RADIO BOYS IN THE THOUSAND ISLANDS

or, The Yankee-Canadian Wireless Trail

by

J. W. DUFFIELD

Author of

RADIO BOYS IN THE SECRET SERVICE; or, Cast Away on an Iceberg. RADIO BOYS IN THE FLYING SERVICE; or, Held For Ransom by Mexican Bandits. RADIO BOYS IN THE ROCKIES; or, The Mystery of the Lost Valley.

1922



CONTENTS

Chapter

I Vacation Plans

II Tragedy or Joke

III Talking it over

IV The Catwhisker

V A Baffling Situation

VI A Mystery and Cub's "Goat"

VII Returning Cub's "Goat"

VIII Mathematics or Geography?

IX The Radio Diagram

X The Island-Surrounded Island

XI The Deserted Camp

XII Hal's Discovery

XIII "Robinson Crusoe's" Diary

XIV More Light and More Mystery

XV The Hook-up on Shore

XVI Running down a Radio Fake

XVII Bud's Discovery

XVIII Unwelcome Visitors

XIX "S.O.S." from Friday Island

XX Four Prisoners

XXI The Hostage

XXII The "Crusoe Mystery" Deepens

XXIII "Sweating" the Prisoner

XXIV "Something Happens"

XXV Bud Shoots

XXVI The Slingshot Victim

XXVII Chased out

XXVIII A Radio Eavesdropper

XXIX The End of the "Mystery"

XXX The Result of a Radio Hazing



CHAPTER I

Vacation Plans

"Now, fellows, what are we goin' to do this vacation?" demanded Cub Perry as he leaned back in his upholstered reed rocker and hoisted his size 8 shoes onto the foot of his bedstead. "School's all over, we've all passed our exams, and now we've got a long vacation before us with nothing to do. It's up to yo-uns to map out a program."

"Why can't you help map it out?" asked Bud Taylor with something of a challenge in his voice. "You always have the last word?"

"Cub's the dictator of our outfit, and we do the work, that's why," declared Hal Stone. "We always have to listen to him, you know that, Bud. So what's the use o' kickin'?"

"Oh, I'm not kickin'," Bud replied. "It's no use. Cub 'u'd drown us out with his voice if we hollered. You know you made 'im admit once that noise was the only thing that 'u'd convince him."

"You c'n change that now and call it static instead of noise since we've all become radio experts," smirked Cub with characteristic superiority.

"Ha, ha," laughed Bud.

"Tee-hee," tittered Hal.

By the way, it was from this peculiar manner of laugh, that Hal got his nickname, Tee-hee. Cub's given name was Robert, shortened sometimes to Bob and Bud's was Roy. Cub and Bud were always known by their nicknames, but Hal was addressed as Tee-hee only on fitting or intermittent occasions.

The three boys were seated in Cub's room at the Perry home, one of the largest and most interesting samples of domestic architecture in the City of Oswego, on the shore of Lake Ontario. Cub was a rich man's son, but he was constitutionally, almost grotesquely, democratic. There was nothing that would make him angrier, to all appearance at least, than open reference in conversation to the wealth of his father. For such offense he was ever ready to "take off the head" of the offender. However, once in a while one of the bolder of his friends would beard the lion in his den more or less successfully. But it was necessary for such venturesome person to be ever in command of ready wit in order to emerge with a whole skin, figuratively speaking, and Bud and Tee-hee were the real leaders of this victorious few. That was the reason why they were chums of Cub.

The fact of the matter, to be perfectly frank, was that Cub was a good deal of an actor. Whether he was conscious of this fact we will not venture to say. He is the only one who knows, and we have never broached the subject to him. The average person on first making his acquaintance doubtless would set him down as a very domineering youth; some might even call him a bully, but they would change their minds eventually if the acquaintance continued. Perhaps the best way one could judge Cub, without being Cub himself, would be to characterize him as being fond of playing the bully just for fun. Indeed, it is quite probable that Cub carried a perpetual laugh in his sleeve.

This dominant youth was tall and lanky. He was only 17 years old, but as big as a man, so far as altitude and the size of his feet were concerned. He lacked one inch of being six feet tall, and he wore size 8 shoes. The hope for his proportion was expansion, and judging from the hereditary history of his paternal ancestry, there was good prospect for him in this regard. His father was a large man and well built.

To complete the description of Cub, he was a youth of very wise countenance. He liked to read "highbrow stuff" and reflect and inflict it on such victims as were unable to counter his domination.

Bud was a short, quick, snappy, bold fellow, "built on the ground". It is possible that he might have upset Cub in a surprise wrestle, but nobody ever dared to "mix" with Cub in such manner; the lanky fellow seemed to be able to out-countenance any suggestion of physical hostility. The glower of his face seemed to spell subjection for all the boy world about him.

But Bud would blurt out something now and then that seemed to startle Cub into a mood of reflection, and whenever Cub reflected his dominance wavered. Tee-hee was able to accomplish the same effect without a "blurt". Tee-hee was sly, "as sly as they make 'em", but it was a kind of slyness that commands respect. It even gave an air of respectability to his laugh, for, ordinarily, a "tee-hee" sounds silly. But Hal's "tee-hee" was constitutional with him, and his sly shrewdness gave it real dignity.

Cub was usually the dominating factor in all the boy arguments of their "bunch", which varied in numbers from ten to twenty, according to the motive of interest that drew them together. He seldom started an argument, unless his disposition to "bawl" somebody out for uttering a, to him, foolish opinion, he regarded as a starter. He seldom spoke first, but usually last. One day he "bawled" Tee-hee for the latter's "silly laugh", telling him that he would never be a man unless he learned to "laugh from his lungs".

"You seem to like a lot of noise," Hal observed.

"Yes, it's the only thing that convinces me," Cub shot back rashly.

He realized his rashness, but it was too late. Tee-hee "got" him.

"I understand you now," the sly youth announced. "Whenever we have a dispute, the only way for me to win is to make a bigger noise than you do."

But Cub was not slow, and he evened matters up by roaring:

"You can't do it; you ain't got the lungs."

However, there was a serious side to this trio of radio boys. They were not known chiefly for their frivolity, which probably would have characterized them if they had got into any bad scrapes. Their deportment was really above reproach, so that their parents reposed a good deal of confidence in them and allowed them to do pretty much as they wished in the matter of their recreation and sports. On the occasion with which the narrative opens we find them very serious minded over a very important problem, although it seemed well nigh impossible for them, even under such circumstances, to bar severely all manner of gaieties.

"I don't see where there's anything new for us to do this summer," said Bud after the merriment over the "static repartee" with Cub had subsided. "We c'n go camping or fishin', or we c'n stay at home and listen in."

"Oh, you haven't got any invention in that head o' yours, Bud," declared Cub with tone of disgust. "Tee-hee, take your turn and see if you can't hand us somethin'."

"Aw, why don't you furnish some brains for us, Cub," Bud objected with spirit. "I never knew you to yet. You just razz us till we turn up the thing all of us wants, and then you act as if you'd done all the work."

"Well, what do I pay you for?" Cub demanded, with an air of final judgment.

Of course, Cub did not pay them anything; that was just a little evidence of his exasperating domination. Bud saw, as usual, that there was no use of trying to carry his protest further, so he gave way to Hal, who looked as if eager to take his turn.

"I tell you what let's do," proposed the latter. "Let's go campin' and take one of our radio sets with us."

Cub leaped to his feet enthusiastically, bringing his feet down on the floor with a force that seemed to jar the whole house. Fortunately there was a substantial rug between his descending number 8's and the floor.

"That's what I call brains, Tee-hee," he declared, reaching over and planting a hearty slap on the author of this ingenuity. "You deserve a bonus. The scheme is hereby adopted."

"Without consulting me?" demanded Bud with very good simulation of hurt dignity.

"Absolutely, Bud, you fell asleep and let Tee-hee get ahead of you."

"And meanwhile, what did you do?" Bud inquired pointedly.

"I sat in judgment over your suggestions," Cub replied readily. "You fellows needed somebody to decide what your suggestions were worth. That's my function—get me?—my function."

