The Radio Boys Series (Trademark Registered)

THE RADIO BOYS TRAILING A VOICE

Or

Solving a Wireless Mystery

by

ALLEN CHAPMAN

Author of The Radio Boys' First Wireless The Radio Boys at Mountain Pass Ralph of The Roundhouse Ralph on the Army Train, Etc.

With Foreword by Jack Binns

Illustrated



New York Grosset & Dunlap Publishers

Made in the United States of America

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BOOKS FOR BOYS BY ALLEN CHAPMAN

12mo. Cloth. Illustrated.

THE RADIO BOYS SERIES (Trademark Registered)

THE RADIO BOYS' FIRST WIRELESS Or Winning the Ferberton Prize

THE RADIO BOYS AT OCEAN POINT Or The Message that Saved the Ship

THE RADIO BOYS AT THE SENDING STATION Or Making Good in the Wireless Room

THE RADIO BOYS AT MOUNTAIN PASS Or The Midnight Call for Assistance

THE RADIO BOYS TRAILING A VOICE Or Solving a Wireless Mystery

THE RAILROAD SERIES

RALPH OF THE ROUNDHOUSE Or Bound to Become a Railroad Man

RALPH IN THE SWITCH TOWER Or Clearing the Track

RALPH ON THE ENGINE Or The Young Fireman of the Limited Mail

RALPH ON THE OVERLAND EXPRESS Or The Trials and Triumphs of a Young Engineer

RALPH THE TRAIN DESPATCHER Or The Mystery of the Pay Car

RALPH ON THE ARMY TRAIN Or The Young Railroader's Most Daring Exploit

GROSSET & DUNLAP, Publishers, New York

Copyright, 1922, By GROSSET & DUNLAP

The Radio Boys Trailing a Voice

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FOREWORD

BY JACK BINNS

Within a comparatively short time after this volume is published the human voice will be thrown across the Atlantic Ocean under conditions that will lead immediately to the establishment of permanent telephone communication with Europe by means of radio.

Under the circumstances therefore the various uses of radio which are so aptly outlined in it will give the reader an idea of the tremendous strides that have been made in the art of communicating without wires during the past few months.

Of these one of the most important, which by the way is dealt with to a large extent in the present volume, is that of running down crooks. It must not be forgotten that criminals, and those criminally intent are not slow to utilize the latest developments of the genius of man, and radio is useful to them also. However, the forces of law and order inevitably prevail, and radio therefore is going to be increasingly useful in our general police work.

Another important use, as outlined in this volume, is in the detection of forest fires, and in fact generally protecting forest areas in conjunction with aircraft. With these two means hundreds of thousands of acres can now be patrolled in a single day more efficiently than a few acres were previously covered.

Radio is an ideal boy's hobby, but it is not limited to youth. Nevertheless it offers a wonderful scope for the unquenchable enthusiasm that always accompanies the application of youthful endeavor, and it is a fact that the majority of the wonderful inventions and improvements that have been made in radio have been produced by young men.

Since this book was written there has been produced in this country the most powerful vacuum tube in the world. In size it is small, but in output it is capable of producing 100 kilowatts of electrical power. Three such tubes will cast the human voice across the Atlantic Ocean under any conditions, and transmit across the same vast space the world's grandest music. Ten of these tubes joined in parallel at any of the giant transmitting wireless telegraph stations would send telegraph code messages practically around the world.



CONTENTS

I. Splintering Glass 9 II. In a Dilemma 20 III. The Stuttering Voice 31 IV. A Puzzling Mystery 43 V. Marvels of Wireless 51 VI. The Forest Ranger 61 VII. Radio and the Fire Fiend 70 VIII. Near Disaster 77 IX. A Happy Inspiration 83 X. The Escaped Convict 91 XI. Down the Trap Door 99 XII. Groping in Darkness 106 XIII. Cunning Scoundrels 112 XIV. A Daring Holdup 119 XV. Off to the Woods 127 XVI. Put to the Test 136 XVII. The Bully Gets a Ducking 143 XVIII. A Startling Discovery 151 XIX. The Robbers' Code 160 XX. On the Trail 168 XXI. The Glimpse Through the Window 177 XXII. A Nefarious Plot 185 XXIII. Preparing an Ambush 193 XXIV. Lying in Wait 202 XXV. An Exciting Struggle 208



CHAPTER I

SPLINTERING GLASS

"You fellows want to be sure to come round to my house to-night and listen in on the radio concert," said Bob Layton to a group of his chums, as they were walking along the main street of Clintonia one day in the early spring.

"I'll be there with bells on," replied Joe Atwood, as he kicked a piece of ice from his path. "Trust me not to overlook anything when it comes to radio. I'm getting to be more and more of a fan with every day that passes. Mother insists that I talk of it in my sleep, but I guess she's only fooling."

"Count on yours truly too," chimed in Herb Fennington. "I got stirred up about radio a little later than the rest of you fellows, but now I'm making up for lost time. Slow but sure is my motto."

"Slow is right," chaffed Jimmy Plummer. "But what on earth are you sure of?"

"I'm sure," replied Herb, as he deftly slipped a bit of ice down Jimmy's back, "that in a minute you'll be dancing about like a howling dervish."

His prophecy was correct, for Jimmy both howled and danced as he tried vainly to extricate the icy fragment that was sliding down his spine. His contortions were so ludicrous that the boys broke into roars of laughter.

"Great joke, isn't it?" snorted Jimmy, as he bent nearly double. "If you had a heart you'd lend a hand and get this out."

"Let's stand him on his head," suggested Joe. "That's the only thing I can think of. Then it'll slide out."

Hands were outstretched in ready compliance, but Jimmy concluded that the remedy was worse than the presence of the ice and managed to keep out of reach.

"Never mind, Jimmy," said Bob consolingly. "It'll melt pretty soon, anyhow."

"Yes, and it'll be a good thing for Jimmy to grin and bear it," added Herb brightly. "It's things like that that develop one's character."

"'It's easy enough to be pleasant, when life moves along like a song, but the man that's worth while, is the man who can smile when everything's going dead wrong,'" quoted Joe.

Jimmy, not at all comforted by these noble maxims, glared at his tormentors, and at last Bob came to his relief, and, putting his hand inside his collar, reached down his back and brought up the piece of ice, now greatly reduced in size.

"Let's have it," demanded Jimmy, as Bob was about to throw it away.

"What do you want it for?" asked Bob. "I should think you'd seen enough of it."

"On the same principle that a man likes to look at his aching tooth after the dentist has pulled it out," grinned Joe.

"Don't give it to him!" exclaimed Herb, edging away out of reach, justly fearing that he might feel the vengeance of the outraged Jimmy.

"You gave it to him first, so it's his," decided Bob, with the wisdom of a Solomon, as he handed it over to the victim.

Jimmy took it and started for Herb, but just then Mr. Preston, the principal of the high school, came along and Jimmy felt compelled to defer his revenge.

"How are you, boys?" said Mr. Preston, with a smile. "You seem to be having a good time."

"Jimmy is," returned Herb, and Jimmy covertly shook his fist at him. "We're making the most of the snow and ice while it lasts."

"Well, I don't think it will last much longer," surmised Mr. Preston, as he walked along with them. "As a matter of fact, winter is 'lingering in the lap of spring' a good deal longer than usual this year."

"I suppose you had a pleasant time in Washington?" remarked Joe inquiringly, referring to a trip from which the principal had returned only a few days before.

"I did, indeed," was the reply. "To my mind it's the most interesting city in the country. I've been there a number of times, and yet I always leave there with regret. There's the Capitol, the noblest building on this continent and to my mind the finest in the world. Then there's the Congressional Library, only second to it in beauty, and the Washington Monument soaring into the air to a height of five hundred and fifty-five feet, and the superb Lincoln Memorial, and a host of other things scarcely less wonderful.

"But the pleasantest recollection I have of the trip," he went on, "was the speech I heard the President make just before I came away. It was simply magnificent."

"It sure was," replied Bob enthusiastically. "Every word of it was worth remembering. He certainly knows how to put things."

"I suppose you read it in the newspaper the next day," said Mr. Preston, glancing at him.

"Better than that," responded Bob, with a smile. "We all heard it over the radio while he was making it."

"Indeed!" replied the principal. "Then you boys heard it even before I did."

"What do you mean?" asked Joe, in some bewilderment. "I understood that you were in the crowd that listened to him."

