A fine scarce burr walnut sloping cased aneroid desk barometer by Ross, London c1880

Desk barometer having 4½” silvered, engraved and die struck dial, the upper part with semi-circular barometric scale calibrated in inches of mercury with a range from 28” – 31” divided down to 1/100, the inner with standard meteorological terms and “Compensated.” The lower with semi-circular thermometer set on a register calibrated in Fahrenheit’s scale with a range from 20° – 130°. Fine cross and circle double tapered blued steel pointer, set beneath a bevelled glass, gilt brass index.

Standard configuration Vidie pattern movement driven from a single 2” nickel alloy capsule tensioned on a C spring. The whole contained within a brass drum form case, pendant and hanging ring. Calibration port to verso.

Presented in its burr walnut veneer deep blue velvet lined sloping front desk case, glazed observation port, lock with escutcheon and key.

Condition: The subject of a full service, conservation, and calibration under laboratory conditions, see performance chart from dynamic test. The movement working exceptionally well with a maximum recorded error of 0.05” across the range; very sensitive with stepless progression.

The dial about perfect, slight marking and signs of age only really visible with specific incident light. The brass case crisp and clean, retaining virtually all its original lacquer finish, minor wear to finish, slight distortion in locality of pendant to verso at one point. The glass appearing damage free.

The desk case with some shrinkage cracks to veneer, the lacquered finish worn in places, generally crisp with excellent colour, structurally sound. The velvet interior in excellent order with what appears to be pretty much the original colour density. Working lock and key.

Comments: These desk barometers appear occasionally. Almost all are earlier Dent, Paris instruments – later examples of this quality and condition are very unusual. Although badged as Ross, it is possible that this piece was manufactured by Negretti & Zambra who in that period were making some of the finest instruments available anywhere in the world. The finely divided dial and obvious quality of the movement all point to an instrument of exception.

Generally this is a really fine example that, given its age and scarcity, would be extremely difficult to better. A wonderful, aesthetically most attractive addition to any work space or room with history, science and practicality all combined. Most collectable.