The pocket barometer altimeter working exceptionally well across the range.

The barometer dial with some light scratches – though these appear dark in the images, they are silvery and less noticeable, otherwise crisp and clean, the compass swings freely and easily finds north, compass lock working. The thermometer reading 4° high measured at 73.6°F. The brass case retaining most of its original lacquer, remaining bright and vibrant. The travel case structurally sound, the subject of some repairs including snap catch. The interior fabric with some fading and discolouration, worn overall but sound and with good colour.

Comments: This double-sided compendium with its numbered Singer’s Patent compass, one of the very last 27,000 or so compasses manufactured whilst Samuel Berry Singer still held the patent on his iconic design, is very scarce, particularly to 20,000ft and with its original travel case and gold block logograms.

Though not perfect, this is a lovely item, a wonderful commentary on the must have gadgets of Victorian society. Very collectable.