I have accused man of adopting very wasteful processes, so I had better explain the matter. In the preceding description of what is occurring in an electric glow lamp, I have spoken only of those æther waves which constitute light. But there are myriads of electrons in the carbon of the glow lamp that never attain the requisite speed to produce those waves; they revolve around their atoms at too slow a rate. They certainly disturb the æther, but the crests of the waves are so far apart that they do not affect the eyes of man. The business of these waves is to set up heat in the bodies upon which they fall. You may be surprised to know that in this contrivance of man, called an electric glow lamp, and, indeed, in all his other artificial light-producers, he causes far more electrons to produce radiant heat than the desired light waves. A most wasteful process! Man has a long way to travel yet before he succeeds in producing artificial light by a reasonable process. Indeed I doubt if any of you can realise, as we do, how exceedingly stupid the existing methods are. Think for a moment of the glow-worm, in which we electrons produce light without setting up any wasteful heat waves. There is a strong contrast between this peaceful plan and that of the excited carbon atoms. When will man succeed in discovering this secret of ours? CHAPTER XV WE SEND MESSAGES FROM THE STARS _THE SCRIBE'S NOTE ON CHAPTER FIFTEEN_ It is remarkable that man has been able to discover what the distant stars are made of. Our knowledge concerning the chemistry of the stars has been obtained by means of the spectroscope, in which a beam of light from the star is passed through a glass prism. The result is the well-known image of the coloured spectrum, in which certain well-defined lines appear, according to the distant elements originating the æther waves. The electron explains the whole subject from its own point of view. CHAPTER XV WE SEND MESSAGES FROM THE STARS It is only within recent times that man has observed that we send messages from the distant stars to this planet. But there is nothing new to us in this proceeding; we have been busy sending these messages ever since the solar system was formed. Through all those ages we have kept on sending these messages, knowing that in time man must come to take notice of them.