“The moral is that if you must predict it is better to do so in favor of rather than against a proposition unless you’re betting on a horse. My opinion is that signaling to Mars will not be done by long electric waves set up by electric sparks. Some years ago Tesla, the electrician, was reported to have received signals from Mars by long electric waves, that is wireless waves, while Pickering the astronomer got up a plan to reflect signals to the red planet by short electric, that is light waves. All he needed to do it with was ten million dollars’ worth of mirrors and by forming these into a gigantic reflector he opined he could concentrate the light of the sun into a beam and throw it on the surface of Mars. “And this puts me in mind of Tesla’s scheme to transmit power wirelessly. To transmit power to run machinery and to control power at a distance by wireless are two entirely different things. Since wireless waves tend to radiate in all directions parallel with the surface of the earth from an aerial, it is a very difficult matter to transmit enough energy wirelessly in any one direction to have a sufficient quantity left after it has passed through even a short distance to do useful work such as running a motor. “As early as 1905 Tesla took out patents for a system of wireless transmission of power in which he proposed to use the free ether of space instead of the ether in and around a wire to guide and carry it. He built a great tower at Wardencliff, Long Island, New York, for the purpose of radiating power but nothing came of the experiments he made and after some years the tower was torn down.” “You don’t believe then that it will ever be possible to transmit energy for power purposes by wireless?” “On the contrary, I believe it is possible but other discoveries must be made before it can be done successfully and this is also true of many other things which have been and are still looked upon as physical impossibilities. As to controlling apparatus at a distance by wireless that is, of course, just as easy as sending a signal, in fact it’s the same thing. “Tesla was the first to control the movements of a boat at a distance by wireless and after him came many others. Even submarines have been so equipped and controlled but since the surface of the sea reflects most of the energy of the waves and absorbs the rest of it the boat must have its aerial above the surface at all times or the waves will not reach it. “Attempts to control airships by wireless have been made time without number but to no useful purpose for no effective distance can be had between an airship and the sending station. Even sending wireless messages from airplanes as you said yesterday is only done over a very short distance and these limits are quickly reached because there is no way of grounding it.” “How do you think the distance could be increased?” Jack wanted to know.