Forecasting Aneroid barometer having die-struck 3¾” dial with barometric range from 28 – 31 inches of mercury, divided to 1/20ths of an inch, the upper portion marked “Forecasting Aneroid,” the lower “Compensated,” signed by the maker “Negretti & Zambra, London” and serial no. “10208.” Fine blued steel pointer set beneath bevelled glass retained in a rotating bezel with index. First quality lacquered brass movement of conventional pattern set on a gilt chassis and driven by a single 2″ capsule. Type two drum form case, the circumference marked with altitude correction scale from sea level to 3,000 feet, altitude index locked to position at crown.

4¾” diameter lacquered brass forecaster of tri-concentric design with easel type stand. Signed by the maker “Negretti & Zambra,” with patent date 1915.

The whole contained within a pigskin over timber green velvet-lined case with separation squab, snap closure and button release.

Condition: The subject of a complete overhaul, conservation, and calibration under laboratory conditions, see performance chart.

The barometer, very clean dial, small mark at 9 o’clock, very minor oxidation at periphery lower outboard of 6 o’clock. The glass with some minor scratches otherwise chip free. The case with some signs of oxidation, minor marks and some discolouration, the verso with some wear minor abrasions and discolouration, the lacquer properly re-touched in vicinity of crown fitting, overall presents well and retains a very good proportion of original finish.

The forecaster very crisp, retaining virtually all its original finish, some marks, abrasions and a patch of oxidation at 11 o’clock, both discs rotating with correct resistance. The verso retaining virtually all its original crackle finish paint, the easel secure. This would appear virtually unused.

The pig skin case the subject of near total restoration as this had completely fallen apart; the leather replaced with precisely the original materials, using period adhesive, the internal velvet remaining original, the flat surrounding the barometer worn and in one place (lower right worn through), otherwise sound and vibrant. The hinges, catch and keeper sound and tight. The restoration conducted some three years ago at Vavasseur Antiques, in a manner completely in keeping with the original.

Comments: These sets made to special order are now almost impossible to find. They were made at a time when Negretti & Zambra were pretty much at the top of their game and represent a period in the production of meteorological instruments when, after significant research, it became possible to produce reasonably accurate forecasts in the home. Reputedly N&Z studied weather data for a period of 12 years to produce the forecaster which, if used correctly, was said to be above 80% accurate.

A facsimile copy of the Directions for Using will be supplied with this Forecasting Aneroid barometer (the original is in our Archive).