Electrical switch, one of four, for physiological use, by C.F. Palmer, London, 1920-1940 Electrical switch 1920-1940
Electrical switch, one of four, for physiological use, by C.F. Palmer, London, 1920-1940 Electrical switch 1920-1940
Electrical switch, one of four, for physiological use, by C.F. Palmer, London, 1920-1940 Electrical switch 1920-1940
Electrical switch, one of four, for physiological use, by C.F. Palmer, London, 1920-1940 Electrical switch 1920-1940