A very rare bright plated brass cased mining aneroid pocket barometer altimeter by J.J. Hicks, London c1885

Pocket barometer having 1¾” die struck and silvered dial, the outer crown operated altitude ring calibrated in feet divided to 25ft, marked “Ascent” and “Descent,” bi-directional scales to 5,000ft, inner barometric scale calibrated in inches of mercury with a range from 26” – 36” divided down to 1/20”. The upper part marked with standard meteorological terms, the lower signed by the retailer with London address. Blued steel pointer, bevelled glass.

The standard Vidi pattern movement driven from a single one inch capsule tensioned on a C spring. All contained within a semi-barrel form bright plated brass case with engine turned finishers, case extension and crown with integral suspension ring. The verso with calibration port and engraved “K.H.H. Allen.”

Condition: Fully serviced, conserved, and calibrated under laboratory conditions, the movement working well, see performance chart. Generally fair condition, the dial poor with losses. The bright plated case with marks, wear and abrasions. The glass replaced. Included here because of its great rarity.  

Comments: This is almost certainly a one-off order or commission, the dial lacking any serial number. Instruments of this type with scales running in excess of 31” are rare and this one might suggest use in the very deepest mines of the time.

First mention of a portable mining aneroid barometer from James J. Hicks was made in his Illustrated Catalogue of Meteorological and Scientific Instruments, c1870 – a slightly larger pocket instrument, at 2½” in diameter, and with a range from 2,000ft below sea level to 6,000ft above. However, this watch size aneroid instrument was almost certainly made by Francis Barker, a very respected manufacturer who was predominantly a supplier of white label instruments to the trade, and it is known that, apart from thermometers, Hicks bought in the vast majority of the instruments he supplied.

An extremely interesting and very rare instrument worthy of any serious collector.