"Well, I was goin' to vote for Tee-hee's idea," said Bud with slight tone of resentment. "You might 'ave let me get my vote in."

"It wasn't needed, it wasn't needed," Cub ruled. "Two's a majority of three."

"I'm going to vote for it anyway. I think his idea is a dandy."

"Your vote is accepted and recorded as surplus noise."

"Static, you mean," Bud suggested with modest sarcasm.

"To be up to date, yes."

"Tee-hee," laughed Tee-hee.



CHAPTER II

Tragedy or Joke?

The three boys discussed vacation plans along the line suggested by Hal for half an hour, and then Cub said:

"We can't get any further on this subject to-night. It's nearly 8 o'clock; Let's go in the radio room and listen to some opera music for a while."

He led the way into an adjoining apartment, a veritable radio laboratory. Two years before, as a wireless amateur, Cub had built for himself in this room an elaborate sending and receiving set, and he proved to be one of the first, boy though he was, to appreciate the outlook for the radiophone, even before "the craze" had gripped the country. He soon had his father almost as much interested in the subject as himself, so that the question of financing his latest radio ambition was no serious obstacle. An early result of this active interest on his part was the addition of a receiving amplification with which he could listen in to messages from major-power stations in the remotest parts of the country. Indeed, under favorable conditions, he had picked up messages from as far distant points as Edinburgh, Scotland, and Australia.

Cub sat down at the table and tuned to 360 meters. The other boys seated themselves comfortably and waited with a kind of luxurious contentment for the beginning of the program, which came in a few minutes. They "sat through" the entire Westinghouse program and then Cub began to "tune up and down" to find out what else was going on in the air. The room for several minutes was resonant with a succession of squeaks, squawks, whines, growls, dots-and-dashes, whistles, and musical notes. Suddenly he gave a start that aroused the curiosity of his friends and made them more attentive to his actions.

"Did you get that?" he shouted.

"No," replied Bud and Hal, in chorus, springing forward.

Cub was tuning excitedly back and forth about a certain, or uncertain, wave length, which he had lost.

"Put on your 'phones," he said, putting on his own. "You may not get it through the horn. I'm sure I got an SOS, very faint. I'm going to try to get it again."

Bud and Hal did as directed and listened with quite as much eagerness as that which was evident in Cub's manner. Several minutes elapsed before the search was rewarded. Then at last, in fairly distinct, although faint, vibrations came the distress signal again. All three heard it, and this time Cub caught the wave "on the knob" and did not let it go.

The operator sending the distress signal was evidently pleading desperately for attention, which nobody, it seemed, was willing to give to him. Several times he repeated his SOS, following each repetition with his own private call and wave length. Then he broadcast the following message in explanation of his appeal for help:

"I am marooned on island in Lake of Thousand Isles. I landed here from a motor boat with wireless outfit. Lake thieves stole my boat and left me here with outfit and little food. Will starve in few days if I don't get help. My call is V A X."

"Cracky!" exclaimed Bud excitedly. "Isn't that a thriller! He's an amateur and in trouble. We're in honor bound to help him."

"How?" demanded Cub derisively. "What can we do here nearly two hundred miles away from him?"

"We might get word to some police or lake patrol that'll go and take him off," Hal suggested.

"He's a Canadian," objected Cub. "Didn't you get his Canadian call? We'd have the time of our life getting a Government station to pay any attention to us hams. But listen, somebody's calling him."

All three listened-in eagerly, expectantly, wonderingly. Apparently this fellow also was a Canadian amateur, although he failed to identify himself.

"Oh, come off, you can't get by with that Robinson Crusoe stuff in this twentieth century," he "jeered" with all the pep he could put into his spark. "Some joke you're trying to play. What kind of publicity stunt is this, anyway?"

"No publicity," was "Crusoe's" reply. "I'll starve if I don't get help. You're doing your best to kill me. Keep out, I won't talk to you any more."

"I will not keep out," declared the other. "You're an imposter. I'm protecting the public."

"Whew!" ejaculated Cub, wiping his brow and snapping over the aerial switch. "I'm going to find out something about this."

A moment later his right hand was working the sending key with the speed and skill of an expert, while blue flames leaped over the gap with spiteful alphabetic spits. Hal and Bud watched him eagerly, and, with a skill indicating long and studied practice, read the message their lanky friend shot through the ether.

First he tuned for a few moments and then sent the call which had accompanied the first Canadian's "SOS". Then he threw back the switch and received a speedy answer. There seemed to be an almost spasmodic eagerness in the manner in which he sent his acknowledgment.

"I heard your call for help," was Cub's next cast. "Who was that fellow that snapped you up so sassy?"

"I don't know," answered the professed castaway. "I've been trying to get help for more than a day, and he always breaks in and queers my call. He makes everybody think I'm putting up a prank."

"Where is your island?" asked Cub.

"Somewhere in the Thousand Islands. That's the best I can locate it. I've never been here before. Where are you?"

"At Oswego, New York."

"What's your call?"

"A V L."

"Can you do anything for me?"

"I don't know what I can do unless I try to interest somebody near you by wireless. I'll send out a broadcast in any manner you may suggest. But you can do that just as well as I."

"I have done it over and over, but it does not do any good," said "Crusoe". "That evil genius of mine always manages to queer me. Finally I got so desperate that I sent out an SOS."

"And committed a radio crime," broke in the alleged evil genius. "Don't you know the rules governing that distress signal?"

"There he is again," "Crusoe" dot-and-dashed.

"Who are you?" demanded Cub.

"I am Canadian amateur," was the reply. "That fellow who sent the distress signal is a Canadian college student trying to put over a college prank. I am on his trail to prevent him. We have a wager up; if he induces anybody to go to his rescue, I lose."

"That is not true," interposed the sender of the SOS.

"What is your call?" Cub inquired.

"Yes, give it to him, and tell him what college I am from," proposed the "fellow on the island".

"One of the conditions of our wager is that I must not reveal my identity," returned the anonymous amateur. "He's bound by like terms. He does not dare give you his name and address."

"That fellow is insane or a villain," declared "Crusoe". "I do not know who he is, but if I starve to death, he'll be a wanton murderer. My name is Raymond Flood. I am not a college student. I am a high school student at Kingston."

"Is his name Raymond Flood?" was Cub's next query intended for the anonymous amateur.

"No," was the latter's reply.

"What is it?"

"Under terms of our wager, I must not reveal his name and he must not reveal mine."

"Whew!" exclaimed Cub, addressing his two friends, who removed the phones from their ears, the better to hear him. "Can you beat that?"

"We sure have hit a sensation of some sort," Hal declared. "What'll we do?"

"I don't know what under the sun to do," Cub replied. "I don't like to pass him up, for fear he may be telling the truth; and yet, I don't like to be the victim of a joke."

"I tell you what to do," Bud suggested, without any seriousness of intent, however. "Make a dash over the lake in your father's motor boat and rescue this Robinson Crusoe."

"By Jiminie, Bud!" exclaimed Cub enthusiastically! "You've hit the nail on the head. Our vacation problem is solved. That's what we'll do, all of us. I don't care whether it's a joke or a tragedy; we'll make a voyage of discovery over that way and see if we can't find Crusoe's island. What say you, fellows?"



CHAPTER III

Talking It Over

What could the fellows say?

They couldn't say anything at first, so astonished were they at the announcement from Cub. Then so great was their eagerness, following the recovery from their astonishment that about all they could do was to "fall over each other" in their efforts to express their approval.

At last, however, the "panic of joy" subsided, and they began to sift out the obstacles that must naturally obtrude themselves in the way of such a scheme that involved such departure from the ordinary course of events.

"Do you think your father will let us go?" asked Hal somewhat apprehensively.

"We've taken trips alone before," Cub reminded.

"Yes, but only for short trips along the shore or up the canal," Hal replied. "Ontario's a rough lake, you know."

"Yes, but safe enough if you're used to it," Bud reasoned, coming to the aid of his lanky friend. "If necessary, we could follow the bend of the shore all the way and never get out of sight of land."

