R.A.F. Bigsworth Chart Board, Type 'B', MK.2. Stores reference 6B/137. Manufactured by E.R. Watts & Sons Ltd., London. Wooden plotting board approximately 43.5 x 43.5cm fitted with a hinged articulated brass plotting arm and adjustable perspex rules. Marked to reverse with Air Ministry King's crown stamps, 1940 date code and later 1953 re-issue date. The board has quite minor scratches, scuffs, marks and wear but is in very good '+' overall condition. The plotting arm is also in very good useable/working condition although the rule doesn't lie completely flat to the surface. The board retains the often missing canvas pen pocket and elasticated hanging loop. These chartboards were used by aircrew navigators to plot routes during flight. With original box of re-issue. E.R. Watts was founded in 1856 and merged in 1948 to form Hilger and Watts. A lovely display item. Stock code M27205.