"So I was," Mr. Preston answered, in evident enjoyment of their mystification. "I sat right before him while he was speaking, not more than a hundred feet away, saw the motion of his lips as the words fell from them and noted the changing expression of his features. And yet I say again that you boys heard him before I did."

"I don't quite see," said Herb, in great perplexity. "You were only a hundred feet away and we were hundreds of miles away."

"And if you had been thousands of miles away, what I said would still be true," affirmed Mr. Preston. "No doubt there were farmers out on the Western plains who heard him before I did.

"You see it's like this," the schoolmaster went on to explain. "Sound travels through the air to a distance of a little over a hundred feet in the tenth part of a second. But in that same tenth of a second that it took the President's voice to reach me in the open air radio could have carried it eighteen thousand six hundred miles."

"Whew!" exclaimed Jimmy. "Eighteen thousand six hundred miles! Not feet, fellows, but miles!"

"That's right," said Bob thoughtfully. "Though I never thought of it in just that way before. But it's a fact that radio travels at the rate of one hundred and eighty-six thousand miles a second."

"Equal to about seven and a half times around the earth," observed the principal, smiling. "In other words, the people who were actually sitting in the presence of the President were the very last to hear what he said.

"Put it in still another way. Suppose the President were speaking through a megaphone in addition to the radio and by the use of the megaphone the voice was carried to people in the audience a third of a mile away. By the time those persons heard it, the man in the moon could have heard it too—that is," he added, with a laugh, "supposing there really were a man in the moon and that he had a radio receiving set."

"It surely sounds like fairyland," murmured Joe.

"Radio is the fairyland of science," replied Mr. Preston, with enthusiasm, "in the sense that it is full of wonder and romance. But there the similarity ceases. Fairyland is a creation of the fancy or the imagination. Radio is based upon the solid rock of scientific truth. Its principles are as certain as those of mathematics. Its problems can be demonstrated as exactly as that two and two make four. But it's full of what seem to be miracles until they are shown to be facts. And there's scarcely a day that passes without a new one of these 'miracles' coming to light."

He had reached his corner by this time, and with a pleasant wave of his hand he left them.

"He sure is a thirty-third degree radio fan," mused Joe, as they watched his retreating figure.

"Just as most all bright men are becoming," declared Bob. "The time is coming when a man who doesn't know about radio or isn't interested in it will be looked on as a man without intelligence."

"Look here!" exclaimed Jimmy suddenly. "What's become of my piece of ice?"

He opened his hand, which was red and wet and dripping.

"That's one on you, Jimmy, old boy," chuckled Joe. "It melted away while you were listening to the prof."

"It's an ill wind that blows nobody good," said Herb complacently. "Jimmy meant to put that down my back."

"Oh, there are plenty of other pieces," said Jimmy, as he picked one up and started for Herb.

Herb started to run, but slipped and fell on the icy sidewalk.

"You know what the Good Book says," chaffed Joe. "The wicked stand on slippery places."

"Yes, I see they do," replied Herb, as quick as a flash, looking up at him. "But I can't."

The laugh was on Joe, and Herb felt so good over the retort that he did not mind the fall, though it had jarred him considerably. He scrambled to his feet and brushed off his clothes, while Jimmy, feeling that his comrade had been punished enough, magnanimously threw away the piece of ice that was to have been the instrument of his vengeance.

"The reason why I wanted you fellows to be sure to be on hand to-night," resumed Bob, as they walked along, "was that I saw in the program of the Newark station in the newspaper this morning that Larry Bartlett was down for an entirely new stunt. You know what a hit he made with his imitations of birds."

"He sure did," agreed Joe. "To my mind he had it all over the birds themselves. I never got tired listening to him."

"He certainly was a dabster at it," chimed in Jimmy.

"Now he's going in to imitate animals," explained Bob. "I understand that he's been haunting the Zoo for weeks in every minute of his spare time studying the bears and lions and tigers and elephants and snakes, and getting their roars and growls and trumpeting and hisses down to a fine point. I bet he'll be a riot when he gives them to us over the radio."

"He sure will," assented Herb. "He's got the natural gift in the first place, and then he practices and practices until he's got everything down to perfection."

"He's a natural entertainer," affirmed Bob. "I tell you, fellows, we never did a better day's work than when we got Larry that job at the sending station. Not only was it a good thing for Larry himself when he was down and out, but think of the pleasure he's been able to give to hundreds of thousands of people. I'll bet there's no feature on the program that is waited for more eagerly than his."

By this time the boys had reached the business portion of the town and the short spring day was drawing to a close. Already lights were beginning to twinkle in the stores that lined both sides of the street.

"Getting near supper time," remarked Bob. "Guess we'd better be getting along home. Don't forget to come—Gee whiz!"

The ejaculation was wrung from him by a snowball that hit him squarely in the breast, staggering him for a moment.

Bang! and another snowball found a target in Joe. It struck his shoulder and spattered all over his face and neck.

"That felt as though it came from a gun!" he exclaimed. "It's the hardest slam I ever got."

"Who did it?" demanded Bob, peering about him in the gathering darkness.

Halfway up the block they saw a group of dark figures darting into an alleyway.

"It's Buck Looker and his crowd!" cried Jimmy. "I saw them when they ran under that arc light."

"Just like that crowd to take us unawares," said Bob. "But if they're looking for a tussle we can accommodate them. Get busy, fellows, and let them have something in return for these two sockdolagers."

They hastily gathered up several snowballs apiece, which were easily made because the snow was soft and packed readily, and ran toward the alleyway just in time to see Buck and his crowd emerging from their hiding place.

There was a spirited battle for a few minutes, each side making and receiving some smashing hits. Buck's gang had the advantage in that they had a large number of missiles already prepared, and even in the excitement of the fight the radio boys noticed how unusually hard they were.

"Must have been soaking them in water until they froze," grunted Jimmy, as one of them caught him close to the neck and made him wince.

As soon as their extra ammunition was exhausted and the contending forces in this respect were placed more on a footing of equality, Buck and his cronies began to give ground before the better aim and greater determination of Bob and his comrades.

"Give it to them, fellows!" shouted Bob, as the retreat of their opponents was rapidly becoming a rout.

At the moment he called out, the progress of the fight had brought the radio boys directly in front of the windows of one of the largest drygoods stores in the town.

In the light that came from the windows Bob saw a snowball coming directly for his head. He dodged, and——

Crash! There was the sound of splintering glass, and the snowy missile whizzed through the plate glass window!



CHAPTER II

IN A DILEMMA

There was a moment of stupor and paralysis as the meaning of the crash dawned upon the radio boys.

Buck and his crowd had vanished and were footing it up the fast-darkening street at the top of their speed.

The first impulse of the radio boys was to follow their example. They knew that none of them was responsible for the disaster, and they were of no mind to be sacrificed on behalf of the gang that had attacked them. And they knew that in affairs of that kind the ones on the ground were apt to suffer the more severely.

They actually started to run away, but had got only a few feet from the scene of the smash when Bob, who had been thinking quickly, called a halt.

"None of this stuff for us, fellows," he declared. "We've got to face the music. I'm not going to have a hunted feeling, even if we succeeded in getting away. We know we didn't do it and we'll tell the plain truth. If that doesn't serve, why so much the worse for us. But at any rate we won't be despising ourselves as cowards."

As usual, his comrades accorded him the leadership and fell in with his plan, although it was not without many misgivings that they awaited the coming of the angry proprietor of the place, who had already started in pursuit of them, accompanied by many others who had been attracted by the crash and whose numbers were being rapidly augmented.

"Here are the fellows that smashed my window!" cried Mr. Larsen, the proprietor of the drygoods store, rushing up to them and shaking his fist in their faces. "Where are the police?" he shouted, looking around him. "I'll have them arrested for malicious damage."

And while he faced them, gesticulating wildly, his face purple with anger and excitement, it may be well for the benefit of those who have not read the preceding volumes of this series to tell briefly who the radio boys are and what had been their adventures before the time this story opens.

The acknowledged leader of the boys was Bob Layton, son of a prosperous chemist of Clintonia, in which town Bob had been born and brought up. Mr. Layton was a respected citizen of the town and foremost in its civic activities. Clintonia was a thriving little city of about ten thousand population, situated on the Shagary River, about seventy-five miles from the city of New York.