"That would make the trip longer and consequently take so much more time to get there," reasoned Cub.

"Time's precious in a case like this," Hal averred. "Remember that we must get up there in time to save a fellow with no food on hand from getting an empty stomach."

"How long would the trip take?" asked Bud.

"Well, let's see," said Cub, picking up a pencil and beginning to figure on a tab of paper before him. "The Catwhisker can make twelve miles an hour under favorable conditions. We could start early in the morning and reach the Thousand Islands surely by noon, and then have the rest of the day to hunt for Mr. Robinson Crusoe."

"It might be like hunting for a needle in a haystack," suggested Hal dubiously.

"Why shouldn't we be able to find him?" Cub demanded.

"It depends on how well Mr. Crusoe can describe his surroundings for us and how well we can follow directions," Hal argued.

"That's true enough," Cub admitted. "Let's see if I can get 'im again and what he can tell us."

He had no difficulty in picking up the "desperate Mr. Crusoe" again, for the latter proved to be "sparking" the ether with frantic calls in search of the radio boy on whom he believed he had made a serious impression, but who seemed, for some unhappy reason, to have forgotten him.

"I was just discussing your case with a couple of friends," Cub explained. "We thought we might make a run down your way in a motor boat if you could give us a clear idea where your island is located."

"I can't give you any latitude and longitude," was the "islander's" reply. "I was captured in my motor boat only a mile or two away from home. Then I was blindfolded and put here on this island by the rascals. It's a small wooded island surrounded by several other small wooded islands, making it impossible for me to hail passing boats. I will be glad to pay your expenses and enough more to make it worth your while if you will find me and get me away from here."

"I don't know how we'd find you without cruising among the Thousand Islands a week or two," returned Cub. "Have you a flag of distress flying?"

"It wouldn't do any good. Nobody would see it."

"Oh, I have an idea!" suddenly exclaimed Hal, for he and Bud had put their receivers back on their ears when Cub began to communicate with "Mr. Crusoe" once more.

"Hold the wireless while I talk with my friends," Cub directed to the fellow "at the other end of the ether". Then he removed the phones from his ears, and the other boys did likewise.

"Well, what's your idea, Tee-hee?" the operator demanded with something of a tone of business challenge.

"Why, all we need is a radio compass," Hal replied. "You know I made one last summer, although I didn't have much use for it. We can install it on the boat and make a bee line for that fellow's island if he keeps his spark busy to guide us."

"Good!" exclaimed Bud. "That'll settle the biggest problem before us."

"Yes," Cub agreed. "You're a regular Thomas Edison, Jr., Tee-hee. I think we'll have to elect you captain of this expedition."

"If we make it," Bud conditioned with a slightly skeptical grin.

"My opinion, if it's worth anything to you guys," said Cub; "is that we'd better map out our plan thoroughly before we say anything about it to our fathers. Then we can put our arguments in convincing manner."

"We must finish our plan to-night, for we ought to start not later than Wednesday morning," Bud argued. "That'll give us one day to get ready in."

"We'll need all that," said Hal. "Now, let's get busy, boys, and see how near our plan is finished. It's after 10 o'clock, and I'll have to go pretty soon. If we go, we'll need—"

"Some food," itemized Bud.

"Yes, enough for us and to feed a starving Robinson Crusoe," amended Cub, beginning the list on a fresh sheet of paper.

"And drinking water."

"No. 2," commented Cub, as he jotted it down.

"And we ought to have a wireless set on hand," Hal suggested.

"Sure," said Cub. "You bring that and your loop aerial. This set is too big to transfer on board very well."

"That about completes the list, doesn't it?" asked Bud.

"We'll have to have a permit," said Hal.

"Permit for what?" Bud inquired.

"A permit from Mr. Perry to go."

"You're kidding now," said Bud. "Maybe you think this is all a joke."

"I'm afraid it is, but I'll eat my words—and glad to do it—if Cub's father and our fathers let us go."

"We've all got some persuading to do, there's no doubt o' that," Cub admitted; "but I hope we'll succeed. I'll talk to father in the morning at the breakfast table and call you fellows up an' let you know what he says. Now I'll call Mr. Robinson Crusoe again and tell 'im I'll call 'im in the morning and let 'im know what we can do."

He had no difficulty in getting the "island prisoner" again, for the latter was waiting eagerly for a message of hope. Cub, however, was cautious in this regard, saying nothing about the plan of himself and his two radio friends. He merely told "Mr. Crusoe" that he would do the best he could for him and would call him next day, specifying the hour. Then Bud and Hal went their separate ways homeward.

At 8:30 next morning Cub called Hal on the telephone and inquired:

"Hello, Hal, did you talk to your folks about our plan?"

"Yes," was the reply; "and I just got through talking with Bud over the wire before you called up."

"Well, how does it stand?"

"His folks won't let him go and my folks won't let me go unless some experienced man goes along with us."

"Hooray! we win!" yelled Cub. "Father thinks it's a peach of an adventure and he's almost as crazy over it as we were last night. He says 'yes' with a capital Y, and he'll go along with us. He says he's been wanting a vacation with some pep in it for quite a while, and this scheme of ours is ninety-nine per cent pep. If you and Bud don't go, father and I are going anyway. So get busy as fast as you can. We're off this afternoon, as early as we can get ready. I've already sent a wireless to Crusoe that we're coming. Good-bye; I'm going to call Bud now. Be over here as soon as you can and help us get ready."



CHAPTER IV

The Catwhisker

The Catwhisker, a neat gasoline power boat of the cruiser type left the private dock of the Perry home in Oswego early in the afternoon with the three radio boys and Mr. Perry on board. This had meant some rapid work by the members of the "rescue party" in preparation for the trip, for it was necessary for them to do considerable buying in the line of provisions and the transportation of a number of articles of incidental convenience, together with one complete sending and receiving wireless outfit. The hook-up of this outfit, on the boat, however, was left for a more leisurely occupation after all other preparations for the cruise were completed and they were well on their way.

The name Catwhisker harked back to the days when radio, or wireless telegraphy, was in its infancy in the experience of the three boys whose adventures are the inspiration of this volume. Mr. Perry bought the motor boat at a time when his son and the latter's two chums were busy experimenting with crystal outfits, and the name of the cruiser was suggested to them by the fine spring-wires used to make contact with the crystals in their detectors. No doubt, it was the catchiness of the word, as well as its association with their hobby, that appealed to them in the general search for a name for the boat.

This vessel was 36 feet long, with a beam of nine feet and with a canopy covering the after deck. Amidships was a raised bridge deck on which were mounted and housed the wheel and engine controls. Under this and the after deck were the engine-room and the galley, and forward of these were the cabin and two small staterooms. At the bow and in the stern were two tall slim masts that had been erected solely for the extension of a radio aerial. The hull was painted white with a blue stripe midway between the bridge-deck level and the water line.

Cub and his father were real chums in matters of boating. Mr. Perry, although ordinarily a man of very neat appearance, on the present occasion had discarded his usual sartorial excellence and appeared on the Catwhisker in clothes easily associated with cotton waste and oil cans. Indeed, he could take care of the engine quite as well as his son, who was an amateur expert, and seemed to enjoy discharging his full share, of all the "overall and apron tasks" on board.

Mr. Perry took charge of the wheel and engine controls of the yacht at the beginning of the cruise, so that his son and the other two boys were left free to perfect the hook-up of the radio set supplied by Hal. First, two wires, attached to spreaders at both ends, were extended between the two masts for an aerial, and a lead-in was arranged through one of the windows of the cabin. On a fixed table near this window they anchored firmly the various portions of Hal's sending and receiving set, in order that these might not be thrown down and damaged if the lake should become rough. As the apparatus was supplied with two steps of amplification, Hal had brought also a loud-tone horn to facilitate occasional parlor entertainment should they have leisure to listen-in to programs from various broadcasting stations within their receiving range in the course of their cruise.

