A very rare Francis Barker & Son pocket compass thermometer combination instrument, dating from c.1890. This instrument was known as the 'Combination Compass', and was supplied by Barker to prominent retailers such as Negretti & Zambra from the late 19th century until just before the First World War. In the Negretti catalogue for 1908 it is described as a 'Compass, Thermometer, Magnifier, Reading and Burning Glass. One side of the interior is engraved with the eight compass points, and the ring divided to five degrees, whilst to the reverse side is attached a Thermometer with the divisions engraved on the metal scale. The whole of the centre is transparent. The two sides are constructed of thick optically-worked glass of such a curvature that they act perfectly as a magnifier of good power. The axis of the needle is accurately balanced between the two glass surfaces. This compass is strongly made to withstand hard service, and is of the best quality and workmanship throughout.'
This combination instrument has a substantial gilt brass case and a finely balanced English Bar Needle, pivoting between the two magnifying lenses. The cardinal points are hand painted in red and black, set against a white background. The thermometer is set into the perimeter of the rear of the compass dial, and the hand painted scale is calibrated in Fahrenheit from 30 to 120 degrees. Transparent Barker compass designs are well known, but it is exceptionally rare to find one with an integral thermometer.
The 'Combination Compass' was based on the 'Pebble Lens' design which featured in Barker catalogues from the 1880s until the 1920s. In their catalogue for 1885 it was described as a ‘Cyclists Compass, for use with maps etc’. It was said to be ‘Invaluable to Cyclists, Captains, Military men, and others. Being transparent, the roads on the map are easily seen and the distance calculated. The pebble lens, being best optically worked, makes it a fair sized magnifier of good power, for reading and examining any small object’. By the time the 1907 catalogue was produced, the Pebble Lens compass was being described as useful to ‘Aeronauts, Explorers, Motorists, and Yachtsmen’.
Further details of the Barker Pebble Lens compass design can be found in Trade Mark London by Paul Crespel, available as a PDF at the trademarklondon.com website.
Condition
The compass is in very good condition, full working order and finds North well. The magnifying lenses are in very good condition. The gilt brass case and English bar needle are in very good condition, with some wear to the original gilt finish. The thermometer is in very good condition and in working order.
Dimensions: 50mm diameter, 15mm depth
Francis Barker & Son: were established in London in 1848, as a maker of compasses and scientific instruments. The company soon became recognised as one of the most important scientific instrument makers of the time. Francis Barker produced a very wide range of compass designs over the years, supplying major retailers such as Negretti & Zambra, J. Lizars, C. W. Dixey, Dollond, and many others. The company prospered until 1932, when it was taken over and became F. Barker & Son (1932). After WW2 the company changed hands several times and the name is now owned by Pyser Optics of Edenbridge in Kent. They continue to produce the renowned Barker M-73, widely acknowledged to be the world's finest prismatic compass.