Bob at the beginning of this story was about sixteen years old, tall and stalwart and a clean-cut specimen of upstanding American youth. He was of rather dark complexion and had a pair of eyes that looked straight at one. Those eyes were usually merry, but could flash with indignation when circumstances required it. He was never on the lookout for trouble, but was always ready to meet it half way, and his courageous character together with his vigorous physique had made him prominent in the sports of the boys of his own age. He was a crack baseball player and one of the chief factors of the high school football eleven. No one in Clintonia was held in better liking.

Bob's special chum was Joe Atwood, son of the leading physician of the town. Joe was fair in complexion and sturdy in makeup. He and Bob had been for many years almost inseparable companions, Bob usually acting as captain in anything in which they might be engaged, while Joe served as first mate. The latter had a hot temper, and his impulsiveness sometimes got him into trouble and would have involved him in scrapes oftener if it had not been for the cooler head and steadying influence of Bob.

Two other friends of the boys who were almost always in their company were Herb Fennington, whose father kept a large general store in the town, and Jimmy Plummer, son of a respected carpenter and contractor. Herb was of a rather indolent disposition, but was jolly and good-natured and always full of jokes, some of them good, others poor, which he frequently sought to spring on his companions.

Jimmy was a trifle younger than his mates, fat and round and excessively fond of the good things of life. His liking for that special dainty had gained him the nickname of "Doughnuts," and few of such nicknames were ever more fittingly bestowed.

Apart from the liking that drew them together, the boys had another link in their common interest in radio. From the time that this wonderful new science had begun to spread over the country with such amazing rapidity, they had been among the most ardent "fans." Everything that they could read or learn on the subject was devoured with avidity, and they were almost constantly at the home of one or the other, listening in on their radio sets and, lately, sending messages, in the latter of which they had now attained an unusual degree of proficiency.

In decided contrast to Bob and his friends was another group of Clintonia youth, between whom and the radio boys there was a pronounced antipathy. The leader of this group was Buck Looker, a big overgrown, hulking boy, dull in his studies and a bully in character. His two special cronies were Carl Lutz, a boy of about his own age, and Terry Mooney, both of them noted for their mean and sneaking dispositions. Buck lorded it over them, and as his father was one of the richest men in the town they cringed before him and were always ready to back him up in any piece of meanness and mischief.

The enthusiasm of Bob and his friends for radio was fostered by the help and advice of the Reverend Doctor Dale, the clergyman in charge of the Old First Church of Clintonia, who, in addition to being an eloquent preacher, was keenly interested in all latter-day developments of science, especially radio. Whenever the boys got into trouble with their sets they knew that all they had to do was to go to the genial doctor and be helped out of their perplexities.

An incident that gave a great impetus to their interest in the subject was the offering of prizes by Mr. Ferberton, the member of Congress for their district, for the best radio sets turned out by the boys of his congressional district by their own endeavors. Bob, Joe, and Jimmy entered into this competition with great zest. Herb with his habitual indolence kept out of it.

While the boys were engrossed with their radio experiments an incident happened in town that led them into many unexpected adventures. An automobile run by a visitor in town, a Miss Nellie Berwick, got out of her control and dashed through the window of a store. Bob and Joe, who happened to be at hand, rescued the girl from imminent peril, while Herb and Jimmy did good work in curbing the fire that followed the accident.

How the boys learned of the orphan girl's story, got on the track of the rascal who had tried to swindle her and forced him to make restitution; what part the radio played in bringing the fellow to terms; how they detected and thwarted the plans of Buck Looker and his cronies to wreck their sets; are told in the first volume of this series entitled: "The Radio Boys' First Wireless; Or, Winning the Ferberton Prize."

That summer the chums went to Ocean Point on the seashore, where many of the Clintonia folks had established a little bungalow colony of their own. What adventures they met with there; what strides they made in the practical work of radio; how they were enabled by their knowledge and quick application of it to save a storm-tossed ship on which members of their own families were voyaging; how they ran down and captured the scoundrel Cassey who had knocked out with a blackjack the operator at the sending station and looted his safe—these and many more incidents are narrated in the second volume of this series entitled: "The Radio Boys at Ocean Point; Or, The Message That Saved the Ship."

While the summer season was yet at its height, the boys had occasion to rescue the occupants of a rowboat that had been run down by men in a stolen motor boat. The two rescued youths proved to be vaudeville actors, and the boys grew very friendly with them. The injury that crippled one of them, Larry Bartlett; the false accusation brought against him by Buck Looker; the way in which the boys succeeded in getting work for Larry at the sending station, where his remarkable gift of mimicry received recognition; how they themselves were placed on the broadcasting program, and the clever way in which they trapped the motor-boat thieves; are told in the third volume of the series, entitled: "The Radio Boys at the Sending Station; Or, Making Good in the Wireless Room."

The coming of fall brought the boys back to Clintonia, where, however, the usual course of their studies was interrupted by an epidemic that made necessary for a time the closing of the schools. This gave the radio boys an opportunity to make a trip to Mountain Pass, a popular resort in the hills. Here they came in contact with a group of plotters who were trying to put through a nefarious deal and were able to thwart the rascals through the use of radio. By that same beneficent science too they were able to save a life when other means of communication were blocked. And not the least satisfactory feature was the utter discomfiture they were able to visit upon Buck Looker and his gang. These and many other adventures are told in the fourth volume of the series, entitled: "The Radio Boys at Mountain Pass; Or, The Midnight Call for Assistance."

And now to return to the radio boys as they stood facing the angry storekeeper amid a constantly growing throng of curious onlookers. They had been in many tighter fixes in their life but none that was more embarrassing.

"I'll have them arrested!" the storekeeper repeated, his voice rising to a shrill treble.

"Now look here," replied Bob. "Suppose you cut out this talk of having us arrested. In the first place, we didn't break your window. In the second place, if we had it wouldn't be a matter of arrest but of making good the damage."

"All right then," said Mr. Larsen eagerly, catching at the last word. "Make good the damage. It will cost at least two hundred dollars to replace that window."

"I think you're a little high," returned Bob. "But that doesn't matter. I didn't say that we'd make the damage good. I said that if we'd broken it, it would be a matter of making good. But we didn't break it, and that lets us out I'll say."

"It's easy to say that," sneered the merchant. "How do I know that you didn't break it? It would of course be natural for you to try to lie out of it."

"It wouldn't be natural for us to lie out of it," replied Bob, controlling his temper with difficulty. "That isn't our way of doing things. Why do you suppose we stayed here when it would have been perfectly easy for us to get away? It wasn't a snowball we threw that broke your window. It was one thrown by the fellows we were fighting with."

"Always the other fellow that does it!" replied the storekeeper angrily. "Who was that other fellow or fellows then? Tell me that. Come on now, tell me that."

Bob kept silent. He had no love for Buck Looker and his gang, who had always tried to injure him, but he was not going to inform.

"See," said Mr. Larsen, misunderstanding his silence. "When I ask you, you can't tell me. You're the fellows that did it, all right, and you'll pay me for it or I'll have you put in jail, that's what I'll do."

"I saw the fellows who were firing snowballs in this direction," spoke up Mr. Talley, a caterer, pushing his way through the throng. "I nearly bumped into them as they were running away. Buck Looker was one of them. I saw his face plainly and can't be mistaken. The others I'm not so sure of, but I think they were Carl Lutz and Terry Mooney.

"For my part, Mr. Larsen," he continued, "I don't see how a snowball could break that heavy plate-glass window, anyway. My windows are no heavier, and they've often had snowballs come against them without doing any harm. Are you sure it wasn't something else that smashed the glass?"

"Dead sure," replied Larsen. "Come inside and see for yourself."

He led the way into his store, and Mr. Talley, the boys, and a number of others crowded in after him.

"Look," said Larsen, pointing to a piece of dress goods that had been hanging in the window. "See where the snow has splashed against it? There's no question that a snowball did it. You can see the bits of snow around here yet if you'll only look."

This was true and the evidence seemed conclusive. But just then Bob's keen eyes detected something else. He stooped down and brought up quite a large sharp-edged stone which still had some fragments of snow adhering to it and held it up for all to see.

"Here's the answer," he said. "This stone was packed in the snowball, and that is why it smashed the window!"



CHAPTER III

THE STUTTERING VOICE

There was a stir of interest and exclamations of surprise as those in the store crowded closer to get a better view.

