A numerical model for submarine telegraph communication

Transmission Line Matrix (TLM) is a modern numerical method which is particularly suited to treating electromagnetic problems This paper describes the application of TLM to the propagation of telegraph signals in ocean cables. It is shown that the non-ideal properties of the cable, the transmitter and the receiver were significant factors in the ability to receive signals at a time when people had no concept of the importance of impedance matching. The paper concludes with a demonstration of the benefits of a cable whose electrical parameters comply with the Heaviside distortionless condition.