Surveying barometer with silvered brass and finely engraved stepped 4½” dial with outer ring Vernier scaled 0-20, the inner scales comprising altitude 0–10,000ft, barometric scale 22–31 inches of mercury. The upper dial centre annotated “Surveying Aneroid,” “Compensated,” the lower portion with maker’s legend “Negretti & Zambra, London,” and “17087.” Fine blued-steel pointer, heavy bevelled glass. Circumferentially mounted magnifying loupe with focus adjustment set to rotate about the altitude scale, the heavy stepped case with lacquered brass vernier position wheel to side, the rear with compensation port and screw set at 4 o’clock. The whole contained within its tan leather and red velvet-lined carrying case with shoulder strap.
These instruments are rarely found in such fine condition. This one, apart from showing some signs of age, shows little sign of use – the quality is uncompromising and it stands on its merits as an example of the highest quality scientific instrument making of its time. With excellent transition and sensitivity, this surveying barometer remains in ‘as found’ original crisp condition, and is without doubt a collector’s piece.
Negretti & Zambra, founded in 1850 as makers of scientific instruments, were the most prolific and leading makers of all types of barometers during the second half of the 19th century. The partnership exhibited at the Great Exhibition at the Crystal Palace in 1851 and won a Prize Medal. Negretti & Zambra held the appointment of instrument-makers to Her Majesty Queen Victoria, Prince Albert and Edward VII, the Royal Observatory and the British Admiralty (see Banfield, Edwin, Barometer Makers and Retailers, 1660-1900).
Dimensions: 5″ wide x 3″ deep
Stock No: BA0289