"That explains it," said Mr. Talley, as he examined the missile. "I was sure that no mere ball of snow could break that heavy window. To put such a stone in a snowball was little less than criminal," he went on gravely. "If that had hit any one on the temple it would almost certainly have killed him."

"It was coming straight for my head when I dodged," said Bob.

"That's another proof that it wasn't any ball we threw that broke the window," put in Joe. "Each one of us is willing to swear that there was no stone in any ball that we threw."

"Not only then but at any time," put in Herb. "Only a mean coward would do a thing like that. None of us has done it any time in his life."

"I believe that," replied Mr. Talley. "I've known all you boys ever since you were little kids and I know you wouldn't be capable of it."

"That's all very well," said Mr. Larsen. "But that doesn't pay for my window. Whether any of you boys threw the ball or not you can't deny that you were engaged in a snowball fight right in front of my windows. If the fight hadn't been going on the window wouldn't have been smashed."

There was a certain amount of justice in this, and the boys were fair enough to acknowledge it.

"I suppose you are right there, Mr. Larsen," said Bob regretfully. "We ought to have kept out of range of the windows, but in the excitement we forgot all about that. Then, too, we never would have supposed that any ordinary snowball would have broken the window. Perhaps that was in the back of our minds, if we thought of it at all."

"Is the window insured?" queried Mr. Talley.

"Yes, it is," answered the storekeeper.

"Well, then, that lets you out," remarked Mr. Talley, with a note of relief in his voice. "That puts the matter up to the insurance company. If they want to take any legal steps they can; and of course they ought to be compensated by the parents of the boy who may be found guilty of having thrown the ball with a stone in it. For my part, I doubt very much that it can ever be proved, unless the boy himself owns up to it."

"Think of Buck Looker ever owning up to anything!" muttered Jimmy.

"As for these boys," continued Mr. Talley, "I am perfectly sure in my own mind that they are telling the truth. You'll have to look for the culprit in the other crowd, and I've already told you who they are, or who one of them is, at least."

"Well," said the storekeeper, who by this time had cooled down considerably, "that, I suppose, will be something for the insurance company to settle. But by the terms of my contract with them I'll have to help them all I can to find out the responsible party, and I'll have to give them the names of all the boys concerned in the fight."

"That's all right," responded Bob. "You know our folks and you know that they're good for any judgment that may be found against them. But I'm sure it will be somebody else that will have to pay the bill."

There was nothing more to be done for the present, and the boys filed out of the store, after having expressed their thanks to Mr. Talley for the way he had championed their cause.

"Gee!" murmured Joe, as they went up the street toward their homes, "I know how a fellow feels now after he's been put through the third degree."

"It was rather a hot session," agreed Bob. "But I'm glad we had it out with him instead of running away. It's always best to take the bull by the horns. And you can't blame Mr. Larsen for feeling sore about it. Any one of us would probably have felt the same way."

"Sure thing," admitted Herb. "But think of that dirty trick of Buck Looker in putting stones in snowballs! It wasn't only that one that went through the window. Every time I got hit it made me jump."

"Same here," said Jimmy. "I was thinking all the time that they were the hardest snowballs I ever felt, but it never came into my mind that there were stones in them."

"Trust Buck to be up to every mean trick that any one ever thought of," returned Bob. "He hasn't got over the way we showed him up at Mountain Pass. He thought he had us dead to rights in the matter of that burned cottage, and it made him wild to see the way we came out on top. He and his gang would do anything to get even."

"It will be interesting to see what he'll say when this matter of the window is put up to him and his pals," remarked Herb.

"Not a doubt in the world what he'll say," replied Joe. "He'll swear till he's blue in the face that he never dreamed of using a stone in the snowballs. Do you remember how he told us that he'd lie in court to keep us from putting anything over on him? Any one that expects to get the truth out of Buck is barking up the wrong tree. I guess the insurance company would better kiss their money good-by."

"I'm afraid so," returned Bob. "It was dark and there probably weren't any witnesses who saw them put the stones in, and it is likely that the company will have to let the matter drop."

The lads had reached Bob's gate by this time, and they separated with a promise to come over and listen in on the radio later on.

Bob told the whole story to his parents at the supper table that night, and his father and mother listened with great interest and some concern.

"I'm sorry you were mixed up in the thing at all, Bob," his father remarked thoughtfully. "Being in it, however, you acted just as you should have done. Just how far you and your friends may be held responsible, in case they can't find the one who actually threw the ball that broke the window, I'm not lawyer enough to say. It's barely possible that there may be some ground for action on the score of culpable carelessness in taking part in a snowball fight in front of store windows, and of course you were wrong in doing that. But the total amount involved is not very great after all, and it would be divided up among the parents of the four of you, so there's nothing much to worry about. It would gall me though to have to pay for damages that were really caused by that cub of Looker's."

"I'm sorry, Dad," said Bob. "I'm hoping yet that something may develop that will put the thing up to Buck, or whoever it was of his gang that actually threw the ball."

"Let's hope so," returned Mr. Layton, though without much conviction in his voice, and dismissed the subject.

A little while afterward the other three boys came over to Bob's house to listen in on the radio concert. So much time, however, had been taken up in discussing the afternoon's adventure that they missed Larry's offering, which was among the first on the program. This was a keen disappointment, which was tempered, however, by the probability that they could hear him some evening later in the week.

"Sorry," remarked Joe. "But it only means that we still have a treat in store when the old boy begins to roar and growl and hiss so as to make us think that a whole menagerie has broken loose and is chasing us. In the meantime we can fix up that aerial so as to get a little better results."

"Funny thing I noticed the other day," remarked Bob, as they embarked upon some experiments.

"All sorts of funny things in the radio game," observed Joe. "Something new turns up every day. Things in your set that you think you can't do without you find you can do without and get results just about as usual."

"Just what I was going to tell you," returned Bob. "You must be something of a prophet."

"Oh, I wouldn't go quite so far as to say that," replied Joe, with mock modesty.

"Isn't he the shrinking violet?" chaffed Jimmy.

"Stop your kidding, you boobs, and let a regular fellow talk," chided Bob. "What I was going to say was that while I was tinkering with the set I disconnected the ground wire. Of course I thought that would put the receiver out of business for the time, and I was almost knocked silly when I found that I could hear the concert that was going on just about as well as though the wire had been connected. How do you account for that?"

"Don't account for it at all," replied Herb. "Probably just a freak, and might not happen again in a thousand times. Likely it was one of the unexplainable things that happen once in a while. Maybe there was a ground connection of some kind, if not by the wire. I wouldn't bank on it."

"It's queer, too, how many kinds of things can be used as aerials," put in Joe. "I heard the other day of a man in an apartment house where the owner objected to aerials, who used the clothesline for that purpose. The wire ran through the rope, which covered it so that it couldn't be seen. It didn't prevent its use as a clothesline either, for he could hear perfectly when the wash was hanging on it."

"Oh, almost anything will do as an aerial," chimed in Jimmy. "The rib of an umbrella, the rainspout at the side of the house, the springs of a bed give good results. And that's one of the mighty good things about radio. People that have to count the pennies don't have to buy a lot of expensive materials. They can put a set together with almost any old thing that happens to be knocking around the house."

Bob had been working steadily, and, as the room was warm, his hands were moist with perspiration. He had unhooked an insulated copper wire that led to his outside aerial. His head phones were on, as he had been listening to the radio concert while he worked.

"I'll have to miss the rest of that selection, I guess," he remarked regretfully, as he unhooked the wire. "It's a pity, too, for that's one of the finest violin solos I ever heard. Great Scott! What does that mean?"

The ejaculation was wrenched from him by the fact that although he had disconnected the wire he still heard the music—a little fainter than before but still with every note distinct.

He could scarcely believe his ears and looked at his friends in great bewilderment.

"What's the matter?" asked Joe, jumping to his feet. "Get a shock?"

"Not in the sense you mean, but in another way, yes," replied Bob, still holding the exposed end of the copper wire in his fingers. "What do you think of that, fellows? I'm an aerial!"

"Come out of your trance," adjured Herb unbelievingly. "They talk that way in the insane asylums."

"Clap on your headphones," cried Bob, too intent on his discovery to pay any attention to the gibe.

They did so, and were amazed at hearing the selection as plainly as did Bob himself.

The latter had been holding the disconnected wire so that his fingers just touched the uncovered copper portion at the end. Now he hastily scraped off several inches of the insulation and grasped the copper wire with his hand. Instantly the volume of sound grew perceptibly greater.

