WORLD WAR II: BRITISH ARMY RANGEFINDER.

A Barr & Stroud polished brass British Army Rangefinder. Canada and Glasgow: Research Enterprises and Barr & Stroud, 1944.

A Barr & Stroud polished brass British Army Rangefinder. Canada and Glasgow: Research Enterprises and Barr & Stroud, 1944. Canadian/British manufacture, with the horizontal sighting line tube mounted on a brass mounting, presented on a black metal tripod stand.Sighting tube 43 inches (1110mm), height 53 inches (1350mm); together with a second polished brass unmounted British Rangefinder, unmarked. A few small knocks.

The firm of Barr & Stroud was established as an optical firm in Scotland in 1888. In 1891 they approached the British Admiralty with the idea of their simple optical rangefinder for use in the British Navy, and soon they were their doubling plant size. With the First World War, came new optical devices the periscope, binoculars, dome sights for planes. In the 1930s they added the army version of the rangefinder for artillery use, and by the 1940s they were using a Canadian firm to produce the main parts under licence, presumably due to metal shortages in Britain. The rangefinder is a very simple optical device using the images from two ends of the tube, to calculate the distance of a distant object. These Army Rangefinders were accurate from 250 to 20,000 yards (around 10 miles). Some of the Naval Rangefinders had optical barrels 6-8 feet long to calculate even longer distances.