Boulitte electrocardiograph, manufactured by Boulitte, France, 1900-1930

This is an early form of electrocardiograph (ECG) machine. ECGs are graphical records of the activity in a person’s heart. These graphs are produced via an instrument called a galvanometer. In this example, the galvanometer is seen in the centre. Electrodes placed upon the body pick up on minute electrical impulses. These cause a string within the galvanometer to move. Movement is recorded photographically to make a tracing. Physicians examine these records for irregularities that may be a sign of disease. A plate camera can be seen in the rectangular box at the end. This electrocardiograph machine was made by French company Boulitte.