A good and very rare panel or bulkhead mounting forecasting aneroid barometer No 15451 by Negretti & Zambra c1918

Aneroid barometer having 3½” silvered and die struck dial, the outer hand wheel rotated portion marked with Winter and Summer weather prognostications, together with index mark, the inner calibrated in inches of mercury with a range from 26” – 31” divided to 1/10th, the upper part marked  “Compensated for Temperature,” the lower signed “Negretti & Zambra, London,” together with instrument serial no. “15451.”

Japanned light alloy pointer, bevelled glass. The high quality movement dated “30/4/18” driven from a single soldered 2” capsule and tensioned on a C spring, all contained within a light alloy spun case, chromium plated bezel and furniture, the verso with calibration port. The whole presented in its original turned and polished walnut frame with hanging plate.

Condition: The subject of a full service, conservation, and calibration under laboratory conditions, see performance chart from dynamic test. The movement working exceptionally well with maximum error recorded as less than 0.08” across the scale.

The dial with some ageing noticeable to forecasting ring, minor mark to lower right hand quarter otherwise crisp and clear. The outer forecasting dial moving cleanly  through full 360 degree rotation. The chromed parts retaining virtually all original finish being bright and clean, minor marks and losses. The grey painted alloy case retaining much original finish, minor marks and losses. The turned timber surround with good colour, some fading, minor marks and slight losses.

Comments: This is an exceptionally unusual instrument, unrecorded in any of the N&Z catalogues from the period and as such must be regarded as very low production, with the added interest that this is constructed to patterns and probably with surplus parts previously intended for period (WWI) air altimeters.

Unlike similar instruments made by Short & Mason from the same period, this Negretti & Zambra barometer displays both Summer and Winter scales – the former carrying the legends “Falling – for Wet, Warm or More Wind; Rising – for Dry, Cooler or Less Wind,” the latter, “Falling – for Sleet, Snow, Wind or Hurricane; Rising – for Dry, Very Cold or Less Wind.” The dial is also marked “Regd” though we have yet to uncover a Registered Design number for this style of barometer.

With fine aesthetic attributes and practical application, this is most certainly a desirable collectors and connoisseurs piece alike.