Portable electrocardiograph machine, all-mains model, cover missing, on trolley with case containing 8 film drums, No.C431477, by Cambridge Instrument Co. Ltd., 1946 Portable electrocardiograph machine 1946
Portable electrocardiograph machine, all-mains model, with battery in case and accessories, No. C288766, by Cambridge Instrument Co. Ltd., 1940 Portable electrocardiograph machine 1940