Antique Pocket Barometer Altimeter in Desk or Travel Case c.1880

A very good lacquered brass aneroid pocket barometer altimeter retailed by Chadburn’s Ltd, Liverpool with fruitwood travel desk stand c.1880. Pocket barometer having 1¾" silvered and die struck dial, the outer bezel operated altitude ring marked "Higher" and "Lower" with a range from 0-6,000ft divided down to 50ft, inner barometric scale calibrated in inches of mercury with a range from 24" – 31" divided down to 1/20". The upper part marked with standard meteorological terms and "Compensated," the lower signed by the retailer "Chadburn’s, Opticians, Liverpool." Blued steel pointer, bevelled glass, Whiteside-Cook compensation system with rotating back, locking screw. Standard configuration movement driven from a single 1" nickel alloy capsule tensioned on a C spring. The cast iron chassis with maker’s marks "J.P., No 36" to verso. The whole enclosed within a semi barrel form lacquered brass case with turned finishers. Pendant and bow. Presented in a sliding and folding fruitwood desk or travel case. Condition: The subject of a full service, conservation, and calibration under laboratory conditions. The movement working exceptionally well between 26" and 31", drifting at pressures below 26" – this is entirely normal for instruments of this type and age. The barometer dial clean and crisp, some slight ageing. The brass case retaining much original finish, some tarnishing and losses, small scratch to verso. The desk case opening and closing easily, good external colour and well figured timber. The inner blue velvet lining faded with losses. Comments: A handsome instrument, working well and in good crisp overall condition. The timber case is quite unusual and adds both interest and utility. The movement unsigned, but by Negretti & Zambra. This pocket barometer would be a very special and thoughtful gift.