Above is a very rare example of a signed Barker pocket barometer/altimeter.
F. Barker & Son were one of the most prolific wholesale barometer makers in England between the 1880s and the 1930s, but apart from military supplies and private orders, all their different barometers remained unsigned to allow the retailers to sign them and sell them as their own (branding), a practice still in common use today.
Many barometers signed and sold by companies such as John Lizars, Negretti & Zambra, J.H. Steward, C. W. Dixey, L. Casella, to name but a few, would have actually been manufactured by F. Barker & Son.
This barometer is an unusual size for a pocket barometer at 70mm diameter. It was supplied in a Morocco leather case made by Thomas Weeks & Co, who made all the cases for Barker instruments.
The barometer is signed "Made by F. Barker & Son for Thacker, Spink & Co. Simla".
Thacker, Spink & Co, the client who ordered this barometer/altimeter, was a well known Calcutta publishing company. Its directories are well known and comprehensive. In particular, Thacker's Bengal Directory, which was published from 1864 until 1884, covered the presidency of Bengal, but from 1885 was expanded to cover the whole of India and its title was changed to Thacker's Indian Directory. It continued to be published until 1960.
Thacker, Spink & Co. did not have an office in Simla until 1885, so this Barometer would have probably been made to order and supplied in time for the opening of the Simla office in 1885.
Lacquered brass case; diameter 70mm, depth 28mm, Silvered, signed dial with blued steel needle and revolving altitude bezel calibrated to 15,000 feet. Morocco leather case lined with silk and velvet, hinged lid. The photograph below clearly shows, once again, how used paper was recycled in the making of compass dials and instrument cases.
"Charm" Aneroid, diameter 29mm. Revolving altitude scale to 6,000 feet. Pebble (magnifying crystal) front. Made in 18ct, 15ct, 9ct gold and in silver. This one is hallmarked FB&S 18ct Gold London 1895. It is a miniature pocket barometer/altimeter. The bezel ring rotates to set the altitude, which is calibrated up to 6000 feet, and the barometer is calibrated in inches of mercury. This is an extremely rare item, made in such few numbers that this is believed to be the only surviving example. To construct, by hand, a completely accurate and working aneroid barometer in a 29mm diameter case is a masterpiece of instrument making, and it was achieved 114 years ago.
THE MECHANISM OF THE ANEROID BAROMETER AND ITS USES
Extract from the F. Barker & Son 1907 Trade Catalogue explaining how aneroid barometers / altimeters are made, and how they work. Click on the following link to view the full text in a fully printable and downloadable pdf file.
