Jason Clarke Antiques
Rare Leather Cased Forecasting Aneroid Barometer by Negretti & Zambra London
For sale, an immaculate and very scarce large leather cased forecasting barometer by Negretti & Zambra
The instrument is contained within its original morocco leather and gilt tooled hinged case with push catch to the front. The navy blue velvet interior is fitted to accurately house the instrument in the base.
The case holds a large four inch dial barometer with scale reading for 28 to 31 inches of barometric pressure and an extremely fine blue steel pointing hand. The silvered dial is engraved with “Forecasting barometer” to the top and below with “compensated” to denote that the barometer compensates for changes in temperature and the makers name and serial, “Negretti & Zambra, London. No: 9077” and logo below.
The very substantial inch and a quarter deep case is engraved with an “altitude in feet” scale around the circumference which is operated by loosening the pocket watch type knurled dial at the top which releases the back of the case. The reverse dial can then be adjusted to point to the appropriate height above sea level and in turn moves the barometer hand in order to set it for accurate measurement in the given area of the country in which it is beng operated. Once the adjustment is made, the top screw is then tightened back up. The front face can also be hand adjusting to allow a small pointer incorporated into bezel to be aligned to a given point and record the barometer reading. This would allow comparison with the succeeding measurement. It retains all of its original gilt lacquer throughout.
Negretti & Zambra’s patent weather forecasting range was a revelation in its time, this barometer would have been paired with one of Negretti & Zambra’s desk or pocket weather forecasters and would have provided the most accurate portable weather forecasting kit of its day and arguably that ever existed. Sadly radio and later television forecast put pay to this ingenious invention but they reamin the most sought after of Negretti & Zambra’s pieces.
Rarely encoutered today and even more seldom seen in this supreme condition.
Negretti & Zambra were a leading name in the production and retailing of meteorological and scientific instruments and had a company history dating back to 1850 although their parents were amongst those Italian emigres that bolstered the British meteorological instrument making industry at the turn of the century.
Throughout their long and esteemed history they exhibited at British and international industrial fairs and became makers to both Queen Victoria and Edward VII. Owing to changes in the business, the firm ceased the public retailing of scientific instruments sometime around the late 1960’s and continued with a focus on the aviation industry in numerous guises until its eventual liquidation in the year 2000. They are today perhaps the most collected of the scientific instrument firms which bears testament to the quality of their work.