Forecasting Aneroid barometer of lacquered brass construction, 3⅝” diameter silvered die-struck dial with barometric range from 28 – 31 inches of mercury, divided to 1/10ths of an inch, the upper portion marked “Forecasting Aneroid,” the lower, “Compensated,” signed by the maker “Negretti & Zambra, London” with “N&Z” logogram. Fine blued steel pointer set beneath bevelled glass retained in a rotating bezel with index. Conventional high quality lacquered brass movement driven by a single 2″ capsule. Drum form case, the circumference with altitude correction scale to 3,000’, rotating back and movement with index to altitude, locked to position at crown.
4¾” lacquered brass forecaster of tri-concentric design, having easel type stand. Signed by the maker “Negretti & Zambra,” with patent date 1915, retailed by “A.R. Baines, Optician, Harrogate.” The whole contained within a pig skin over timber green velvet-lined case with snap closure and button release.
Of the many instruments Negretti & Zambra produced, two stand out: the Weather Watch and this, its big brother the Forecasting Aneroid, essentially a much more user friendly version of the Weather Watch, made in significantly small numbers as a special order item only. Negretti & Zambra spent around 10 years developing the forecaster, and, if used correctly, it is as accurate as 80%.
These sets are very seldom seen, and mostly the cases are extremely dilapidated. This case has been the subject of careful restoration using the same materials as would have been employed originally. The case carcass was in pieces and has been reconstructed, the leather outer has been replaced with the correct pig skin skiver, the green velvet interior remaining original, including the very rarely seen double-sided velvet cushion designed to protect the barometer glass from the heavy forecaster housed in the lid. The release button to the front replaced.
The instruments themselves remain in entirely original condition though the barometer has been serviced and conserved. The barometer is sensitive and has good transition. Altitude correction is achieved by turning the crown anti-clockwise – the entire back of the instrument may then be rotated so that the triangular index mark may then be aligned with the required station altitude. The reading shown on the dial will then equate to pressure at sea level.
Small scratch to barometer glass, minor wear and marks to verso but retaining virtually all its lacquered finish, very slight discolouration to extreme lower part of dial. The forecaster retaining both virtually all its lacquered and japanned finish. A very desirable collector’s piece.
Dimensions: 5½” wide x 6” deep x 2¾” high
Stock No: BA0474