A military prismatic marching compass, by Ross Ltd of London, dating from c.1905. It is engraved on the lid, ‘Ross Ltd, 31 Cockspur St, London’. Ross Ltd traded from this address from 1898 to 1913. The compass is in very good condition, with the original bronzed and lacquered finishes of the brass case in good condition. It is in full working order and comes complete with its original fitted leather case.
This is quite a rare variant of this type of early 20th century military night marching compass - larger and heavier than the Verner's patent types. But the most interesting and unusual feature is the way the thumb loop is attached centrally in the base, rather than in the standard arrangement underneath the prism housing. The compass is also noticeably larger than most of this type - 60mm in diameter, rather than the more common 50mm size of most military prismatics of the period. Similar compasses (though standard in size and with a conventional thumb loop) were made by Francis Barker & Son during the Boer War and WW1 eras.
The compass has an aluminium compass card with large black hand-painted markers over a luminous painted paper background. The luminous paint used was most probably a version of 'Balmain's Luminous Paint', which was a compound of calcium sulphide. It was made luminous by exposure to sunlight or by burning a strip of magnesium ribbon near the compass card. It was patented in England in 1877 by William Balmain, and was often used in compasses, before the introduction of radium paint rendered it obsolete just before WW1. This compass has no 'broad arrow' service markings, so it may well have been an officer's private purchase item.
Ross & Co, London: Andrew Ross (1798–1859) founded the company in 1830 at Wigmore Street in London, and from 1840 he began producing camera lenses signed "A. Ross". During his lifetime, the company was one of the foremost British lens manufacturers. After Andrew's death in 1859 his son-in-law, J. H. Dallmeyer, left the firm to establish his own optical company. From 1860 onwards the company was run by Thomas Ross, and became known as Ross & Co. By the 1890s Ross were making Zeiss and Goerz lenses under licence for sale in the UK and the British Empire. Ross Ltd was formed in 1897 with share capital of £120,000, and had premises at 31 Cockspur Street and 111 New Bond Street. Before WW1 Ross and Zeiss had worked quite closely together, and at the outbreak of war the British Government put Ross in control of the newly opened Carl Zeiss binocular and optical factory in Mill Hill, London. In 1917 Ross took over the assets of Carl Zeiss (London) Ltd and moved their offices to the old Zeiss building in Great Castle Street. From around the start of the 20th century Ross were best known as suppliers of optical, scientific and nautical instruments. In 1921 Sir Charles Parsons acquired a controlling interest in the company and took over as chairman. From 1948 the company became part of Barnett Ensign Ross Ltd.
Condition:
The compass is in very good condition, full working order and finds North, although the card moves a little slowly. The transit lock and manual brake are in good working order. The compass card and glass are in very good condition. The rotating bezel turns, but is quite stiff. The original leather case is in very good condition, and has the initials 'S. K.' written on it in ink.
Dimensions: 60mm (diameter: 80mm inc. prism)
