A rare variant of the Francis Barker & Son ‘RGS’ type prismatic compass, dating from c.1904. Although there are no maker's marks, this is a well-known Barker design which the company supplied to several prominent scientific instrument retailers, including Negretti & Zambra, London, Kelvin & James White, Glasgow, and Davidson & Regenstreif, Cairo. The compass featured in the 1909 Negretti & Zambra catalogue, where it was described as 'Prismatic Compass, pocket size, stout bronzed snap hunter case, card dial, with specially bold day and night luminous centre, revolving lubber line on the glass front, sight in the lid, large finger ring attached to case, and stops for steadying the swing'. The base of the compass is signed by the retailer - 'Kelvin & James White Ltd, Glasgow', who were in business in Glasgow from 1900 to 1913.
This is a particularly rare prismatic design, with elements of both the Schmalcalder Patent design of the early 19th century, and the Singer’s Patent compasses of the 1860’s. It may well have been intended for military use as an officer's private purchase item, and its service pattern leather case, dated 1916, suggests the compass was used during the First World War.
The compass features an aluminium card with a central section hand-painted with Barker's distinctive 'RGS' design. This central section would have been treated with a luminous compound (most probably ‘Balmain’s Luminous Paint’), which was activated by exposure to very bright light, often created by burning a strip of magnesium ribbon. The compass has a 'bronzed' brass case, folding prismatic sight, a transit lock operated by a sliding button on the side of the case, and a manual brake. It comes complete with its fitted leather case and shoulder strap.
Barker's 'RGS' design was a development of the Singer’s Patent design, and is very similar to one illustrated in the Royal Geographical Society’s explorers manual Hints to Travellers (1871). The ‘RGS’ type was often used by travellers and explorers around the turn of the century - Ernest Shackleton took several similar compasses with him on his expeditions to the antarctic, including the celebrated 1907-9 British Antarctic Expedition.
Kelvin & James White Ltd: James White (1824-1884): Founded the company in 1850 as an optical and scientific instrument maker. James White had a long association with William Thomson (later Lord Kelvin), who was Professor of Natural Philosophy at Glasgow University from 1846-1899. White supplied and repaired apparatus for Lord Kelvin's laboratory at the University of Glasgow and collaborated with him on the development of compasses, scientific instruments, and the mirror galvanometer for the Atlantic telegraph project. In 1900 the company was incorporated as Kelvin & James White Ltd, with Lord Kelvin as a director and his nephew, James Thomson Bottomley, also joining the firm. The company became best known for its marine compasses and sounding machines, particularly Lord Kelvin's designs. In 1913 Kelvin & James White Ltd became Kelvin Bottomley & Baird Ltd.
Condition:
In very good condition, and full working order. The compass finds north very well. The glass, compass card, and case are in very good condition. There is some wear to the original bronzed finish of the brass case. The leather case is in very good condition.
Dimensions: 54mm diameter (85mm inc. prism & loop)