Hal's outfit was by no means as elaborate or as expensive as was Cub's, but it was sufficient to receive radiophone programs, under favorable conditions, from the strongest stations 300 or 400 miles distant, while the strong spark of his code transmitter had earned for him a wide acquaintance in amateur circles.

Before they started, Cub had another dot-and-dash tete-a-tete with "Mr. Crusoe", acquainting the latter with the latest developments of their plan and requesting him to call the Catwhisker regularly at half-hour intervals if the more limited set they would take with them proved insufficient to reach him from the start.

"When we reach the Thousand Islands, we will get busy with our loop aerial and find you by radio compass," he promised.

The mysterious intermeddler who professed to have a sporting wager with the "island prisoner," was on hand with a machine-gun stream derisive waves, but Cub refused to pay any attention to him, not that he regarded that fellow's version of the affair as utterly unworthy of consideration, but, for the time being, at least, he did not wish to believe it. He was eager for the adventure, which might be spoiled if his father became convinced that "Mr. Crusoe's" SOS was a gambling hoax.

The boys took regular turns at the radio table in the cabin that afternoon and found the occupation of listening-in much more interesting than it had been at their homes, not because of any particular difference in the messages, but because of the more romantic character of their new motives and surroundings. Even the multitude of static interferences that swarmed the atmosphere on this, the first oppressively hot day of the season, were combatted with tuning coil, condenser, and detector, so confidently, although with poor success, that Mr. Perry pronounced them all "princes of patience".

In other words, the boys were in the best of spirits, all handicaps notwithstanding. Cub's father had not taken his first lesson in wireless telegraphy, and so left the radio field entirely to the three young amateur experts. In spite of the heat, they were able to get a more or less broken message now and then from the "island prisoner", but could get no acknowledgment of receipt of messages sent by them until about supper time.

"If it weren't for this heat, we probably could 'ave got a message to him as we were leaving Oswego," Cub remarked to Bud after they had been on the lake about two hours.

"The atmosphere is the worst I've ever known it to be," returned Bud, who had been laboring hard with key and spark for some time. "If it don't clear up, we may not be able to begin our hunt for him before morning."

"Well, we'll go along until half an hour before dark, I suppose, and then find a place to tie up till morning," said Cub.

He consulted his father on the subject, and the latter indorsed the plan.

The lake was rather choppy, in spite of the calmness of the day; consequently, the Catwhisker was unable to make a record run to the head of the St. Lawrence River. Ontario is not a placid lake, although it has not the heavy roughness that characterizes Lake Huron. A strong current is driven through its middle by the flood of the upper lakes after its plunge over Niagara Falls, and along the shores is a back-sweep of eddies and swirls. Hence the pilots and shippers of small boats on the lake, if they are wise, keep their weather eyes well peeled for any disturbance that may augment the natural roughness of this body of water.

Mr. Perry and his three boy companions were all well aware of the wisdom of weather caution while cruising in the Catwhisker. In the morning before starting, they had consulted the Government forecast and found the outlook favorable, but they were well aware of the fact that absolute dependence should not be put upon even so learned a being as a Great Lakes weather man.

Bud made the first score in the frequent attempts to get a message to the "island prisoner". Conditions in the ether became much better toward evening when a cool wind began to blow. Just before sending the message that reached its goal, Bud received the following from VAX:

"Where are you? Can't you reach me? Nobody in sight yet. Ate my last crust of bread an hour ago. Have to drink lake water to keep alive. Try again to get a message to me."

Bud tried again and received the following reply:

"Got you faintly. Try again. Where are you?"

But fifteen minutes elapsed before the boy at the key was able to score again. After that, however, they had no difficulty in reaching "Crusoe island" with key and spark.

Then arose the question as to whether they should attempt to find the "radio Crusoe's" island that evening or should seek a suitable mooring place and postpone the search until morning.

"There's one matter to be taken up before we decide to go much further to-night," said Mr. Perry, who had just turned the wheel over to Hal and joined the conference in the cabin.

"What's that?" asked Cub.

"The weather. We're right at the beginning of the Thousand Isles now, but we can have a nasty time of it anywhere in the upper part of the river in a storm. The wind is getting pretty lively, and you know how much the temperature has dropped."

"Oh, I can take care of that," Bud declared eagerly. "I've been having a chat with a 'ham' somewhere along the coast. I'm sure he'll get the evening forecast for me."

As he spoke, Bud dropped his eye on the log where he had made note of the shore "ham's" call and then began to tune for his wave length. To his gratification, he found the fellow busy with his spark and waited till the message was finished; then he threw his aerial switch into sending and lettered the call. The "ham" answered and asked what was wanted.

"I want the weather forecast for to-night," Bud replied. "We're out in a motor boat and want to know if it's safe to stay out till dark."

"I'll get the latest by telephone and call you back in a few minutes," was the operator's generous offer.

Ten minutes later the promised call came, thus:

"Clear to-night. Wind brisk, but not violent."

Cub was listening-in and read this message to his father.

"That means we can go on nearly three hours yet before we have to seek a post for the night," the latter announced.

"Good!" exclaimed Cub. "Now I'm going to test that radio compass and see what may be expected of it in the morning if we don't find Mr. Crusoe to-night, which isn't very likely."

Preparation for the test was simple and quickly made. The loop aerial, a collapsible affair, was set up in the cabin and connected in such manner that it could be used for receiving simultaneously with the use of the outside aerial for sending.

While Cub was thus occupied, Mr. Perry set a hasty supper of prepared foods on the table and "ate a bite". Then he returned to the chart and wheel house and relieved Hal, sending the latter back to the cabin for his meal and for further radio consultation with the other boys.



CHAPTER V

A Baffling Situation

The compass worked admirably. Although the principle of the affair was very simple, Hal must be given credit for having done his work well.

So satisfactory did the device prove from the moment when it began to take messages from the "island prisoner", that all on board the Catwhisker became hopeful of success before sun-down. "V A X" kept a stream of waves leaping from his aerial for their guidance and the motor boat chug-chugged along like a hunting hound made more and more eager by the increasing excitement of the hunt.

"I wonder what's become of the fellow who tried to head us off," remarked Hal as he left the supper table and prepared to relieve Cub at the wireless. "You haven't heard anything from him, have you?"

"No, not a thing all day," Cub replied. "I guess we've tired him out. Did you get anything from him, Bud?"

"Not a shiver of the wires," answered the latter.

"Maybe he's given us up as hopeless easy marks," Cub suggested.

"Why, do you think his story is true and 'Bobby Crusoe' is a fake?" asked Hal.

"I don't know. I wouldn't be surprised to find almost anything—or nothing—as we get near to the end of our hunt."

"But he must be on the island," Bud reasoned. "And he must have a wireless set, or he couldn't have sent the messages we got. That much is certain."

"Not all of it," Hal objected.

"Why?" Bud demanded.

"Maybe he isn't on an island."

"You mean, maybe the whole thing's a fake—eh?"

"Maybe."

"If the whole thing's a fake, then that other fellow who tried to head us off must 'ave been a party to the game," Cub interposed.

"There wouldn't be much sense in that," said Bud.

"I agree with you," Cub continued. "The scrap between those two hams was genuine enough."

"But they were holding something back from us," Hal declared.

"Both of them?" asked Bud.

"I shouldn't be surprised."

"Nor I, either," said Cub.

"Then they've put one over on us," was Bud's inference. "Are you sorry we came?"

"I? No, sir!" Cub emphasized. "It's a dandy adventure, whatever the result. I didn't swallow that Crusoe story whole at any time."

"Neither did I," said Hal.

"I thought there were some funny things about it," Bud announced reflectively; "but I didn't know how to put them together or take 'em apart."

"That was my fix," said Cub; "and it's my fix yet."

"I guess we all agree that the whole affair is very strange," Hal concluded. "We really don't believe we've been told the truth, and yet we get in worse trouble when we try to make something else out of it."

"I wonder what your father thinks about it, Cub," said Bud.

"Oh, he accepts it at its face value for the sake of the adventure," the tall youth replied. "But he's wise enough to know there may be a lot of hocus-pocus in the business."

