Early 20th century mains-powered electrotherapy apparatus

Made:
1901-1940 in London
maker:
Watson & Sons (Electro-Medical) Limited

Early 20th century mains-powered electrotherapy apparatus, for cauterisation and rheumatic treatment, by Watson and Sons Ltd., Sunic House, Parker Street, Kingsway, London, WC2, England, 1901-1940.