Cables under the Sea

Soon after telegraph cables came into use in the 1840’s attempts were made to lay them across rivers and between islands and main lands. Most didn’t work. In 1850 the first cable was laid across the English Channel. It had to resist attack by salt water, ocean currents and water pressure, so had thick, water – resistant, steel cover. Inside were copper wires that carried the power and signal. Technical improvements and the demand for faster communications led to cables being laid over ever greater distances. Several attempts to lay them across the Atlantic failed when the cables snapped, but one was completed in 1858. To mark the occasion, Queen Victoria sent a telegraphic message to President Buchanan in the USA. It took almost 18 hours. Attempts were made to increase the pace by raising the voltage, but this burned out the cable. In 1865 the world’s largest ship at the time, the Great Eastern, laid the first continuous cable across the Atlantic.