The telautograph transmists electrical impulses recorded by potentiometers at the sending station to servomechanismas attached to a pen at the receiving station. This machine is the precursor to the modern fax machine. It is the first device to transmit drawings to a stationary sheet of paper.

Elisha Gray invented and patented the telautograph in 1888. It was publicly exhibited in 1893. The telautograph became popular for sending signatures over long distances and was often used by banks and doctors.