Resistance coils inside perforated case. Stud switch; terminals for +, 240, 210, 190. 2-pin lamp socket; tumber switch. Rheostat for Arc Lamp
Rheostat by Birch, serial No. 19312/49, resistance 10 ohms, rating 5A (one terminal screw missing) Rheostat by Birch 1950-1980
Varley's carbonised cloth rheostat by Townson & Mercer, consisting of a number of cloth discs which can be compressed by a screw Varley's carbonised cloth rheostat by Townson & Mercer 1890-1939