For nearly two hours the motor boat wound its way at a fairly good clip among the picturesque islands of the upper St. Lawrence, the radio compass fixing the course as certainly as the hunter's pursuit is directed by the nose of his hound. They had no way of telling, at any time, how far ahead was the object of their search, but they had the satisfaction of knowing that they were constantly approaching it. At last an unexpected climax threw their hitherto clear prospect into confusion. This climax grew out of a series of confounding messages from the "lost islander".

"I see you coming," was the first of these messages.

"Where is he?" asked Cub and Bud in chorus. Hal was at the table and the other two boys were listening-in.

"I don't know," replied the operator. "One of you boys go on deck and see what you can see."

Cub dashed up the companionway two steps at a time. In a few moments he returned with the announcement:

"There's an open stretch of four hundred yards ahead of us. He's probably on the island at the other end. I'm going back on deck and watch for developments."

There was a speaking tube communicating between the pilot house and the cabin and through this Cub kept his boy friends acquainted with the progress of the search. They reached the island in question, but not a sign of human life was discoverable on it. The motor boat passed around it, and meanwhile the radio-compass found the strength of its receiving directly down stream. Cub communicated this condition to the cabin, and Hal dot-and-dashed the following to "VAX":

"Where are you? We can't see you."

"I saw you," was the reply. "I climbed a tree and saw you headed right for this group of islands."

"No, no," objected Hal. "It must be another yacht."

"Aren't you a white cruiser with awning mid and aft, and pilot house on bridge deck?" asked "VAX".

"Yes," answered Hal.

"There's somebody calling us," remarked Bud at this point.

"Yes, I get 'im," returned Hal. "Why, it's the mysterious guy who tried to head us off night before last and yesterday."

Both boys read the "mysterious guy's" first send with eager impatience. It was as follows:

"He's making sport of you. Mark my word, when you reach the island, he'll be gone."

"Keep out, you pirate," ordered Hal.

"All right, but you'll call yourselves a bunch of fools."

The next instant the "island prisoner" broke in thus:

"Hurry; they are after me. I think they are the ones who marooned me here. Their boat looks like yours, I guess."

"See!" exclaimed Bud. "This makes things look bad. If those fellows are robbers they're armed. We haven't a gun on board, and if we had we wouldn't want to get in a fight over an affair that looks more like a joke than a tragedy."

"And yet it may be a tragedy," said Hal.

At this moment Cub reappeared in the cabin and the situation was explained to him.

"It begins to look like a tragedy," he admitted; "and yet if we treat it as a tragedy and it proves to be a joke, we'll feel like a comedy of errors."

"Now, you're getting highbrow, Cub," was Hal's mock objection.

"It's common sense, isn't it?" the youthful philosopher reasoned.

"Yes, but you forget one thing," the sly-eyed Hal rejoined: "With so much Q R M, it's very hard to pick out common sense in an affair like this."

"That's true," replied the other. "We've had more interference in this trip thus far than anything else."

"And the big question now is, how're we goin' to tune it out?"

"I confess, I'm stumped," said Cub. "Guess we'll have to refer the whole matter to father, but I bet he'll be up against it just as much as we are."

Cub turned toward the companionway with the intention of seeking an interview with Mr. Perry in the wheel house, but Hal delayed him again.

"Wait a minute," said the operator. "Here's our island friend again."

Cub and Bud donned their phones once more. The message received was more startling than any preceding.

"They are coming ashore," was dot-and-dashed into the three boys' ears. "I see four bad-looking men. I am going to run before they see me and—maybe—swim. Good-bye."

"What in the world shall we do?" exclaimed Bud.

"I'm going to find out," declared Cub, as he dashed out of the cabin.

Hal, meanwhile, was busy again. The mysterious amateur who had persistently attempted to turn the supposed near-tragedy into a joke was spitting the Catwhisker's call again.

"Fools!" he flashed spitefully. "Goodnight."



CHAPTER VI

A Mystery and Cub's "Goat"

Cub hastened to his father and gave him a rapid narrative of events as they had been received by wireless.

"Well, that's interesting, to say the least," observed Mr. Perry with a look of curious amusement.

Cub waited a few moments for further comment, but as it was slow coming, he asked impulsively:

"What are we going to do?"

"What do you think we ought to do?" inquired the man at the wheel, looking sharply at his son.

"I don't know; I'm stumped," was the boy's reply.

"That's a frank admission. First time I've known you to admit such absolute defeat. Do you think we'd better turn about and go back home?"

"No," Cub replied with a revival of decision in his tone of voice.

"Well, shall we stop, turn to the right or left, or go ahead?"

There was a slump to indecision again. Cub looked foolish. His father was making sport of him and he did not know how to answer intelligently. In desperation, however, he replied:

"Go ahead."

"What for?" asked Mr. Perry. "Shall we dash to the rescue and face those four men, who probably are armed with pistols?"

"No, of course not. Anyway, we don't know where they are. They may be twenty-five miles from here, for all we know."

"Then we'll have to give up the search if you don't get any more messages from him," declared the boy's father.

"That's so," Cub admitted. "And if those men captured him and took him away in their boat, this affair will have to remain a mystery in our lives forever afterward."

"You'd better go back to the cabin and see if Bud and Hal got any more messages from him," suggested Mr. Perry.

"That's the only hope left," said Cub as he turned to go.

But this "last hope" proved to be vain. Bud and Hal were both still listening-in, but with little suggestion of expectancy on their countenances.

"Anything more?" inquired the tall youth, unwilling to put his question in negative form, in spite of the fact that his better judgment would have dictated it thus.

Both listeners shook their heads.

"Then that's the end of our search," Cub declared with a crestfallen and disgusted look.

"Why?" asked Bud.

"Answer the question yourself; it's easy,"

"I don't see why we should give up just because we've run up against an obstacle a little worse than any we've met before," said Hal.

"All right," Cub challenged. "Let's see what you propose to do."

"Well," Hal responded slowly; "we could go on till we found—"

He stopped and looked foolish.

"Found what?" asked Cub. "The island? How would you do that without something to guide your radio compass?"

"That's so"; Hal admitted, with another foolish look.

"It's too bad," Bud broke in, with tone well suited to his words.

"I suppose the next thing for us to do is to look for a tie-up for the night." said Hal indicating his sense of defeat by his change of subject.

"I think father is doing that now," replied Cub. "Guess I'll go and see what his idea is on that subject."

By this time the Catwhisker was several miles beyond Grindstone Island and was winding its way through a labyrinthine group to the north of Grandview. The scenery here was so enchanting that Cub and his father speedily agreed that the first convenient, unclaimed natural harbor that they discovered ought to be adopted as theirs for the night.

The season was well opened, and there were many boats on the river, so many, indeed, that it seemed strange that any live, intelligent person could be marooned on one of those islands, however vast their number, without being able to call attention to his distress. However, there were main highways in this, as in any other, semi-wilderness, and doubtless some of the by-ways were less accessible, if not less inviting and in the nature of things, less frequently visited.

This company of "rescue tourists" had motored through the Lake of the Thousand Islands before, and hence were not at a loss at any time how to find their way. The spectacle, therefore, of a hit-and-miss, crazy-quilt arrangement of long, round, high, low, green, bare islands, many of them decked with a wealth of firs, pines, tamaracks, oaks, maples, bushes and flowers, was not new to them. However, it was not long after their decision to look for a mooring place when they found an ideal cove and tied the Catwhisker to an overhanging bent, gnarled, contorted pine tree.

No camp was made on the shore, as they had no intention of remaining at this place longer than until the next break of day. All hands were pretty tired after supper, but Hal decided he must listen-in for a while before going to bed. So he donned a pair of phones and began to tune for an evening program, when a call, clear and distinct, addressed to him, suddenly held his attention.

