Butterley Company correspondence file with the British Standards Institution on standard designs and specifications Including draft specifications for flameproof electric light fittings, bolted flameproof cable-couplers, protective toes of boots used for industrial purposes, test sieves, flameproof plugs and sockets, cable glands and sealing boxes for use in mines, goggles for protection against flying fragments, and standards for sockets for wire ropes and paper insulated cables Mar 1939-Jan 1947