“It came about in this way. In 1896 the _International Wireless Telegraph Convention_ was held in Berlin. Germany’s wireless men, from her greatest scientists down to her lowly operators hated anything that had to do with or was used by Marconi, so instead of _C Q D_, they suggested that the letters _S O S_ be used. Unlike _C Q D_, the letters _S O S_ have no especial meaning in themselves but they are easy to send and to read and make, as a matter of fact, a good distress call. “While _S O S_, was probably sent out many times by various operators from that time on it did not become famous until the s. s. _Kentucky_ went down off the Diamond Shoals. Her operator did as many an operator had done before him and has done since, that is, he kept sending the _S O S_ call. Her engine room was rapidly filling with water but before her dynamos were submerged and put out of commission the operator on the _Alamo_ of the _Mallory Line_, ninety miles away, heard the call. The _Alamo_ reached the sinking ship just in time to save her passengers and crew before she went down.” “Do you think it is possible to send a wireless message around the world?” “Not without relaying it. You remember back there in 1909 when all the small fry who were following in Marconi’s footsteps were trying to do something more wonderful than the great inventor? One of them made the statement that he had sent out a train of electric waves from his high power station which traveled completely round the world and in a small fraction of a second he received the signals on the same aerial; and he was backed up in it by a college professor, too.” “I agree with you that college professors may sometimes be wrong, indeed they are nearly always so,” I assured him. “Now any kid operator knows,” continued Jack, “that electric waves are radiated to every point of the compass around an aerial and hence even if the waves sent out by it had enough power to go around the world they would meet on the opposite side of the earth and neutralize each other. “What do you think about signaling from the earth to Mars, Mr. Collins?” “Not very much. It is never safe to predict, especially to make a negative prediction, by which I mean to say that a thing can’t be done. Simon Newcomb, the great astronomer and mathematician, proved by figures and the known laws of nature, to his own satisfaction and a good many others, that it was a physical impossibility to build a man-carrying airplane. “Langley who was just as big a figure in the world of science believed that the thing could be done, built model after model that flew but when he built his big machine to be piloted by a man it fell before it got fairly into the air. Yet the same year that he failed, the Wright Brothers, a couple of bicycle mechanics, put a gasoline engine in a glider and flew. Since then bombing airplanes have been built that will carry a ton or more.