I will tell you a fable to make the meaning clear. There once lived a race of blind men. Not one of them could see. They built houses and cities, railroads and steamships, but they did everything by touch and sound. When they met they touched each other and spoke, and each man knew his friend by the sound of his voice. One day a wise man among them said he believed there was something besides the sound of the voice with which they could make signals to each other. Another wise man thought upon this matter for some time and brought forth a proof that there is something called light, though no man could see it. Another, wiser and more practical, invented an eye which any man could carry about with him and see the light when he turned it in the direction from which the light was coming. Thereafter each man carried a light that flashed like the flashing of a firefly. Each man also carried an eye, and each could see his friend as well as hear the sound of his voice. The fable is true. The light which no man had seen we now call electric waves. The eye with which any one can perceive this light is the receiving instrument of the wireless telegraph. The strange light flashed out whenever an electric spark passed from an electrical machine, a Leyden jar, an induction-coil, or as lightning in the clouds, but for hundreds of years this light was unseen. The human eye could not see it, and no artificial eye that would catch electric waves had been invented. A man in England, James Clerk-Maxwell, first proved that there is such a light. Heinrich Hertz, a German, first made an eye that would catch the waves from the electric spark, and the man who first perfected an eye with which one could catch the electric waves at a great distance and improved the instruments for sending out such waves was Marconi.