Hardly knowing what to make of it, he scraped off still more of the insulation.

"Here, you fellows," he shouted. "Each of you take hold of this."

Joe was the first to respond, and the sound became louder. Then Herb and Jimmy followed suit, and it was evident that they served as amplifiers, for with each additional hand the music swelled to greater volume.

The boys looked at each other as if asking whether this was all real or if they had suddenly been transferred to some realm of fancy. They would not have been greatly surprised to wake up suddenly and find that they had been dreaming.

But there was no delusion about it and they listened without saying another word until, in a glorious strain of melody, the selection came to an end. Nor did they break the silence until a band orchestra was announced and crashed into a brilliant overture.

While it was still in full swing, Bob had an inspiration. He took off his headphones and clamped them on to the phonograph that stood on a table near by. Instantly the music became intensified and filled the room. When all their hands were on the wire, it became so loud that they had to close the doors of the phonograph.

"Well," gasped Bob, when the last strain had died away and the demonstration was complete, "that's something new on me."

"Never dreamed of anything like it," said Joe, sinking back in his chair. "Of course we know that the human body has electrical capacity and that operators sometimes have to use metal shields to protect the tube from the influence of the hand. And in our loop aerial at Ocean Point you noticed that the receptivity of the tube was modified when we touched it with our fingers."

"Of course, in theory," observed Bob thoughtfully, "the human body possesses inductance as well as capacity, and so might serve as an antenna. But I never thought of demonstrating it in practice."

"So Bob is an aerial," grinned Herb. "I always knew he was a 'live wire,' but I never figured him out as an antenna."

"And don't forget that if Bob is an aerial we're amplifiers," put in Jimmy.

"There's glory enough for all," laughed Joe. "We'll have to tell Doctor Dale and Frank Brandon about this. We've got so many tips from them that it's about time we made it the other way around."

They were so excited about this new development which they had stumbled upon purely through accident that they sat talking about it for a long time until Bob chanced to look at his watch.

"Just have time for the last selection," he remarked, as he reconnected the aerial. "We'll wind up in the regular way this time. It's an aria from Lucia and I don't want to miss it."

He had some difficulty in making his adjustment, as there was a lot of interference at the moment.

"Raft of amateurs horning in," he muttered. "All of them seem to have chosen just this time to do it. I wonder——"

He stopped as though he had been shot, and listened intently. Then he beckoned to the others to adjust their headphones.

Into the receiver was coming a succession of stuttering sounds that eventually succeeded in framing intelligible words. Ordinarily this might have provoked laughter, but not now. They had heard that voice before.

It was the voice of Dan Cassey!



CHAPTER IV

A PUZZLING MYSTERY

For the second time that evening the radio boys thought they must be dreaming.

Cassey! Cassey the swindler, whom they had compelled to make restitution to the victim he had wronged. Cassey the thug, whom they had captured in that wild chase after he had looted the safe and nearly killed the operator in the sending station. Cassey the convict, who, to their certain knowledge, had been sentenced to a long term in prison.

What was Cassey doing over the radio? That it was that scoundrel they had no doubt. The stuttering, the tones of the voice, the occasional whistle which he indulged in in order to go on—all these things they recognized perfectly. It was the wildest kind of improbability that he had a double anywhere who could reproduce him so perfectly.

Gone now was any thought of the aria from Lucia. Bob motioned frantically to Jimmy to hand him a pencil and a sheet of paper. Then he jotted down the words, as after great efforts they fell one by one from the stutterer's lips. As Bob did this he bent over the paper in frowning perplexity. The words themselves were intelligible, but they did not seem to make sense, nor was there anywhere a connected sentence.

Finally the stammering voice ceased, and after they had waited several minutes longer to make sure that it would not resume, the boys took off their headphones and gazed at each other in utter bewilderment.

"Well, I'll be blessed!" exclaimed Joe. "That villain Cassey, of all men on the face of the earth! What do you make of it, Bob?"

"I don't know what to make of it," confessed Bob. "It has simply knocked me endways. I never thought to hear of that rascal again for the rest of my life. Yet here he is, less than a year after he's been sentenced, talking over the radio."

"Perhaps he's received a pardon," hazarded Jimmy.

"Not at all likely," answered Bob. "It isn't as though he were a first offender. He's old in crime. You remember the raking over the judge gave him when he sentenced him. Told him if he had it in his power he'd give him more than he actually did. No, I think we can dismiss that idea."

"Isn't it possible," suggested Herb, "that he's employed as radio operator in the prison? He understands sending and receiving all right."

"That doesn't strike me hard either," Bob objected. "Likely enough the prison is equipped with a wireless set, but it isn't probable that they'd let a prisoner operate it. It would give him too good a chance to get in touch with confederates outside the jail. Then, too, his stuttering would make him a laughing stock.

"The only explanation that I can see," he went on, "is that he's escaped, and he's sending this message on his own hook. Though what the message is about is beyond me."

"Just what did you get down?" asked Jimmy curiously. "I caught a few words, but I don't remember them all."

"It's a regular hodgepodge," replied Bob, spreading out the sheet of paper, while they all crowded around to read.

"Corn—hay—six—paint—water—slow—sick—jelly," read Joe aloud. "Sounds to me like the ravings of a delirium patient."

"And yet I'm sure that I got all the words down right," said Bob perplexedly. "It must be a code of some kind. We can't understand it, and Cassey didn't mean that any one should except some one person whose ear was glued to a radiophone. But you can bet that that person understood it all right."

"I wonder if we couldn't make it out," suggested Herb.

"No harm in trying," said Joe, "though compared to this a Chinese puzzle is as simple as A B C. Let's take a hack at it, anyhow. We'll each take a separate sheet of paper and try to get something out of it that makes sense."

For nearly an hour the boys did their best. They put the words in different orders, read them forward and backward. But the ideas conveyed by the separate words were so utterly dissimilar that they could frame nothing that had the slightest glimmering of sense and they were finally compelled to give it up.

"If time were money, we'd spend enough on this stuff to make us bankrupt," Joe remarked, in vast disgust, as he rose to get his cap. "Dan Cassey was foxy when he made this up. We'll have to give the rascal credit for that."

"Yes," admitted Herb, "it's the best kind of a code. Any one of those words might mean any one of a hundred thousand things. A man might spend a lifetime on it and be no nearer success at the end than he was when he started. The only way it can be unraveled is by finding the key that tells what the words stand for. And even that may not exist in written form. The fellows may simply have committed them to memory.

"I'll tell you what I'll do!" Bob exclaimed. "I'll get the prison to-morrow on the long distance 'phone and ask them about Cassey. I'll tell them all about this radio message, and it may be a valuable tip to them. They may be able to locate the station from which the messages come, if there are any more of them. You remember how Mr. Brandon located Cassey's sending station the first time."

Bob was as good as his word, and got in communication with the prison just before school time. The warden was gruff and inclined to be uncommunicative at first, but his manner changed remarkably after he heard of the radio message and he inquired eagerly for the slightest details.

"Yes, Cassey has escaped," he told Bob. "He got away about two months ago. He had behaved himself well for the first six months of his imprisonment, and we made him a trusty. In that capacity he had access to various parts of the prison and occasionally to my own quarters, which are in a wing connected with the prison. In some way that hasn't yet been discovered he got possession of clothes to cover his prison uniform and got away one day from the yard in which he was working. Probably with his help, two others got away at the same time. Their names are Jake Raff and Toppy Gillen, both of them desperate criminals and in for long terms. Likely enough the three of them are operating together somewhere. We made a careful search for them and have sent out descriptions of them to the police of all the important cities in the United States. But this clue of yours is the only one we have, and it may prove a most important one. I'll see that the Federal radio authorities are notified at once. Keep in touch with me and let me know if you come across anything else that seems to point to Cassey. His escape is a sore point with me, and I'd be glad to have him once more behind the bars. You can be sure he'll never get away again until he's served out the last day of his sentence."

With a warm expression of thanks the warden hung up his telephone receiver, and Bob hurried off to school to tell his comrades of what he had learned.

There was no chance for this, however, before recess, as he had been kept so long at the telephone that he was barely able to reach the school before the bell rang.

When at last he told them of his talk with the warden, they listened with spellbound interest.

