Jason Clarke Antiques
Rare Land Aneroid Barometer by Negretti & Zambra, London
For sale an extraordinarily rare Land Aneroid Barometer by Negretti & Zambra of London.
Bearing many of the same stylistic qualities of the very successful Fisherman’s aneroid barometer which Negretti & Zambra developed for Admiral Fitzroy, and was used and issued extensively by the RNLI during the latter part of the Nineteenth Century, this Barometer was conceived as an equally serious instrument for meteorological observation on land.
It is comprised of a painted zinc case with a thick brass spun bezel and bevelled glass protecting a 5 and a half inch, two sectioned dial-plate. The very detailed central dial is divided with concentric scales for Millimetres, inches (28 to 31) and also in centibars on the outer ring, all of which are highlighted with red infill to the engraving. At the base of the inner dial there is also a sea level scale and the centre of the dial has the name, Land Barometer and Negretti & Zambra London – Serial: 3345.
The outer dial is also divided for Centibars and can be adjusted by means of a slide which emanates out from the bezel at the base of the instrument. This silvered scale is contrasted with black infill to the engraving and has various weather type indications around the outer edge. In differentiation from the norm, these indications seek to inform the observer of the average number of days that a particular pressure reading will be experienced rather than what type of weather they should be experiencing.
The reason for the slide is made clear when you consider the height above sea level scale on the inner dial. A red engraved arrow on the outer ring is intended to be set against the elevation measurement and then the readings and indications will become relevant to any given position on land. This also means that the barometer itself should be set for sea level as opposed to current elevation as is normal practice.
This variation in design allows the barometer to be moved to varying locations or observation stations and if the elevation is known, would immediately provide an accurate reading for any given position. A subtle yet ingenious development by this ever-creative company that avoids constant adjustment of the movement itself.
I have never encountered this pattern before and I know of only two others which are kept in the Met Office and Science Museum collections; however, these are somewhat different in design. They were certainly produced for Met Office use and an example was also lent to Sir Napier Shaw (Professor of Meteorology) whilst he was compiling his Manual of Meteorology published and revised between 1919 and 1936. This example is the only contemporary evidence I have yet come across for its existence. Perhaps its lack of domestic appeal, did not entice Negretti & Zambra to produce these in volume.
Unusually, it also seems not to appear in the Negretti & Zambra catalogues of the period but the use of Millibars which was only introduced as a standard in 1914, allows us to deduce that it would have been developed at a similar time to the company’s famous weather forecasting products that are now so highly sought after. It also concurs with the timeframe in which Sir Napier Shaw was publishing his Manual of Meteorology.
A very scarce and beautifully designed aneroid barometer.
Negretti & Zambra were a leading name in the production of meteorological and scientific instruments and have a company history dating back to 1850. Throughout their long and esteemed history they exhibited at British industrial fairs throughout 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. A sad end to a hundred and fifty years of quality manufacturing.
If you would like to read a much more detailed account of the company’s history, please feel free to visit the blog page of my website.