Negretti & Zambra Pocket Barometer Travel Compendium c.1940

A rare pattern cased lacquered brass aneroid pocket barometer no 17479 and thermometer travel compendium by Negretti & Zambra, London c1940. Pocket barometer having 2” silvered and die struck dial, outer bezel activated altimetric ring calibrated in feet with a range from 0 – 8,000ft and divided to 50ft, inner barometric scale calibrated in inches of mercury with a range from 23 – 31” and divided to 20ths. The centre marked “For Direct Reading” and “Compensated,” the lower part signed by the maker “Negretti & Zambra, London,” with serial no. “17479.” Blued steel pointer, bevelled glass. Conventional 1¼” single capsule driven frosted brass movement tensioned on a C spring. All contained within a drum form case, extension post with suspension ring, calibration port to verso. The thermometer mounted to a faux ivory (ivorene) register with twin scales in degrees Fahrenheit, having a range from 30 – 110 degrees. Both instruments presented in a square burgundy cloth covered case trimmed internally with blue satin and velvet. Snap closure on a button release. Together with a possibly official typed guide for usage. Condition: The pocket barometer the subject of a full mechanical overhaul, servicing and calibration tests under laboratory conditions. The movement working well with acceptable levels of accuracy across the standard range, the pressure sensing capsule a replacement. The barometer dial clean and crisp, some signs of ageing, the bezel operated altitude ring moving freely. The lacquered brass case in very good condition, with few signs of wear, retaining virtually all its original finish. The cloth covered case sound, externally with losses to colour, the internal fabric with good colour and in good condition. The case catch working well. The thermometer in all round good condition and working correctly. The instruction sheet split and discoloured, though complete. Comments: This is a very unusual presentation and the first such seen - it might be assumed that these were only offered in very small numbers and as such must be very collectable. The additional benefit is the instruction sheet, probably supplied by the retail outlet from which the instrument was purchased. As an unusual example of Negretti & Zambra’s offering, a collector’s piece.