“Of course you would disagree,” said Dick. “I’d like you less if you failed to. But honestly, now--you understand the principles on which the set works, you know how all the parts are put together, and you know how to operate it efficiently. On the whole, won’t you have to admit that this seven-tube set seemed far less complicated to you than did the first crystal set you ever made when you were new to the game?” “Well, yes, I guess I will,” admitted Stan. “As usual, I’m cornered. But just what are you driving at?” “I’ll come to that in a minute. Now, think of the thousands of people in this country who use radio receiving sets. They can tune them, after a fashion; they hear over long distances, mostly because of luck, and so they think themselves scientific research workers, and speak of their sets, which really do all the work, contemptuously--patronizingly. Yet those same sets, even if they have built them themselves (which is not usually the case) are really miracles to them, if they would only admit it.” “All done?” Stan inquired solicitously. “All done,” said Dick, wonderingly. “Right. Now listen to this and then unravel it, little logic. It’s gospel truth, and I’ve always wanted an explanation of it--but I never thought I’d meet anyone who would admit everything to be so simple as you do, so I’ve always kept it under my hat.” “I’m listening,” said Dick. “Before I came to college I had an amateur station in Los Angeles--big spark transmitter and all that. One winter I was listening in at about 1 o’clock in the morning. The stations up here around San Francisco that had been booming in an hour before had all seemed to shut down together, almost as if something had suddenly smothered them, if you get what I mean. The Los Angeles fellows, I suppose, thought that the northern fellows were having some sort of local interference, so they, too, shut down, one by one. 5ZA had been working his spark, down in New Mexico, but he seemed to fade out at about the same time the San Francisco stations did. “It was odd to hear the air so quiet. I tuned all up and down the scale, hoping for some eastern DX, although it was rather late, but there was not a station on the air. Thinking that perhaps my receiver was not working as it should, I started the rotary gap and drawled out a long CQ on full power, but none of the locals came back to ‘bawl me out’--I was alone on the air. It was eery; I felt as if I were the last inhabitant of a dead world, and the night outside--a sixty mile gale of ice-cold north wind had sprang up from nowhere--didn’t help to lessen the uncomfortable illusion. Suddenly, on about five hundred meters (I remember the setting of those dials as well as if I had them here in my hands now) I heard a low hum, and eight long dashes pealed out, one after the other, each of them one tone higher than the preceding one. _The octave in the key of C!_