Lord Kelvin’s contribution to submarine telegraphy

Professor William Thomson (later Lord Kelvin) solved the transmission properties of signals over long cables which specified design, instigated costs for conductivity, designed sensitive measuring and recording instruments and "curbing" systems which speeded transmission, and an improved brake for paying out cable. He also devised many navigational aids including a greatly improved compass and a depth sounder unaffected by ship\´s motion or ocean currents.