"So the villain managed to escape, did he?" ruminated Joe. "That's a black mark against the warden, and it's no wonder he's anxious to get him back. I'd hate to be in Cassey's shoes if the prison gates ever close on him again."

"You'd think it would be a comparatively easy matter to capture him," suggested Herb. "The fact that he stutters so badly makes him a marked man."

"You can bet that he doesn't do any more talking than he can help," replied Joe. "And, for that matter, I suppose there are a good many thousand stutterers in the United States. Almost every town has one or more. Of course it's against him, but it doesn't by any means make it a sure thing that he'll be nabbed."

Buck Looker and his cronies happened to pass them in the yard just at that moment and caught the last word. Buck whispered something to Carl Lutz, and the latter broke out into uproarious laughter.

It was so obviously directed against Joe that his impulsive temper took fire at once. He stepped up to the trio, despite Bob's outstretched hand that tried to restrain him.

"Were you fellows laughing at me?" he asked of the three, though his eyes were fastened directly on Buck's.

"Not especially at you," returned Buck insolently. "But at something you said."

"And what was that?" asked Joe, coming a step nearer, at which Buck stepped back a trifle.

"About getting nabbed," he said. "It made me think of some fellows I know that were nabbed last night for breaking windows."

"Oh, that was it!" remarked Joe, with dangerous calmness while his fist clenched. "Now let me tell you what it reminds me of. It makes me think of three cowards who smashed a window last night with a stone packed in a snowball and then ran away as fast as their legs could carry them. Perhaps you'd like me to tell you their names?"

"I don't know what you're talking about," retorted Buck, changing color.

"Oh, yes, you do," replied Joe. "And while I'm about it, I'll add that the fellows who smashed the window were not only cowards, but worse. And their names are Buck Looker, Carl Lutz and Terry Mooney."

"What's that?" cried Buck, bristling up, while an angry growl arose from his cronies.

"You heard me the first time," replied Joe; "but to get it into your thick heads I'll say it again. The cowards, and worse, I referred to are named Buck Looker, Carl Lutz and Terry Mooney."



CHAPTER V

MARVELS OF WIRELESS

"That's fighting talk," blustered Buck, as he made a pretense of getting ready to throw off his coat.

"That's precisely what I want it to be," declared Joe, as he tore off his coat and threw it to the ground.

By this time most of the boys in the school yard had sensed the tenseness of the situation and had gathered around Joe and Buck, forming a ring many lines deep.

"A fight!" was the cry.

"Go in, Joe!"

"Soak him, Buck!"

Before Joe's determined attitude and flashing eyes, Buck wavered. He fingered his coat uncertainly and glanced toward the school windows.

"There's one of the teachers looking out," he declared. "And it's against the rules to fight on the school grounds. If it wasn't for that I'd beat you up."

There was a general snicker from the boys at Buck Looker's sudden regard for the rules of the school.

"Any other place you can think of where you'd like to beat me up?" said Joe sarcastically. "How about this afternoon after school down by the river?"

"I——I've got to go out of town this afternoon," Buck stammered. "But don't you worry. I'll give you all the fight you're looking for the first chance I get."

Murmurs of derision arose from the crowd, and the flush on the bully's sour face grew much deeper.

"You're just a yellow dog, Buck!" exclaimed Joe, in disgust. "Have I got to pull your nose to make you stand up to me?"

He advanced toward him, and Buck retreated. What would have happened next will never be known, for just at that moment one of the teachers emerged from the school and came toward the ring. Hostilities at the moment were out of the question, and the boys began to scatter. Buck heaved a sigh of evident relief, and now that he felt himself safe, all his old bluster came back to him.

"It's mighty lucky for you that Bixby came out just then," he declared. "I was just getting ready to thrash you within an inch of your life."

Joe laughed sarcastically.

"The trouble with you, Buck, is that you spend so much time getting ready that you never have any time for real fighting," he remarked. "It took you an awfully long time to get your coat unbuttoned."

"They laugh best who laugh last," growled Buck. "And don't forget that you fellows have got to pay for that glass you broke."

"You've got another guess coming," replied Joe. "You or one of your gang broke that glass and we can prove it."

"I wasn't downtown that night at all," said Buck glibly.

"Don't add any more lies to your score," said Joe scornfully. "We've got you! You and your gang are the only fellows in town who would put stones in snowballs, anyway."

"If that's all the evidence you've got, it wouldn't go far in a court of law," sneered Buck. "Any judge would see that you were trying to back out of it by putting it up to somebody else."

"Perhaps you don't know that Mr. Talley bumped into you while you were running away," remarked Joe.

This shot told, for Buck had banked on the darkness and had forgotten all about his encounter with Mr. Talley. He had been nursing the comfortable assurance that all he had to do was to deny. Now his house of cards had come tumbling about his ears. Mr. Talley was a respected citizen, and his word would be accepted by everybody.

Joe saw the effect of his remark and smiled drily.

"Want to revise that statement of yours that you weren't downtown at all last night?" he asked, with affected politeness.

"He—he was mistaken," stammered Buck weakly, as he walked away, followed by his discomfited cronies.

"I guess that will hold him for a while," chuckled Jimmy, as the radio boys watched his retreating figure.

Two or three days passed without special developments. The broken pane of glass had been restored and the parents of the boys had been formally notified by the insurance company that they would be held responsible jointly for the damages. A similar notice had been sent to the fathers of Buck and his mates.

Mr. Looker replied, denying that his son was at all implicated in the matter and refusing to pay. Mr. Layton admitted that his son had been throwing snowballs in front of the store on the night in question, but he stated that he had not thrown the ball with a stone in it that broke the window. He added that any further communication regarding the matter could be sent to his lawyer.

Of the others involved, some had taken similar positions and others had ignored the matter altogether, leaving it to the insurance company to make the next move. And there for the time the matter rested.

The radio boys had missed Larry's performance on the night that he had opened with his new repertoire, but they were bound not to be cheated of the second, which took place only a few nights later.

They crowded eagerly about the radio set when their friend's turn was announced, and listened with a breathless interest, that was intensified by their warm personal regard for the performer, to the rendition of the cries of various animals with which Larry regaled them.

The imitations were so lifelike that the boys might well have imagined they were in a zoological garden. Lions, tigers, bears, elephants, snakes, moose, and other specimens of the animal and the reptile tribes were imitated with a fidelity that was amazing. In addition, the renditions were interspersed with droll and lively comments by Larry that added immensely to the humor of the performance. When at last it was over, the boys broke out into enthusiastic hand-clapping that would have warmed Larry's heart, had he been able to hear it.

"The old boy is all there!" chortled Bob enthusiastically.

"He's a wonder!" ejaculated Joe. "No question there of a square peg in a round hole. He's found exactly the work in life he's specially fitted for."

"And think of the audience he has," put in Jimmy. "At this very minute there are probably hundreds of thousands of people who have been tickled to death at his performance. Just suppose those people all clapped their hands at once just as we have done and we could hear it. Why, it would be like a young earthquake."

At this moment the doorbell rang, and Dr. Dale was announced. He spent a few minutes with Mr. and Mrs. Layton, and then came up to have a little chat with the boys. This was one thing he never overlooked. His interest in and sympathy with the young were unbounded, and accounted largely for the influence that he exerted in the community.

The radio boys greeted the minister warmly and gladly made room for him around the table. His coming was never felt by them to be an interruption. They regarded him almost as one of themselves. Apart, too, from the thorough liking they had for him as a man, they were exceedingly grateful to him for the help he had been to them in radio matters. He was their mentor, guide and friend.

"I knew I'd find you busy with the radio," he said, with a genial smile.

"We can't be torn away from it," replied Bob. "We think it's just the greatest thing that ever happened. Just now we've been listening to Larry Bartlett give his imitations of animals. You remember Larry?"

"I certainly do," replied Dr. Dale. "And I remember how you boys helped him get his present position. It was one of the best things you ever did. He's certainly a finished artist. I heard him on his opening night, and I've laughed thinking of it many times since. He's a most amusing entertainer."

It was the first opportunity the boys had had to tell the doctor of the night when Bob found that he was a human aerial, and he listened to the many details of the experiment with absorbed interest.

"It's something new to me," he said. "You boys have reason to be gratified at having had a novel experience. That's the beauty of radio. Something new is always cropping up. Many of the other sciences have been more or less fully explored, and while none of them will ever be exhausted, their limits have been to some extent indicated. But in radio we're standing just on the threshold of a science whose infinite possibilities have not even been guessed. One discovery crowds so closely on the heels of another that we have all we can do to keep track of them.

