Pocket barometer, the finely engraved 2½” silvered dial with barometric scale from 24–31 inches of mercury, annotated “Rain” and “Fair” with maker’s signature “Callaghan” and address “23a New Bond St, corner of Conduit St, London.” The outer dial with altitude scale to 6,000ft, rise and fall scale +/- 1,000ft. Blued-steel pointer, rotating bezel. Early pattern Vidi-style movement, the primary lever acting on a coiled spring, the secondary lever with temperature compensation, the cock with serial no. “1227” and “11/12/67.” Heavy spun case with suspension loop, compensation port to rear set at 7 o’clock. Contained in its original brown leather case with crescent cut out to front affording a view of the dial.
This is a very interesting and most unusual antique instrument, of early production: ’11/12/67′ the date of manufacture; the movement serial no. ‘1227’ is extremely low; the primary lever is countered by a coil spring rather than the later “C” spring development; the case is of extremely heavy construction having been turned from tube or solid on a lathe. The leather case is also most interesting, having a crescent-shaped viewing slot enabling the user to observe the pressure reading whilst the instrument remains protected in its case.
Many of these very early aneroid instruments lacked serial numbers on the dial, though occasionally a production or serial number is recorded on the movement – this is one such. Though having been dismantled, examined and serviced, this mountaineering pocket barometer remains in absolutely ‘as found’ original condition.
When the barometer was removed from its travelling case for examination, a small newspaper cutting was found, tucked right into the foot of the case. Dating from August 1889, this refers to the fact that Mr. Ralph Abercromby had established a means of measuring the height and length of ocean waves using a sensitive aneroid barometer (on the reverse are details of betting for the Doncaster St Leger which dates the cutting).
Hon. Ralph Abercromby (1842-1897), a Scottish great-grandson of Lt-Gen Sir Ralph Abercromby and a Fellow of The Royal Meteorological Society, was noted for his contributions to meteorology, his travels producing several books, including Seas and Skies in Many Latitudes: or wanderings in search of weather published by Edward Stanford in 1888. It is very fair to assume that this pocket barometer belonged to him.
William Callaghan & Co worked from various addresses in New Bond Street from around 1860 to 1900. William Callaghan died in 1874, and the company ceased trading from the 23a New Bond Street address in 1875.
The brass case retaining almost all of its original lacquered finish, the dial clean and crisp, the leather case and stitching sound. Serviced, in good working order. A real collector’s piece.
Dimensions: 3½” diameter x 1″ deep
Stock No: PB0318
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