"I guess that will cook that fresh kid's goose," he said. "It's a mean thing to do, maybe, but I need the money, and I'm glad to get a chance to set him down a peg or two."

Thurman could hardly wait for the next night to come. During the day Jack had been having some more fun with the navy men, driving them almost wild. When Thurman finally got Washington, therefore, everything in the government's big wireless station was at fever heat. A high official of the navy sat by the operator, waiting for Thurman's promised call to come out of s.p.a.ce.

Men of the Secret Service were scattered about the room as well as department officials. The air was tense with expectancy. At last Thurman's message came.

His first question was about the reward.

"Tell him he will be liberally rewarded," ordered the naval official.

"Tell him to give us the information at once. That fellow has been playing with us all day, and we've been powerless to outwit the Universal Detector, or whatever device it is he uses. The man must be a wizard to have solved a problem that has baffled the keenest minds in the Navy Bureau."

"Reward is a.s.sured you," flashed back the naval operator. "Now give us your information. Time is precious."

But Thurman's answer proved disappointing to those in the room.

"Impossible to do so now. Inventor is on the high seas. Will wireless you later when he will return."

"Confound it," grumbled the naval official. "I thought we would have had our hands on the fellow before daylight. Now it seems we shall have to play a waiting game."

"If the man is on the high seas, it is not unlikely that he is the wireless man on one of the liners," put in Burns, a spare, grizzled man and Chief of the Secret Service.

"That's probable, Burns," rejoined the navy official.

"More than likely, I think," put in another member of the group, "but it's impossible to find out which one."

"Yes, we are at the mercy of our unknown informant," said Burns. "Why the deuce was he so mysterious about it?" He tugged at his gray mustache as a sudden thought struck him.

"Jove!" he exclaimed. "You don't think it's a put-up job to get money out of the government? Put up, I mean, by an agent of the inventor himself."

"I don't know, Burns," was the official's reply. "It's all mighty mysterious. I confess I can't hazard a guess as to the man's ident.i.ty.

We've looked up all the most prominent wireless sharps all over the country. I am satisfied this fellow is not one of their number."

"Some obscure fellow, I guess," said a Secret Service man.

"Well, he won't remain obscure long," remarked Burns, "if he has brains enough to turn the navy department topsy-turvy for forty-eight hours."

CHAPTER XXV.

A MYSTERY ON BOARD.

Two days later the monotony of the voyage, which was broken only by the radiograms which were posted daily concerning the race between the American and British liners--the _Columbia_ being in the lead--was rudely shattered by an incident in which Jack was destined to play an important part. Jack had been on a visit to Raynor during the young engineer's night watch in the engine-room. They had stayed chatting and talking over old times till Jack suddenly realized that it was long after midnight and time for him to be in his bunk.

Hastily saying good-night, he made his way through the deserted corridors of the great ship, which stretched empty and dimly lit before him. As he traversed them the young wireless man could not but think of the contrast to the busy life of the day when stewards swarmed and pa.s.sengers hurried to and fro. Now everything was silent and deserted, except for the still figures up on the bridge and below in the engine and fire rooms, guiding and powering the great vessel onward through the night at a twenty-four-knot clip.

The lad had just reached the end of one corridor, and was about to turn into another which led to a companionway, which would bring him to his own domain, when he stopped short, startled by the sound of a single sharp outcry. It came from the corridor he was about to turn into. Jack darted round the corner and almost instantly stumbled over the huddled body of a man lying outside one of the cabin doors.

A dark stain was under his head, and Jack saw at once that the man had been the victim of an attack. At almost the same moment, by the dim light, he recognized the unconscious form as being that of Joseph Rosenstein, a diamond merchant, so wealthy and famous that he had been pointed out to Jack by the purser as a celebrity.

"Queer fellow," the purser had said. "Won't put his jewels in the safe, although I understand he is carrying three magnificent diamonds with him. Likely to get into trouble if anyone on board knows about it."

"He's taking big chances," agreed Jack, and now here was the proof of his words lying at the boy's feet. Suddenly he recalled having received a message a few days before from New York for the injured man.

"Be very careful. F. is on board," it had read, and Jack interpreted this to be meant as a warning to the diamond merchant. But he did not devote much attention to it just then, except to rouse the sleepy stewards. Within a few minutes the captain and the doctor were on the scene.

"A nasty cut, done with a blackjack or a club," opined Dr. Browning, as he raised the man.

"Is it a mortal wound?" asked the captain. "This is a terrible thing to have happen on my ship."

"I think he'll pull through if no complications set in," said the doctor, and ordered the man removed to his cabin. Suddenly Jack recollected what the purser had said about the diamonds.

"I beg your pardon, sir," said he to the captain, "but I heard that this man carried about valuable diamonds with him. He was probably attacked for purposes of robbery."

"That's right," answered the captain, with a quick look of approval at Jack. "Browning, we'd better examine the contents of his pockets." They did so, but no traces of precious stones could be found.

"Whoever did this, robbed him," declared the captain, with a somber brow, "and the deuce of it is that, unless we can detect him, he will walk ash.o.r.e at Southampton or Cherbourg a free man."

The door of the stateroom opposite to which the injured man lay opened suddenly, and a little, wizen-faced man, wearing spectacles, looked out.

He appeared startled and shocked as he saw the limp form.

"Good gracious! This is terrible, terrible, captain," he sputtered.

"Is--is the man dead?"

"No, Professor Dusenberry, although that does not appear to be the fault of whoever attacked him," was the rejoinder.

"He was attacked, then, for purposes of robbery, do you think?"

"I suspect so."

"Oh, dear, this has so upset me that I shan't sleep the rest of the night," protested the little man, and withdrew into his stateroom.

The next day, naturally, the whole ship buzzed with the news of the night's happenings, and speculation ran rife as to who could have attacked the diamond merchant, who had recovered consciousness and was able to talk. He himself had not the slightest idea of his a.s.sailant. He had sat up till late in the smoking saloon, he said, and was coming along the corridor to his stateroom when he was struck down from behind.

A black leather wallet, containing three diamonds, which were destined to be sold to the scion of a European royal house, was missing from his pocket, and the loss nearly drove the unfortunate diamond man frantic.

He valued the stones at $150,000, so that perhaps his frenzy at losing them was not unnatural.

In the afternoon, Professor Dusenberry, dressed in a frock coat and top hat, although he was at sea and the weather was warm, came into the wireless room. He wanted to send a message, he said, a wireless to London. He was very cautious about inquiring the price and all the details before he sat down to write out his dispatch. When it was completed he handed it to Jack with his thin fingers, and asked that it be dispatched at once. Then he retreated, or rather faded, from the wireless room. Jack scanned the message with thoughtful eyes. It seemed an odd radiogram for a college professor, such as he had heard Prof.

Dusenberry was, to be sending. It read as follows:

"Meet me at three on the granite paving-stones. The weather is fine, but got no specimens. There is no suspicion as you have directed, but I'm afraid wrong."

F.

"Well, that's a fine muddle for somebody to make out when they get it,"

mused Jack, as he sent out a call for the Fowey Station.

"Must be some sort of a cipher the old fellow is using. He's a dry sort of old stick. Goodness! How scared he was when he saw that man lying outside his door. I thought he was going to faint or something."