The idea of communicating without any connecting wires is an old one. About the year 1842, Morse, of telegraph fame, succeeded in transmitting telegraphic signals across rivers and canals without a connecting wire. His method was to stretch along each bank of the river a wire equal in length to three times the breadth of the river. One of these wires was connected with the transmitter and with a battery, and the other with a receiver, both wires terminating in copper plates sunk in the water. In this case the water took the place of a connecting wire, and acted as the conducting medium. A few years later another investigator, a Scotchman named Lindsay, succeeded in telegraphing across the river Tay, at a point where it is over a mile and a half wide, by similar methods. Lindsay appears to have been the first to suggest the possibility of telegraphing across the Atlantic, and although at that time, 1845, the idea must have seemed a wild one, he had the firmest faith in its ultimate accomplishment. Amongst those who followed Lindsay’s experiments with keen interest was the late Sir William, then Mr. Preece, but it was not until 1882, twenty years after Lindsay’s death, that he commenced experiments on his own account. In March of that year the cable across the Solent failed, and Preece took the opportunity of trying to signal across without a connecting wire. He used two overhead wires, each terminating in large copper plates sunk in the sea, one stretching from Southampton to Southsea Pier, and the other from Ryde Pier to Sconce Point. The experiment was successful, audible Morse signals being received on each side. In this experiment, as in those of Morse and Lindsay, the water acted as the conducting medium; but a year or two later, Preece turned his attention to a different method of wireless communication, by means of induction. This method was based upon the fact that at the instant of starting and stopping a current in one wire, another current is induced in a second wire placed parallel to it, even when the two wires are a considerable distance apart. Many successful experiments in this induction telegraphy were made, one of the most striking being that between the Island of Mull and the mainland, in 1895. The cable between the island and the mainland had broken, and by means of induction perfect telegraphic communication was maintained during the time that the cable was being repaired. Although this system of wireless telegraphy is quite successful for short distances, it becomes impracticable when the distance is increased, because the length of each of the two parallel wires must be roughly equal to the distance between them. These experiments of Preece are of great interest, but we must leave them because they have little connexion with present-day wireless telegraphy, in which utterly different methods are used.