class="x-ebookmaker-pageno" title="17"/> working without pay. At times when trouble developed on two different wave lengths at once, he took a hand and helped out. For the most part he merely looked, listened and learned.

His pal he held in the greatest admiration. And who would not? Had he not, when this great big new thing, the radiophone, came leaping right into the world from nowhere, been able to take a hand from the very beginning and become at once a valuable servant of his beloved country? Had he not at times detected meddlers who were endangering the lives of men upon the high seas? Had he not at one time received the highest of commendations from the great chief of this secret service of the air?

To Joe there was something weirdly fascinating about the whole business. Here they were, two boys in the tower of the highest building in a great city. Five people knew of their presence. These five were high up in the radio secret service. No message sent out by them could ever be traced back to its source. They did not use the air. That would be dangerous, easily traced. They did not use the telephone alone. That, too, would be dangerous. But when a radiophone had been connected to the telephone wire and tuned to a certain wave length, then they talked and not even the person they talked with would ever know whence came the message. This was a necessary precaution for, from this very tower, dangerous bands of criminals, gangs of smugglers, and all other types of law-breakers would ultimately be brought to justice. And if these but knew of the presence of this boy in his tower room, some dark night that tower would be rocked by an exploding bomb and the boy in his room would be shaken to earth like a young mud-wasp in his nest.

"I'll tell you," said Curlie, as he rose to answer a tap on the door, "I believe that affair last night was some big thing; but what it was I can't even guess."

He opened the door to let in Coles Masters, his relief, then motioning to Joe he took his cap and left the room. Down the winding stairs which led to the elevator several stories lower down they made their way in silence, at last to enter a cage and be silently dropped to the ground hundreds of feet below.

"You see," Curlie began as he crossed his slim legs beside a small table in an all-night lunch room, buried somewhere in the deep recesses of this same skyscraper, "that fellow sent the message about the easterly breeze that blew west and I located the station at that hotel. This morning I went over to see how the place looked. It's a wonderful hotel, that one; palm garden in the middle of it, marble columns, fountain, painted sheet iron ceiling that'd make you dizzy to look at, and the finest dressed people you ever saw walking around everywhere.

"Well, I found my way to the sending room of the radiophone and right away the operator wanted to throw me out; said I was a fresh kid and all that. But when I showed him my papers, he calmed down a lot and showed me everything he had.

"I saw right away it wasn't his equipment that had sent that message—that'd be like sending a Big Bertha bomb into Paris with a twenty-two caliber rifle. He just naturally didn't have the power, that's all. So I didn't tell him anything about it; just walked out and went around back to where I could see the way his wires ran from the sending room to the antenna.

"I hadn't any more than got there and had one look-up when along strolls a man who wants to know what I'm looking at. I saw right away that he wasn't a hotel employee for he didn't wear either a bandmaster's uniform nor a cutaway coat, so I just smiled and said:

"Got a girl friend up there on the sixteenth floor. She's leaving this morning and arranged to drop her trunk down to me so's not to have to tip the porter.

"Well, sir, I hadn't more than said that than a girl did pop her head out of a sixteenth floor window and stare straight down at me.

"The fellow actually dodged. Guess he thought the trunk was due any minute.

"Funny part of it was the girl actually seemed interested in me, just as if she had met me somewhere before. Of course she was too high up for me to tell what she was like, but it made me mighty curious. I counted the windows to right and left so I could find that room if I wanted to. The window was only the third to the right from where the lead wire to the antenna went up.

"Well, then, that fellow—"

"Mr. Carson?" a voice interrupted Curlie. "Anyone here by the name of Carson?" It came from the desk-clerk of the eating place.

"That's me," exclaimed Curlie, jumping up.

"Telephone."

"All right. Be back in a minute, Joe." Curlie was away to answer the call.

"'Lo. That you, Curlie?" came through the receiver. "This is Coles Masters. Got a bad case—extra bad. Can't understand it. Fellow's sending 600 meter waves, with enough power to cross the Atlantic."

"Six hundred!" exclaimed Curlie in a tense whisper. "Why, that's what they use for S.O.S. at sea! It's criminal. Endangers every ship in distress. Five years in prison for it. Get him, can't you?"

"Can't. That's the trouble. Every time I think I've got him spotted he seems to move."

"To move!"

"Yes, sir."

"That's queer! I'll be up right away."

"Come on," exclaimed Curlie, grabbing his hat and dragging Joe to his feet. "It's a big one. Moves, he says. Sends 600; big power. Bet it's that same hotel fellow. Gee whiz! Supposing it turned out to be that sixteenth story girl and she caught me spying on her. I tell you it's something big!"

Impatient at the slowness of the up-shooting elevator, Curlie at last leaped out before the iron door at the top was half open, then two steps at a time sprang up a flight of stairs. Out of breath, he arrived at the final landing, sprang through the door to the secret tower room, then seizing his headpiece, sank into a chair.

By a single move of the hand, Coles Masters indicated the radio-compass he had been listening in on.

"That's where he was, last time he spoke," he grumbled, "but no telling where he'll be next. He's been dodging all over that stretch of country."

Curlie's fingers moved rapidly. He adjusted the coil of a radio-compass here, another there and still another here. He twisted the knob of each to the 600 mark, then, twisting the tuning knobs, lined them all up to receive on the same wave length. The winding of each was set at a slightly different angle from any other.

"That about covers him," he mumbled. "Get the distance?"

"Near as I could make out," said Coles Masters, "it was from ten to fifteen miles. He moves toward us, then away at times, just as he does to right and left."

"Hm," sighed Curlie, resting his chin on his hands. "That's a new dodge, this moving business. Complicates things, that does."

For a time he sat in a brown study. At last he spoke again, this time quite as much to himself as to the other:

"Folks don't move unless they have a way to move. That fellow has some means of locomotion. Anyway," he sighed, "it's not our friend of the big hotel unless—unless he or she or whoever it is has taken to locomotion, and that's not likely. Not the same side of the city. Out near the forest preserve."

"Yes, or a little beyond," said Coles.

"What do you think," asked Curlie suddenly, "has he got an automobile or an airplane?"

"Can't tell," said Coles thoughtfully.