Prismatic compass in dark brown leather case and tan brown leather strap and buckle owned by Geoffrey Gordon Rich during World War One
The compass has a circular dark metal container (brass?) with a double lens at one side. there is a lid on the top of the container that when removed reveals a green compass dial (paper? ) with the makers name in the centre and which floats on gimbals rings. An elongated rectangular brass sight with vertical central string folds up from the side. On the other side of the sight is the small triangular double lens that also folds out. The lens is protected by a small circular plate that rotates out of the way when needed.
Notes on prismatic compasses: first invented by Henry Kater 1811 and improved 1812 by C A Schmalcalder. Advantage is that the prismatic compass makes it possible to look simultaneously at the landscape ie the target overt aline of sight engraved (in a glass window in the lid? different to this one?) and also at the angular values of the compass card through an optical device that can be adapted to the user's view.
Notes on the company : The instrument was made between 1835 and 1915 the period during which the company operated under the name of Troughton and Simms. In 1782 John Troughton purchased Benjamin Coles shop in Fleet Street London enabling him to sell his own signed products and later became one of the most respected firms of instrument makers.
Geoffrey Gordon Rich Lt awarded Military Cross: For conspicuous gallantry and devotion to duty in defence of a post on the left, which he held with fifteen men and two Hotchkiss guns. Although turned and bombed, he retreated inwards and saved the trench system by a local counter-attack. Later, news arriving that the enemy were moving down to a bridge, he was ordered to gallop his troop there, and arriving simultaneously with the enemy, he attacked, drove them back, and re-established the bridgehead.
|Year Range from||1914|
|Dimensions||H-2.5 W-9.5 Dia-7.5 cm|