The science of wireless is but a few years old. We know about it little more than our schoolboy sons, and in many cases not so much; let us therefore be open-minded if we are still ignorant. Commercial invention trusts too far to mass thinking: an original mistake is very closely related to an accomplishment. THE IMPORTANCE OF SOUND IN WIRELESS A few lines of history are desirable here. I do not mean the history controlled by the fact that William the Conqueror made many important appointments in A.D. 1066 or that Stephen was particularly busy in A.D. 1100. I mean the history of wireless, for, although Radio Science is new, it has a history; all time is relative, and we ourselves are functions of that phenomenon. Only a few years ago the efforts of wireless experimenters were entirely directed to the converting of the extremely delicate wireless oscillation, still but little understood, into a mechanical movement, in order that the motion of electrons in a problematical aether (which may be nothing but a thought projection and which may exist in many different forms) might be altered into something readable by a man with a check waistcoat and a stock and share list in his hand. That particular use, and the information that one army is about to kill another could be transmitted to headquarters, naturally occurred to everyone as the first valuable applications of Radio. The many devices, the electro-magnetic receivers, tape machines, coherers, syphon recorders and the thousand and one electrical machines produced at the time for these purposes, have practically all gone. Even when to-day we want to send messages quickly, we record them upon a Dictaphone and rely almost entirely upon the sense of hearing. Sound, the regular oscillation, and noise, the irregular oscillation, of the air, are really the beginning and end of wireless as it is known to the public to-day. I would go further when thinking of the public. They do not want to sit with a telephone upon their heads, even if their ears may be improved thereby. They require to walk into a drawing-room, and having stood for a moment upon the mat, they must be able to cross the room, touch a button in a fretwork cabinet, and by the movement of a lever be able to place themselves in touch with any part of the world. Paris, Hong-Kong, London, all must be one to them if we are to get their money for our art. In other words, we are compelled to use what we now designate the “loud speaker.” We have got to project a sound into the room before we can sell our instruments, and therein lies one great difficulty.