It was from the now mysterious "V A X", the "Island Crusoe". Hal answered it and then received the following message:

"Thanks awfully for your good intentions, but I didn't need any help. Sorry to have troubled you. I did have a wager with that other fellow, but not the kind he described. It was the first big contest in the history of radio. I gave odds of four to one and am the winner. We both went to the island together and each put up an independent receiving and sending set. My part of the contest was to induce someone to come to the rescue of me as an island prisoner; his part was to head off any such rescue. He admitted I won after it was certain you were headed for us, and then we both lost our nerve and ducked. Good-bye."

Bud and Cub took the hint, from Hal's eager and almost awed manner, that something unusual was coming in through the ether and donned phones in time to catch the latter half of the message. This was sufficient to give them a clear understanding of the situation. After the "good-bye" finish, Hal made a desperate effort to hold the "Island operator" for further conversation, but could get no reply. At last he gave it up and they turned their attention to discussion of the situation.

"Well, I wonder if that's the last well hear from him," said Bud as he removed the phones from his ears, while the other two boys did likewise.

"More of a puzzle than ever, isn't it?" Cub remarked.

"Why, don't you believe the explanation he telegraphed to us?" Hal inquired.

"I do not," the tall youth replied positively.

"Why not?" Hal persisted. "Doesn't it satisfy your lordship?"

"Cut it out, Tee-hee," the alleged "lordship" ordered. "You make me sore."

"Then I'll rub on some salve."

"If you do, you'll get your fingers burnt," Cub retorted.

"I always thought you were a hot one. But that doesn't answer the question before us."

"No, because we don't know how to settle it," Cub admitted. "If we knew what we're talkin' about, we wouldn't be batting this nonsense back and forth. We can't hit the nail on the head, so we just fan the air. By the way, what did that fellow say before Bud and I began to listen-in?"

Hal reviewed the first half of the statement received by him. Then Mr. Perry, who had just returned from ashore, where he had been testing the security of the tie-up, entered the cabin.

"What's the trouble, boys?" he asked, noting the studied expression of their faces.

"No trouble, exactly," Cub replied. "Just another mystery."

"That's interesting," the yachtsman commented. "Tell me about it."

"You get my goat, dad," Cub declared.

Mr. Perry laughed.

"Why do I get your goat, Bob?" he asked.

"Because the more mystery there is floating around, the better pleased you are."

"Is that so? Well, what's the mystery now?"

"You tell 'im, Hal," requested the youth of the "goat-got affliction".

Hal did as requested. Quiet of several moments followed.

"Well?" Mr. Perry interrogated.

"Well!". repeated Cub vociferously. "Is that all you can say?"

"I'd like to return your goat, Bob, but I don't see how I can," Mr. Perry announced provokingly.

"In other words, you don't see anything startling about that fellow's last performance," Cub inferred.

"No—o, nothing startling," his father replied slowly.

"What do you make out of it, then?"

"I don't know that I make anything out of it, except a lot of nonsense."

"You think it's a joke?"

"I wouldn't call it anything but a lot of nonsense until I know more about it."

"But doesn't it make you impatient to find out what it all means?" Cub demanded.

"No, not in the least. I got over that long ago, my son. Don't let any such habit grip you; it'll wear your nerves out, and then you won't have any lead-in to connect your antennae with your brains."

"Ha, ha, ha," laughed the man's youthful audience in chorus, even Cub appreciating the illustration.

"When did you begin to study radio, Mr. Perry?" asked Bud.

"Oh, I've been learning rapidly ever since I was thrown into the company of you hams," was the reply. "But don't let me get you off the question."

"The question—what was the question?" asked Cub, digging his fingers into his rather lengthy locks of hair.

"Mystery, wasn't it?" reminded Mr. Perry.

"Yes, that's it," Bud replied. "The mystery of the Radio Robinson Crusoe in the Lake of the Thousand Isles."

"That sounds interesting, but it's mostly a poetic, or ecstatic, jumble of words," said Mr. Perry. "And right there is the secret of many a mystery. It's clothed in a maze of language. Remove the maze, and it begins to look simple."

"Where is the maze of language in this affair?" Cub challenged.

"From what I've heard, the whole affair seems to have consisted principally of language. Now, I tell you what we'll do. We'll go to bed early and have a good sleep. In the morning, we'll shake this affair up in a sieve and see if we can't get rid of everything but the main lumps of the facts. Then we'll size them up and see what we can make of them. In my opinion, we can get at the bottom of what you choose to regard as a profound mystery."

"If you do, pa, you'll return my goat," said Cub.

"It's up to you, Bob," was his father's reply. "I've no desire to keep him in my stable."



CHAPTER VII

Returning Cub's "Goat"

In the morning after breakfast Mr. Perry called a conference on deck for the purpose of discussing "the mystery and Cub's goat", as Hal put it.

"Yes," said Bud, his sense of humor stimulated by this allusion; "all Mr. Perry has to do to return Cub's goat is to prove there isn't any mystery about the affair."

"I didn't say I was going to do that," objected the adult member of the party.

"What—return the goat or disprove the mystery?" asked Bud.

"Now you're getting facetious," broke in Cub.

"Not necessarily," objected Mr. Perry. "I didn't promise, or have in mind, to do either of those things. The fact of the matter is, a mystery represents the state or condition of mind of the person mystified. Now, I am not mystified over this affair at all; hence there is no mystery in it, so far as I am concerned."

"Then explain it to us," Bud challenged.

"Oh, no; I didn't mean I could do that."

"Then you must be mystified," Bud argued.

"Suppose you have a difficult example to do at school, and finally after working at it a long time you have to confess you can't do it—does that mean it's a mystery and you are mystified?"

This was a poser for the boys. They had never looked at a subject of this kind on any such light.

"Cub, you're the highbrow of our bunch," said Hal after some moments of puzzled silence.

"Oh, get away with that stuff," Cub protested, but, somehow, a faint glimmer of satisfaction at the "compliment" shone in his countenance.

"No, I won't, either," Hal insisted. "It's true. This thing is too much for Bud and me. You've got to settle it for us."

Cub "swelled up" a little with importance at this admission. He was sitting in a camp chair with his feet resting on the taffrail, it being a habit of his to rest his feet on something higher than his head, if possible, whenever seated. Now, however, there seemed to be a demand for superior head-work, so he lowered his feet, straightened up his back, and said:

"Well."—speaking slowly—"I don't want to get in bad with my father by trying to prove I know more than he does, but my argument would be that all of life is not arithmetic."

"Good!" exclaimed Hal, eager to defend his belief in things mysterious, and Bud signified his approval in similar manner.

"Yes, that isn't bad at all," admitted Mr. Perry, glad to have stimulated his son's mind into action. "But if we can't explain this affair with mathematics, maybe we can explain it by some other element of human education."

"What, for instance?" asked Cub. "Not by readin', 'ritin', or 'rithmetic."

"No, we'll exclude the three R's for the present, although all of them may figure in our work before it is finished."

"Well," mused Cub; "the others are history, geography, spelling—"

"Why didn't you stop with geography?" asked his father.

"Geography!" exclaimed Bud. "How can you use that to explain a mystery?"

"It depends on whether geography is involved," Mr. Perry replied. "In this case it seems to me that geography is a very important element. We may have to know considerably more about the geography of the Thousand Islands in order to solve this so-called mystery. Now, mind you, I don't mean to say that we're going to get at the bottom of this affair, but I do want to suggest that if it is to be solved by any systematic process, the first elements to be employed in the process are a little geography and a little arithmetic. With this in view, I would suggest that you get busy with your wireless outfit and see what you can find out."

The three boys gazed curiously at Cub's father and then at one another in a puzzled manner.

"Haven't I given you enough hint?" asked Mr. Perry. "I don't want to do the work myself—in fact, I couldn't if I wished to, for I can't send a wireless message; but if I could, I know exactly what I'd do."

"We might send a broadcast to all other amateurs and find out if any of them can help us," Hal suggested.

"How could they help us?" asked Bud skeptically.

"I'm sure I can't tell you," replied Mr. Perry. "But you have a dandy field to work on. All you need is a little imagination; then begin to do a little head-work, and before you know it you'll have a lead to work on. And let me add something more. There are two things in this world, which, working together, can knock a mystery into a cocked hat more successfully than anything else in the world that I know of."

