"Tee-hee!" laughed Bud with fitting imitation of Hal's characteristic vocal merriment.

As for Tee-hee, that worthy individual preserved his dignity for the nonce.

"Well," laughed Mr. Perry; "You've hit the nail on the head, but I venture to say you can't explain why mathematics and imagination can put a mystery to rout."

Hal confessed he was unable to explain.

"It's too much highbrow for me," he said. "And I bet it's too much highbrow for Cub."

The latter said nothing. Evidently he was thinking hard. He leaned back in his camp chair and hoisted his feet upon the rail again.

"Well, let's quit the highbrow field and get down to business," suggested Mr. Perry. "If we're able to put this thing through along mathematical lines, I bet you boys will have enough imagination to tell me why mathematics and imagination can put any mystery on earth to rout."

"I'm goin' to get busy with the spark gap," Cub announced suddenly, as he sprang to his feet.

"You've got a big thing ahead of you, boys," announced the owner of the Catwhisker. "I venture to say there are some big surprises in store for you. For instance, you're likely to find the newspapers of the United States and Canada giving considerable s.p.a.ce to this affair."

"How are they going to get hold of it?" asked Bud.

"There's where you're short of imagination, my boy. How many amateurs do you suppose were listening in and got the messages between you and those two radio contestants?"

"I bet there were a hundred if there was one," declared Hal.

"And were they interested?"

"Were they?" exclaimed Cub. "Every last one of 'em was wild with curiosity."

"And did they talk about it to anybody?"

"They didn't talk about anything else," Bud opined.

"And didn't you suppose some of those amateurs know some newspaper reporters?"

"We fellows all know several reporters," said Cub, with an appreciative grin.

"All right," said Mr. Perry, significantly. "Now, all I have to say to you boys is, watch the headlines whenever you get near a news stand."

The three radio boys now repaired to the cabin, while the owner of the yacht busied himself about matters of nautical interest to him on deck.

"You've got to hand it to my father for one thing," Cub declared as he seated himself near the radio table and hoisted his feet thereupon. "He sure has some imagination."

"And some mathematics, too, the way he subtracts mist from mystery every time our brains get lost in a fog," Hal added, with a self-appreciative "tee-hee."

Cub and Bud also laughed in spite of Hal's excusable self-appreciation.

"Do you know, I don't feel nearly so mystified as I did before that talk with your father began," Bud announced.

"It's the mathematics and imagination getting their work in," Cub explained with a wink.

"It sounds funny, and yet, I can't help feeling there's something to it,"

Hal remarked.

"Well," said Cub, bringing his feet down from the table with enough noise to rivet a conclusion; "you may call it addition, or subtraction, or multiplication, or division, or algebra, or geometry, or trigonometry, or calculus--does that complete the list?--I'm going to make my imagination leap across the spark gap; so here goes."

He snapped the aerial switch into sending, began to "jiggle" the key alphabetically, and the spark leaped with successive spits across the gap.

"Cub's got his goat back," Hal remarked with a knowing look at Bud.

The latter grinned and nodded his concurrence.

CHAPTER VIII

Mathematics or Geography?

But the morning proved to be a poor time for communication by radio for two reasons. First, the atmosphere was warm, a poor condition for the transmission of ether waves, and after all, night time is the ideal season for such doings. Second, comparatively few amateurs were sitting in at this time of the day, although vacation had arrived and closed the schoolhouse doors.

Cub kept up his efforts for an hour, with virtually no success. Although he succeeded in communicating with half a dozen "hams", only one of them had listened-in to any of the messages that pa.s.sed between the Catwhisker boys and the two Canadian radio contestants, and he was able to throw no light on the "mystery". At last he gave it up for the time being, and joined the other Catwhiskerites on deck for a period of sightseeing enjoyment.

They cruised about among the islands most of the day, stopping here and there to inspect some apparently unclaimed scene of enchantment, or visiting various places exploited for gain by private interests as centers of entertainment and recreation. They circ.u.mnavigated Wellesly Island, making short stops at several points of interest and at about 4:30 p.m. tied up in a quiet shelter overhung by a low-limbed tamarack and cast their baited fishhooks into the water for a "brain-food" supper.

This was not more than half a mile from the tie-up where they pa.s.sed their first night in the Thousand Islands. The finny fellows bit greedily and in a short time they had enough black ba.s.s and pickerel to feed a party twice the size of theirs.

After supper all repaired to the cabin, and the boys donned phones, while Cub started a broadcasting campaign in search of information regarding the two Canadian wireless contestants, who seemed to have made a trio of monkeys out of the three radio motor-boat boys.

"I haven't much idea what kind of questions to ask or what kind of answers to expect," he said to his companions; "but here goes my best guess."

He had selected an intermission period in the atmosphere when the big broadcasting stations were quiet, and then gave the general call and sent out the following:

"I want help to identify and locate an amateur who figured in mysterious radio affair in last two days. He said his name was Raymond Flood, that he lived in Kingston, that his call was V A X, and that he was marooned on island in St. Lawrence River. Can anybody help me? Call A V L."

Immediately three amateurs, two in Canada and one in New York State, clamored for a hearing. Cub wrote down their calls and then took on the one in Kingston first.

"There is no such amateur in Kingston," the latter announced. "I know them all here. V A X is held by somebody in Port Hope. I listened-in to a lot of that stuff and called up three amateurs in Port Hope. I learned that A V L is Alvin Baker who is attending Edwards College."

"Why, he's my cousin!"

This exclamation from Hal created a real sensation in the cabin of the Catwhisker. Meanwhile Bud had been taking the message down longhand in order to preserve a record of the investigation, so that Mr. Perry, who read as the boys wrote, got the progress of events about as rapidly as did the three youthful experts. It is needless to say that he was as much astonished as were his boy companions.

But there was no time now for a discussion of family relationship. After a round of gasps and exclamations, they got down again to the business of their radio investigation.

That was about the extent of the information that the Kingston amateur was able to communicate to them, except that he had been an interested listener-in to much of the code conversations between the would-be rescuers and the two very strange radio contestants. He, however, promised to make further inquiries and to call them again if he learned anything that might be of interest to them.

"Well, dad, it looks as if you were right when you told us how to go about to solve this mystery," Cub remarked as he dash-and-dotted a "G N"

(good night) to the Kingston amateur.