Rare Pocket Barometer by John Browning No 592 c.1870

A very good rare aneroid pocket barometer by John Browning no. 592 c.1870. Pocket barometer having 3” silvered and engraved dial, engine divided barometric scale calibrated in inches of mercury with a range from 22” – 31” divided to 1/100th. The upper part signed by the maker “John Browning, London” with serial no. “592,” the lower annotated “Compensated.” Fine blued steel pointer, rotating bezel with barb index, bevelled glass. Conventional Vidie pattern movement driven from a single nickel alloy 1¾” diameter capsule tensioned on a C spring. All contained within a drum form case, pendant and bow, calibration port to verso. Condition: The subject of a full service, conservation, and calibration under laboratory conditions, see performance chart from dynamic test. The movement working and responding to pressure with good sensitivity, given its age. The dial very crisp, minor area of discolouration at 6 o’clock beyond the scale. The outer case retaining a good proportion of original lacquered finish, with wear and light abrasions. Comments: The product of a fine maker whose output of such instruments was very limited. Very much a collector’s piece.