"I bet I know what they are," Cub volunteered, eagerly.

"Mathematics and imagination," almost shouted Hal in a wild scramble of mind to beat Cub with the answer.

The latter cast a wrathful glance at the saucy youth who had broken in ahead of him.

"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 space 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 passed 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 circumnavigated 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 passed their first night in the Thousand Islands. The finny fellows bit greedily and in a short time they had enough black bass 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.

"You mean problem," reminded Mr. Perry with a smile.

"Well, maybe,—I won't dispute your word since your idea has proved so brilliant thus far—but I can't see the mathematics yet."

"Nor the geography?"

"Well, yes; it took us from Kingston to Port Hope and from there to Edwards College," Cub admitted. "I suppose there's a little geography in that."

"Remember this, that mathematics isn't all figures," said the operator's father. "Keep that in mind, and maybe it'll be worth something to you before we're through with this affair."

"How does the discovery of my cousin come in?" Hal inquired. "Is that geography or mathematics?"

"Do you mean that, Hal?" asked Bud wonderingly. "You don't mean that fellow is really your cousin?"

"I surely do, if he's Alvin Baker. You know my folks used to live in Canada. And don't you remember that my cousin Al visited us three years ago with his father and mother? He wrote to me several times from Edwards College, but I didn't know he had a wireless set, and I suppose he didn't know I had one."

"Well, it makes the hunt more interesting, anyway," said Cub. "But let's not waste any more time. Here goes again."

He called the other Canadian amateur on his list of three and learned from him that many wireless boys had followed the course of the rescue boat with their receiving outfits. From him Cub got the calls of four of these interested boys. Then he called the third on his original list, but all the information the latter was able to give was that a metropolitan morning newspaper carried a column "story" on the front page about the Thousand Island Crusoe and the rescue boat from Oswego.

"You're right again, dad," said Cub, with a grim grin of subdued wonder and eagerness.

"I shouldn't be a bit surprised to find that the Associated Press has chartered a boat and is following us," declared Mr. Perry.

"Would that be mathematics or geography?" asked Bud.

"It would be imagination," replied Mr. Perry with a keen smile. "But, say, Cub, don't you think you've grabbed off enough glory for yourself? Give your friends a chance to win some honors."

"Right you are, dad," returned the boy at the key, rising and removing the phones from his ears. "Hal, you call half this list and then let Bud call the rest"

It was well for the sake of a distribution of honors that this course was taken, for a thrilling surprise was in store for them in response to the next call.



CHAPTER IX

The Radio Diagram

As good fortune decreed, Hal found Number One in the new list sitting in and listening for anything interesting in the ether. It required only a few short sentences to acquaint this amateur with the object of the Catwhisker's search.

"I can tell you just how to find those fellows," he replied. "I listened-in to the best line of detective work on that subject you ever heard of. Sherlock Holmes isn't in it there."

"Hooray!" shouted Bud, as he finished jotting down the last sentence.

"There are three amateurs, one in Clayton, N.Y., one in Rockport and one in Gananoque, Ontario, who have radio compasses and they worked together to locate the fellow on the island," continued the informant with the eagerness of fraternal interest and generosity. "I will give you their calls—"

The message was interrupted by a strong spark, which could not be ignored. Sender Number one stopped sending, and Hal gave ear to the new message.

"I will save you the trouble," read the dots and dashes evidently addressed to the operator he had just "crowded out," "I am at Rockport and am one of the three radio compass boys referred to. I can supply the dope right now."

Hal threw over the aerial switch and flashed the one word "Shoot!" Then he swung back again and all three boys listened eagerly.

"Have you a good map of the Thousand Island region?" inquired the loop aerial operator.

"Yes," Hal replied.

"Well, take these directions and then draw the line on the map. Draw one line from Clayton, N.Y., northeast, 47-1/2 degrees from perpendicular; another from Rockport, Ontario, southeast, 11 degrees from perpendicular; another from Gananoque, southeast, 76 degrees from perpendicular. The intersection of those lines will indicate the island those messages came from."

"He was on an island, was he?" asked Hal.

"Sure, or on a boat," was the reply. "He could not have been on the mainland. We were careful and could not have been more than a mile off in our reckoning. All three of us hit it the same."

"Where was the fellow who tried to head us off?" asked Hal.

"When?"

"At any time."

"We located him at various points along the river. No doubt he was on a boat up to the very last when the two were very near together."

"Where was the island operator when he sent his last message? Did you get the one in which he confessed the affair was a hoax?"

"Yes. But he did not send that message. It was sent by the other fellow."

"How do you know?"

"That was plain. Did you not notice his peculiar manner of sending? All three of us noticed that."

"Did you pick up any more from them since then?"

"Not a dot."

Hal then asked the obliging amateur to indicate as nearly as possible the location of the island from which the messages came. The latter did as requested, and Hal marked the point on the chart of the St. Lawrence River carried by the Catwhisker. This closed the wireless interview. Hal promised to report back to the Rockport amateur any further developments of interest and tapped "goodnight" with his key.

"Well, your two main points have been proved, Mr. Perry," Bud announced as all three boys removed the receivers from their ears.

"What are they?" asked the man thus addressed.

"Mathematics and geography."

Mr. Perry smiled.

"Yes," he said "I could hardly have hoped for so remarkable a demonstration of my theory. You boys have solved the geography of this problem with the aid of some very clever mathematics. But what branch of mathematics is it?"

"We didn't do it ourselves," Hal reminded. "It was those three amateurs with their loop aerials."

"Wasn't it more mechanical than mathematical?" Cub inquired meditatively. "Those radio compasses make me think of a surveyor's instrument."

"Oh, pshaw, my boy, don't spoil everything," pleaded the last speaker's father. "I'm afraid you've missed the big point. Mathematics is the biggest factor in all mechanics. Bud, I thought from the way you spoke that you grasped the situation completely. Can't you help Bob and Hal out? By means of what branch of mathematics was that island of our Canadian Crusoe located?"

"Geometry," replied Bud confidently.

Cub snapped his finger with an impatient jerk of his long right arm.

"Of course!" he exclaimed in disgust. "Every branch of mathematics I ever heard of, except geometry, went buzzing through my head. I was trying to recall something in algebra that would fit this case."

"Oh, Cub," laughed Hal; "algebra is all x's and y's and z's over z's and y's and x's,"

"I admit I'm a chump," Cub grinned with a shrug of self-commiseration; "but say, let's draw those geometrical lines on our chart and see if we get the same result those radio compass fellows got."

Cub produced the chart and a hand-book diagram of a mariner's compass about three inches in diameter. Fortunately the chart was made of thin, vellum-like paper, almost transparent, so that when laid over the diagram, the minute points of the compass, indicated with clear black lines, could be seen through. First the dot representing the town of Clayton was placed over the point at the center of the compass, with the north and south line of the compass exactly coinciding with the meridian of the town. Then Cub traced on the chart lightly with a pencil the 47-1/2-degree northeast line of the compass. Next he performed a similar operation with the center of the diagram over Rockport and next with the center of the diagram over Gananoque, following instructions in each of these cases with reference to the direction lines to be drawn. The result was that the intersection of the three lines was at approximately the point indicated by the Rockport amateur.

"Now we're ready to continue our search," Cub announced.

"That's pretty good progress, I must say," Bud declared; "but here's a new question to get us into trouble again."

"Oh, for goodness sake, don't," pleaded Cub. "You've had your example of what my mathematical dad can do with such foolish creatures."

"Let him express his doubt," suggested Mr. Perry with a smile; "for, if a man must doubt, he'd better shout than smother his ideas in a skeptic pout."

"Yes, get it off your chest, Bud, and then take your medicine," advised Hal.

"Well, suppose we find the island and nobody there, how are we going to know it's the right one?"

This hit the other two boys pretty hard. The possibility of such a situation had not occurred to either of them. However, Cub preferred to take it in lighter vein, for he replied:

"By his footprints on the sandy beach. You mustn't have a Crusoe Island without some footprints, you know."

