"Huh, I don't think the idea's worth a cent," sniffed Thurman contemptuously, when Jack had finished.

"I guess that's where you and I differ," said Jack, controlling his temper with some difficulty, for the sneer in Thurman's voice had been marked. "I'm going to make it a success, and then we shall see."

He left the wireless room, and the instant he was gone Thurman, with a crafty look on his flabby face, eagerly began examining the detector. As he was doing so Jack, who had forgotten his cap, suddenly reentered the wireless room. Thurman had been so intent on his scrutiny of the detector that he did not hear him.

"You appear to be taking great interest in that useless invention," said Jack in a quiet voice.

Thurman started and spun round. His face turned red and he had an almost guilty look.

"I didn't think you were coming creeping back like that," he exclaimed, "a fellow would almost think you were spying on him."

"Have you any reason to fear being spied upon?" asked Jack.

"Me? No, not the least. That's a funny question."

"I want to tell you, Thurman, that my invention is not yet completed and therefore, of course, is not patented. I was pretty free with you in describing it, and I shall trust to your honor not to talk about it to anyone."

"Certainly not," bl.u.s.tered Thurman. "I'm not that sort of a chap."

But, after Jack had gone out, he resumed his study of the detector a second time, desisting every time he heard a step outside.

"So it's not patented, eh?" he muttered to himself. "That will help.

It's an idea there that ought to be worth a pot of money."

CHAPTER XXIII.

JACK'S BIG SECRET.

The next day Jack found an opportunity to sandwich in some work on his invention between his regular work. The thing fascinated him, and he tried and tested it in a hundred different combinations. Suddenly, just after he had altered two important units of the device, a new note came to his ears through the "watch-case" receivers that were clamped to his head.

"It's code--somebody sending code!" exclaimed Jack, and then the next instant, "it's some ship of the navy! Hurrah! The detector is working, for they use different wave lengths from the commercial workers, and, if it hadn't been for the Universal Detector, I'd never have been able to listen in at their little talk-fest."

He waited till the code message, a long one from Washington to the _Idaho_, of the North Atlantic fleet at Guantanamo, Cuba, was finished, and then he could not refrain from "b.u.t.ting in."

"h.e.l.lo, navy," he chattered with the wireless key, "that was a nice little message you had. How's the weather up your way?"

"Who is this?" demanded the navy wireless in imperious tones.

"Oh, just a fellow who was listening," responded Jack.

"b.u.t.ting in, you mean. But say, how did you ever get on to our sending?

We were using eccentric wave-lengths to keep our talk a secret."

"I'll have to keep how I caught your talk a secret, too, for the present, old man."

"Great Scott! It isn't possible that you've solved the problem of a universal detector. Why, that's a thing the navy sharps have been working on for years."

"I can't say how I caught your message," shot back Jack's radio through s.p.a.ce.

"You'll have to tell if the government gets after you," was the reply.

"Uncle Sam isn't going to have a fellow running round loose with anything like that."

"What do you mean?"

"That you will be forbidden to use it."

"Is that so?"

"Yes, that's so. I'm going to make out a report for my superiors about it right now. You're pretty fresh."

"Put that in the report, too," chuckled the _Columbia's_ wireless disdainfully.

"You'll find it's no joke to monkey with the government," snapped back the naval man.

Jack didn't answer. A message from the _Taurus_, of the Bull Line, was coming in. She had sighted an iceberg, something very unusual at that time of year. Jack hurried the message, which gave lat.i.tude and longitude of the menace, to Captain Turner.

"Well, that won't bother us," said that dignitary. "We're far to the south of that. Those Bull fellows run to Quebec. Send a radio to Captain Spencer, of the _Taurus_, thanking him for his information."

The great man, the captain of a liner, who has literally more power than a king, lit a cigar, and bent his head once more over the problem in navigation he was wrestling with. Jack saluted and hurried back to his quarters.

He was highly elated over the success of his Universal Detector. The threats of the government man did not alarm him, for he did not propose to place his invention on the general market, but to sell it outright to the government, whose secret it would then remain.

He resolved to test it again. A moment after he had put the receivers to his ears, a broad grin came over his face. The air was literally vibrant with the calls of the navy men, flinging their high-powered currents through s.p.a.ce.

"... he's a cheeky beggar, whoever he is, but he's got the goods," was the first he heard.

"Hum, that's Mr. Washington," thought Jack. Then, from some other point came another message.

"Great Scott! Uncle Sam won't let him get away with anything like that."

"I should say not. The Secret Service department is already at work trying to find out who the d.i.c.kens he is."

"That will be a sweet job," came the naval station at Point Judith.

"Talk about a needle in a haystack," sputtered the U. S. S. _Alabama_.

"Not a patch on it," agreed the great dreadnought _Florida_.

Then came Washington again.

"I'll tell you it's stirred up a fuss here," he said. "I wonder who it can be."

"Maybe that Italian fellow who invented the sliding sounder," suggested the _Florida_.

"Or Pederson, out in Chicago," came from a land station. All the navy men appeared to be joining in the confab.