Very Early Negretti & Zambra Barometer No 278 c.1865

A good early three digit serially numbered lacquered brass aneroid wall barometer by Negretti & Zambra No 278 c.1865. Aneroid barometer having 4¼" silvered, engraved and die struck dial, semi circular barometric scale calibrated in inches of mercury with a range from 27.1" – 31.9" divided to 1/100". Standard meteorological terms, the lower part with semi circular thermometer calibrated in degrees Fahrenheit, the register with a range from 20° – 170° divided to 1°. Signed by the maker "Negretti & Zambra, London" with serial no. "278." Fine blued steel pointer, lacquered brass index. The developed Vidie pattern movement driven from a single 2¼" nickel alloy soldered capsule tensioned on a C spring, all raised over a cast iron chassis. The whole contained within a lacquered brass drum form case, pendant and bow, calibration port to verso. Condition: Fully serviced, conserved and calibrated under laboratory conditions, see performance chart from dynamic test. The movement working well across the range with accuracy to 1/10" across the standard range. The dial crisp and clear, some ageing and slight losses to extreme periphery. The thermometer with unbroken thread and recording accurate values to within 1.5° tested at 67°F. The case with some signs of dent having been raised, the bezel with corresponding minor distortion, otherwise crisp retaining most original lacquered finish. Comments: It is likely that this instrument was amongst the first of those produced wholly by Negretti & Zambra, the firm having previously retailed instruments made in France. As such, this is a very significant benchmark in English aneroid barometer making. Very unusual to find, and in much above average condition.