"I've just got back from a little trip up in New York State," he went on, as he settled himself more comfortably in his chair, "and I stopped off at Schenectady to look over the big radio station there. By great good luck, Marconi happened to be there on the same day——"

"Marconi!" breathed Bob. "The father of wireless!"

"Yes," smiled Dr. Dale. "Or if you want to put it in another way, the Christopher Columbus who discovered the New World of radio. I counted it a special privilege to get a glimpse of him. But what attracted my special attention in the little while I could spend there was a small tube about eighteen inches long and two inches in diameter which many radio experts think will completely revolutionize long distance radio communication."

"You mean the Langmuir tube," said Joe. "I was reading of it the other day, and it seems to be a dandy."

"It's a wonderful thing," replied the doctor. "Likely enough it will take the place of the great transatlantic plants which require so much room and such enormous machinery. It's practically noiseless. Direct current is sent into the wire through a complicated wire system and generates a high frequency current of tremendous power. I saw it working when it was connected with an apparatus carrying about fifteen thousand volts of electricity in a direct current. A small blue flame shot through the tube with scarcely a particle of noise. The broken impulse from the electrical generators behind the tube was sent through the tube to be flung off from the antenna into space in the dots and dashes of the international code. That little tube was not much bigger than a stick of dynamite, but was infinitely more powerful. I was so fascinated by it and all that it meant that it was hard work to tear myself away from it. It marks a great step forward in the field of radio."

"It must have been wonderfully interesting," remarked Bob. "And yet I suppose that in a year or two something new will be invented that will put even that out of date."

"It's practically certain that there will be," assented the doctor. "The miracles of to-day become the commonplaces of to-morrow. That fifty-kilowatt tube that develops twelve horsepower within its narrow walls of glass, wonderful as it is, is bound to be superseded by something better, and the inventor himself would be the first one to admit it. Some of the finest scientific brains in the country are working on the problem, and he would be a bold prophet and probably a false prophet that would set any bounds to its possibilities.

"Radio is yet in its infancy," the doctor concluded, as he rose to go. "But one thing is certain. In the lifetime of those who witnessed its birth it will become a giant—but a benevolent giant who, instead of destroying will re-create our civilization."



CHAPTER VI

THE FOREST RANGER

Some days later Bob and Herb and Joe were on their way to Bob's house to do a little experimenting on the latter's set, when they were surprised at the alacrity with which Jimmy turned a corner and came puffing up to them.

"Say, fellows!" he yelled, as he came within earshot, "I've got some mighty interesting news for you."

"Let's have it," said Bob.

"It's about the snowball Buck fired through the window," panted Jimmy, falling into step beside them. "I met a man who's staying up at the Sterling House. He says Buck's the boy who did it, all right."

"How does he know?" all of the others asked with interest.

"Saw Buck pick up a stone and pack the snow hard around it," said Jimmy importantly. "He saw it himself, so we've got one witness for our side, all right."

"That's good," said Bob, adding, with a glint in his eye: "Say, wouldn't I like to get my hands on Buck, just for about five minutes!"

"Well, you won't have a chance," said Jimmy, enjoying being the bearer of so much news. "Buck's gone with his father to a lumber camp up in Braxton woods."

"How do you know all this?" inquired Herb curiously. "You seem to be chock full of information to-day."

"Oh, a little bird told me," said Jimmy, looking mysterious. However, as Herb made a threatening motion toward him, he hurried to explain. "I met Terry Mooney," he said. "I told him I knew all about who put the stone in the snowball and I told him that our crowd was going to make his look like two cents. He laughed and said swell chance we'd have. Said Buck had gone to the lumber camp with his father and that he and Carl Lutz were going to join him in a day or two. Just like Buck to run away when he knows there's a good licking coming to him!" added Jimmy, with a sneer.

"Oh, well, what do we care?" said Joe. "At least we sha'n't have those fellows around spoiling all the fun."

"I'm glad you found out about the snowball just the same," said Bob thoughtfully. "Every little bit helps when we have to fight against that crooked gang of Buck's."

"Here's hoping," said Herb fervently, "that they stay away all the rest of the spring."

By this time the lads had reached Bob's house. It was Saturday afternoon, and as the boys crowded noisily into the hall Bob noticed that his father was in the library and that he seemed to have company.

He was starting upstairs with the other lads when his father came out of the library and called to him.

"Come on in for a few minutes, boys," he said. "I have a friend here who is a man after your own hearts," and his eyes twinkled. "He's interested in radio."

The boys needed no second invitation, for they never missed an opportunity of meeting any one who could tell them something about the wonders of radio.

Mr. Layton's guest was lounging in one of the great chairs in the library, and from the moment the boys laid eyes on him they knew they were going to hear something of more than usual interest.

The stranger was big, over six feet, and his face and hands were like a Cuban's, they were so dark. Even his fair hair seemed to have been burnt a darker hue by the sun. There was a tang of the great out-of-doors about him, a hint of open spaces and adventure that fascinated the radio boys.

"This is my son, Mr. Bentley," said Mr. Layton to the lounging stranger, still with a twinkle in his eye. "And the other boys are his inseparable companions. Also I think they are almost as crazy about radio as you are."

The stranger laughed and turned to Bob.

"I've been upstairs to see your set," he said, adding heartily: "It's fine. I've seldom seen better amateur equipment."

If Bob had liked this stranger before, it was nothing to what he felt for him now. To the radio boys, if any one praised their radio sets, this person, no matter who it was, promptly became their friend for life.

"I'm glad you think it's pretty good," Bob said modestly. "We fellows have surely worked hard enough over it."

"This gentleman here," said Mr. Layton to the boys, "ought to know quite a bit about radio. He operates an airplane in the service of our Government Forestry."

"In the United States Forest Service?" cried Bob, breathlessly, eyeing the stranger with increasing interest. "And is your airplane equipped with radio?"

"Very much so," replied Mr. Bentley. "It seems almost a fairy tale—what radio has done for the Forest Service."

"I've read a lot about the fighting of forest fires," broke in Joe eagerly. "But I didn't know radio had anything to do with it."

"It hadn't until the last few years," the visitor answered, adding, with a laugh: "But now it's pretty near the whole service!"

"Won't you tell us something about what you do?" asked Bob.

Mr. Bentley waved a deprecating hand while Mr. Layton leaned back in his chair with the air of one who is enjoying himself.

"It isn't so much what I do," protested this interesting newcomer, while the boys hung upon his every word. "It is what radio has done in the fighting of forest fires that is the marvelous, the almost unbelievable, thing. The man who first conceived the idea of bringing radio into the wilderness had to meet and overcome the same discouragements that fall to the lot of every pioneer.

"The government declared that the cost of carrying and setting up the radio apparatus would be greater than the loss occasioned every season by the terribly destructive forest fires. But there was a fellow named Adams who thought he knew better."

"Adams!" repeated Bob breathlessly. "Wasn't he the fellow who had charge of the Mud Creek ranger station at Montana?"

The visitor nodded and gazed at Bob with interest. "How did you know?" he asked.

"Oh, I read something about him a while ago," answered Bob vaguely. He was chiefly interested in having Mr. Bentley go on.

"I should think," said Herb, "that it would be pretty hard work carrying delicate radio apparatus into the lumber country."

"You bet your life it is," replied Mr. Bentley. "The only way the apparatus can be carried is by means of pack horses, and as each horse can't carry more than a hundred and fifty pounds you see it takes quite a few of the animals to lug even an ordinary amount of apparatus.

"The hardest part of the whole thing," he went on, warming to his recital as the boys were so evidently interested, "was packing the cumbersome storage batteries. These batteries were often lost in transit, too. If a pack horse happened to slip from the trail, its pack became loosened and went tumbling down the mountain side——"

"That's the life!" interrupted Jimmy gleefully, and the visitor smiled at him.

"You might not think so if you happened to be the one detailed to travel back over the almost impassable trails for the missing apparatus," observed Mr. Bentley ruefully. "It wasn't all fun, that pioneer installation of radio. Not by any means."

"But radio turned the trick just the same," said Bob slangily. "I've read that a message that used to take two days to pass between ranger stations can be sent now in a few seconds."

