A wooden case with a handle and a brass plaque inscribed: "Dr. W.J.Armstrong." Case contains portable electrocardiograph (model 51, serial 9758). Unlike earlier battery powered photographic models, Viso Cardiette is an AC powered direct-writing instrument

By Sanborn Company

Made for Bernard Fuchs MD. Case contains portable electrocardiograph. Unlike earlier battery powered photographic models, this is an AC powered instrument.

By Cambridge Instrument Co., Inc.

Circa 1935-1947