ABSTRACT
In order to trace the history of underground cable systems, it is necessary to examine the early days of the telegraph [1-1, 1-2]. The telegraph was the first device utilizing electrical energy to become of any commercial importance and its development necessarily required the use of underground construction. Experimentation with underground cables accordingly was carried on contemporaneously with the development of the apparatus for sending and receiving signals. Underground construction was planned for most of the earliest commercial lines. A number of these early installations are of considerable interest as marking steps in the development of the extensive underground power systems in operation around the world.