"The trouble is you're anticipating too rapidly, Bud," Mr. Perry advised. "Columbus would never have discovered America in that frame of mind."

"All right, I'll change the frame," said Bud. "We'll just go ahead and see what we shall see."

"We've got to go ahead if Hal's cousin is in peril," declared Cub.

"Do you really believe the Crusoe boy is your cousin, Hal?" asked Bud.

"Of course that's hard to believe, but the evidence points in that direction," Hal replied.

"At least if he is your cousin, we know now that he wasn't making monkeys out of us, as that last message, supposed to come from him, made it appear he was doing," Cub admitted.

"Yes," put in Mr. Perry; "it looks now as if he was telling a straight story all along."

"If that's true, then he's probably in serious trouble right now," said Hal.

"Probably a prisoner in the hands of robbers, if not worse," Bud supplemented.

"Let's go to bed at once and get a good night's rest so that we will be in condition to put forth our best efforts to find him and rescue him in the morning," proposed Mr. Perry.

This proposal met with indorsement from all, and in a short time they were in their berths, employing their best skill to induce sleep under condition of much mental excitement.



CHAPTER X

The Island-Surrounded Island

Early next morning the Catwhisker left its mooring under the tamarack and started on the new search for the "Canadian Crusoe's" island.

Guided by the "mathematical chart" prepared with the directions given by the radio-compass amateur, the crew of the motor boat had little difficulty in finding the approximate location of the island prison; but when arrived there, they realized that considerable work was still before them, for they were in the midst of a veritable sea of islands, varying in size from a few car-loads of stone and earth to several acres in extent.

"Well, how are we goin' to begin?" asked Hal as Cub stopped the engine in a pond-like expanse, surrounded by a more or less regular rim of islands.

"The first thing to do, I should say is to make the best possible reckoning of our bearings and then try to fix the point of intersection of those three lines indicated by the radio compasses," said Mr. Perry.

"That's right," Cub agreed. "We mustn't forget our mathematics."

"It seems to me that we ought to be able to pick this place on the chart," Bud suggested.

"Yes, especially if we keep in mind the location of some other landmarks, or watermarks, that we passed in the last half or three-quarters of an hour in getting here," said Hal.

Cub produced the chart, and the study of locations and island arrangements began. As indicated by expectations in the course of their discussion, they were able to locate a few of the larger islands and with these as bases for further reckoning, they at last picked out what seemed to be the point of intersection of the three pencil lines on the chart. This necessitated a little more cruising about, but within an hour after their first stop they completed their reckoning.

"There's the island that seems to come nearest to the intersection," said Mr. Perry, pointing toward an abrupt elevation, a hundred yards long and half as wide and covered with bushes and a few small trees; "but it doesn't seem to answer the description very well. No other islands near it."

"I don't see how anybody could be marooned on that place with boats passing back and forth near it every hour of the day," Hal commented skeptically.

"Neither do I," Bud agreed.

"Well, let's do our work thoroughly anyway," Mr. Perry suggested.

"Shall we go ashore and look that place over?" asked Hal.

"Sure."

"But what do you expect to find?" Cub inquired.

"I don't expect to find anything. I had no expectation when I suggested that you boys canvass the radio field for information to clear up what you chose to call a mystery. I had no idea what might turn up as a result of such canvass, but I know it was about the only thing for you to do to start a move in the desired direction."

"And something sure did move," Hal remarked appreciatively.

"Well, let's run around this island and find a landing place," Cub proposed.

The run was made, with Cub in charge of the wheel and engine controls. They circumnavigated the island with unsatisfactory result.

"That settles it," Bud declared. "If San Salvador had been like that, Columbus would have made his first landing somewhere else!"

"Robinson Crusoe would never have found any footprints in the sand there," Hal declared.

"Yes, we'll give it up for the time being," Mr. Perry declared. "We won't try to scale any perpendicular banks, fifteen or twenty feet high, at least, not to begin with."

"I tell you what we ought to do," Hal volunteered next. "Let's accept this island as the center of probability."

"What in thunder is that?" Cub demanded.

"That's a good one on you, son," laughed the latter's father. "I thought you were the highbrow of your bunch; but here's our subtle Tee-hee putting a bit of clever phraseology over on you."

"Oh, I know what he means," Cub rejoined with a panicky haste to recover lost prestige. "I was just giving him a dig. He's forever giving me one, whenever I come along with anything of that kind."

"It indicates that his mind is maturing rapidly," said Mr. Perry. "All right, Hal, we'll accept this island as a center of probability—what next?"

"Why, let's cruise around about half a mile in all directions and pick out those islands that look as if they might have concealed a prisoner from view of passing boats."

"That's a good suggestion," said Mr. Perry. "Bob, start the boat again."

The inspection required about an hour, at the end of which they compared notes and found that their island inventory disclosed the following conditions:

Three possible places of concealment for the "Canadian Crusoe" had been discovered. Two were small islands a short distance from each other in a region of shallows and more or less hidden by rows of long slim islands. No boat of greater draught than a canoe could make its way through the intervening passages. In other words, these islands were virtually isolated from all river traffic. The other possible place of concealment was an island about five acres in extent, completely hemmed in by a group of other islands, which were so overrun with rampant vegetation, including bushes and trees, as to conceal the inner isle from any but the most scrutinizing vision.

"That is the place we want to explore first," announced Mr. Perry as reference was made to this retreat in the check-up.

"I agree with you," Bud declared. "If the prisoner left any traces behind him at all, we're likely to find them on that island in there."

"Is there any way we can get in?" Hal inquired. "Too bad we haven't a small rowboat or canoe with us."

"We'll investigate and see what we can find in the way of a water passage into the interior," Mr. Perry announced.

"That means a little more circumnavigating," Bud inferred.

"Right you are," said Cub. "Me to the pilot house again."

Accordingly he resumed his position at the wheel and the boat was put in motion again. His father followed him and cautioned him against too much speed in such places.

Slowly the Catwhisker crept around the island-surrounded island until they discovered a passage somewhat wider and apparently deeper than others they had seen thus far in the outer rim.

"It looks as if we might get through there," suggested Hal. He and Bud had followed into the pilot house soon after Cub and his father repaired to that place.

"It does look a little that way," replied Mr. Perry.

"We might creep in there slowly, and if we find the passage obstructed so as to block our way, we could back out," Hal continued.

"We have some long fender poles," Cub amended. "We could feel our way with them and probably keep out of serious trouble."

"All right, let's make the attempt," said Mr. Perry. "I'd very much like to get in there with this boat."

Cub started the engine and the Catwhisker began slowly to nose its way through the passage. In a few minutes the little craft was alongside a ledge of rock that projected as a sort of forehead from the top of a perpendicular short front, and the pilot brought her to a full stop.



CHAPTER XI

The Deserted Camp

Both the inner island and the surrounding rim of elongated isles were covered with a thick growth of trees and bushes, a condition that caused Hal to exclaim:

"I bet this is the place."

"What makes you so certain of that?" inquired Mr. Perry, looking sharply at the boy.

"Because it's an ideal place for a Crusoe to be hidden so that passing ships could not see him," Hal replied.

"But might he not swim over to one of these surrounding islands and attract attention from there?"

"Yes, if there's a place to get ashore after swimming across," said Cub.

"There's nothing but high steep banks all along here, so far as I can see," Bud remarked.

"That's a good line of observation," was Mr. Perry's commendation. "Now, let's explore this island and see if your points are well taken."

Even the landing at which the boat now rested was not particularly attractive as such at first view because of a rather difficult climb between it and the main level of the island. However, all the members of the band of "Crusoe hunters" were good climbers and they soon made their way up the stony steep to the surface land level.

"It's funny somebody hasn't picked this place as a site for a summer home," Mr. Perry remarked as he took a hurried view of his surroundings.

"The trouble is it doesn't look like a very interesting place from a view out on the river, and there are hundreds of islands to choose from," said Cub.

"Yes, I suppose so," his father agreed; "but in my opinion the place deserves a second look-over. I'm going to keep it in mind as a future prospect."