Jason Clarke Antiques has dated this piece to the 1910s.
The thermometer is comprised of an oak base with two central holes for it to be fitted to the wall.
The minimum theremometer reads from -20 to 140 Fahrenheit and the maximum from -20 to 130, both containing a small magnetic pin in order to record the highest or lowest point of the reading at any given point. These can be reset to level by the use of a weak magnet when required.
This scarce pattern was advertised by Negretti & Zambra from the 1870’s through to the early 1900s whereafter they cease to appear in their main catalogues. An 1890’s advertisement states, “The outside window bracket thermometer enables the observer to read the highest, lowest and present temperatures from inside the house”.
Negretti & Zambra were a leading name in the production 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.
A great looking and interesting example of a max min thermometer and one that is seldom seen.
Circa 1905
Jason Clarke Antiques has dated this piece to the 1910s.
You can view the stock and full dealer information on the Jason Clarke Antiques Profile Page
Edwardian Self Registering Max Min Window Thermometer by Negretti & Zambra
