The man began to lay submarine cables since the mid-nineteenth century in order to communicate signals continents through telegraph, telephone and even television images. These cables are a set of filaments coated conductors by an insulating layer and located on the ocean floor. The first undersea cables, through which telegraph signals were sent, was laid in 1850 between England and France. In 1866 he began operating the first transatlantic cable. In 1956, thanks to the development of telephone towers, was placed between Scotland and Newfoundland, at 3660 meters deep, the first cable capable of conducting voice communications.
The latest cables transistorized repeaters have and provide more voice circuits. Some of them are capable of leading television images.
If started to settle after the Atlantic, there are also submarine cables in the Pacific, such as connecting California Hawaii and linking these islands to Japan.