Lot 236
BRASS ANEROID POCKET WEATHER FORETELLER OR WEATHER WATCH, NEGRETTI & ZAMBRA, LONDON
EARLY 20TH CENTURY
Auction: Five Centuries Day One | Wed 9th September | Lots 1 to 255
Description
the 2 inch circular silvered register calibrated in inches to the circumference around inner ring adjustable for direction of wind via the knurled bezel and central disc rotating via crown within suspension loop for lining up with the blued steel pointer and pierced with three sectors annotated FALL, STEADY & RISE and inscribed ‘PATENT 6276/15, R/160, NEGRETTI & ZAMBRA’, the cylindrical case with altimeter scale and pointer for adjustment by turning the rear bezel to align a pointer engraved into the rim, the rear cover is annotated with 26 sectors describing a weather forecast beside a letter of the alphabet which appear within the relevant sector to the centre of the register, with original red leather travel pouch
Dimensions
5.4cm diameter
Footnote
Literature: Illustrated in Banfield, Edwin BAROMETERS Aneroid and Barographs, page 87, with a full description of its operation on page 89.
This pocket barometer incorporates Negretti & Zambras Weather Forecaster patented in 1915 which was developed using actual weather conditions over a ten year period. By setting the wind direction and lining up the central disc against the steel pointer on the dial, as well as setting the correction for altitude (by rotating the rear cover so that the arrow lines up with the correct level on the scale engraved on the side of the case), the weather can be forecast by reading the letter that appears within the appropriate sector in the centre of the dial taking into account whether the pressure has been rising, falling or remaining steady and the season (summer or winter).