"Right!" exclaimed Mr. Bentley, his eyes glinting. "In a little while the saving in the cost of forest fires will more than pay for the installation of radio. We nose out a fire and send word by wireless to the nearest station, before the fire fairly knows it's started."

"But just what is it that you do?" asked Joe, with flattering eagerness.

"I do scout work," was the reply. "I help patrol the fire line in cases of bad fires. The men fighting the fire generally carry a portable receiving apparatus along with them, and by that means, I, in my airplane, can report the progress of a fire and direct the distribution of the men."

"It must be exciting work," said Herb enviously. "That's just the kind of life I'd like—plenty of adventure, something doing every minute."

"There's usually plenty doing," agreed Mr. Bentley, with a likable grin. "We can't complain that our life is slow."

"I should think," said Bob slowly, "that it might be dangerous, installing sets right there in the heavy timber."

"That's what lots of radio engineers thought also," agreed Mr. Bentley. "But no such trouble has developed so far, and I guess it isn't likely to now."

"Didn't they have some trouble in getting power enough for their sets?" asked Joe, with interest.

"Yes, that was a serious drawback in the beginning," came the answer. "They had to design a special equipment—a sort of gasoline charging plant. In this way they were able to secure enough power for the charging of the storage batteries."

Bob drew a long breath.

"Wouldn't I have liked to be the one to fit up that first wireless station!" he cried enthusiastically. "Just think how that Mr. Adams must have felt when he received his first message through the air."

"It wasn't all fun," the interesting visitor reminded the boys. "The station was of the crudest sort, you know. The first operator had a box to sit on and another box served as the support for his apparatus."

"So much the better," retorted Bob stoutly. "A radio fan doesn't know or care, half the time, what he's sitting on."

"Which proves," said Mr. Bentley, laughing, "that you are a real one!" And at this all the lads grinned.

"But say," interrupted Joe, going back to the problem of power, "weren't the engineers able to think up something to take the place of the gasoline charging stations?"

"Oh, yes. But not without a good deal of experimenting. Now they are using two hundred and seventy number two Burgess dry batteries. These, connecting in series, secure the required three hundred and fifty-volt plate current."



CHAPTER VII

RADIO AND THE FIRE FIEND

"Well, I hope that the boys know what you're talking about," interrupted Mr. Layton at this point, his eyes twinkling, "for I'm sure I don't."

"They know what I'm talking about all right," returned his guest, admiration in his laughing eyes as he looked at the boys. "Unless I miss my guess, these fellows are the stuff of which radio experts are made. I bet they'll do great things yet."

"Won't you tell us more about your experiences?" begged Herb, while the other boys tried not to look too pleased at the praise. "It isn't often we have a chance to hear of adventures like yours first hand."

"Well," said Mr. Bentley, modestly, "I don't know that there's much to tell. All we scouts do is to patrol the country and watch for fires. Of course, in case of a big fire, our duties are more exciting. I remember one fire," he leaned back in his chair reminiscently and the boys listened eagerly, hanging on every word. "It was a beauty of its kind, covering pretty nearly fourteen miles. Thousands of dollars' worth of valuable timber was menaced. It looked for a time as if it would get the better of us, at that.

"Men were scarce and there was a high wind to urge the fire on. A receiving set was rushed to the fire line, some of the apparatus in a truck and some carried by truck horses. My plane was detailed to patrol the fire line and give directions to the men who were fighting the fire."

He paused, and the boys waited impatiently for him to go on.

"The good old plane was equipped for both sending and receiving, and I tell you we patrolled that fourteen miles of flaming forest, sometimes coming so close to the tree tops that we almost seemed to brush them.

"My duty, of course, was to report the progress of the fire. Controlled at one point, it broke out at another, and it was through the messages from my 'plane to the ground set stationed just behind the fire line that the men were moved from one danger point to the next.

"Finally, the fire seeming nearly out along one side of the ridge, I sent the men to fighting it on the other side, where it had been left to rage uncontrolled. No sooner had the men scattered for the danger point than the brooding fire broke out again and it was necessary to recall half the men.

"It was a long fight and a hard one, but with the aid of the blessed old wireless, we finally won out. As a matter of fact, the wireless-equipped airplane has become as necessary to the Forest Service as ships are to the navy.

"In the old days," he went on, seeing that the boys were still deeply interested, "when they depended upon the ordinary telephone to convey warnings of fires they were surely leaning upon a broken reed.

"Often, just when they needed the means of communication most, the fire would sweep through the woods, destroying trees to which the telephone wires were fastened, and melting the wires themselves. So the eyes of the Forest Service were put out and they were forced to work in the dark."

"But I should think," protested Bob, "that there would be times when even wireless would be put out of the job. Suppose the fire were to reach one of the stations equipped with wireless. What then?"

Mr. Bentley laughed as though amused at something.

"I can tell you an interesting incident connected with that," he said. "And one that shows the pluck and common sense of radio operators in general—don't think that I'm throwing bouquets at myself, now, for first and last, I am a pilot, even if sometimes I find it necessary to employ radio.

"Well, anyway, this operator that I am speaking of, found himself in a perilous position. A fire had been raging for days, and now it was so close to his station that the station itself was threatened.

"One morning when he got up the smoke from the burning forest was swirling about the open space in front of the station and he knew that before long he would be seeing flame instead of smoke. The fire fighters had been working ceaselessly, fighting gallantly, but the elements were against them. The air was almost as dry and brittle as the wood which the flames lapped up and there was a steady wind that drove the fire on and on.

"If only there might come a fog or the wind change its direction! But the radio man had no intention of waiting on the elements. I don't believe he gave more than a passing thought to his own safety—his chief interest was for the safety of his beloved apparatus.

"He decided to dismantle the set, build a raft and set himself and the apparatus adrift upon the water in the attempt to save it.

"And so he worked feverishly, while the fire came closer and he could hear the men who were fighting the fire shouting to each other. Finally he succeeded in dismantling the set and got it down to the water's edge.

"Here he built a rough raft, piled the apparatus upon it, jumped after it, and drifted out into the middle of the lake."

"Did the station burn down?" asked Jimmy excitedly.

"No, fortunately. The wind died down in the nick of time, giving the men a chance to control the blaze. When it was evident the danger was past, the operator set up his apparatus again and prepared to continue his duties, as though nothing had happened.

"There you have the tremendous advantage of radio. There were no wires to be destroyed. Only a radio set which could be dismantled and taken to safety while the fire raged."

"That operator sure had his nerve with him, all right," said Bob admiringly.

"More nerve than common sense perhaps," chuckled Mr. Bentley. "But you certainly can't help admiring him. He was right there when it came to grit."

After a while they began to discuss technicalities, and the boys learned a great many things they had never known before. The pilot happening to mention that there were sometimes a number of airplanes equipped with radio operating within a restricted district, Joe wanted to know if they did not have a good deal of trouble with interference.

"No. There was at first some interference by amateurs, but these soon learned to refrain from using their instruments during patrol periods.

"You see," he explained, "we use a special type of transmitting outfit aboard our fire-detection craft. It's called the SCR-Seventy-three. The equipment obtains its power from a self-excited inductor type alternator. This is propelled by a fixed wooden-blade air fan. In the steam-line casing of the alternator the rotary spark gap, alternator, potential transformer, condenser and oscillation transformer are self-contained. Usually the alternator is mounted on the underside of the fuselage where the propeller spends its force in the form of an air stream. The telegraph sending keys, field and battery switch, dry battery, variometer and antenna reel are the only units included inside the fuselage.

"The type of transmitter is a simple rotary gap, indirectly excited spark and provided with nine taps on the inductance coil of the closed oscillating circuit. Five varying toothed discs for the rotary spark gap yield five different signal tones and nine different wave lengths are possible.

"So," he finished, looking around at their absorbed faces, "you see it is quite possible to press into service a number of airplanes without being bothered by interference."

"It sounds complete," said Bob. "I'd like a chance to see one of those sets at close range sometime."

The time passed so quickly that finally the visitor rose with an apology for staying so late. The radio boys were sorry to see him go. They could have sat for hours more, listening to him.

"That fellow sure has had some experiences!" said Joe, as, a little later, the boys mounted the stairs to Bob's room. "It was mighty lucky we happened along while he was here."

"You bet your life," said Herb. "I wouldn't have missed meeting him for a lot."

"Say, fellows," Jimmy announced from the head of the stairs, "I know now what I'm going to do when I'm through school. It's me for the tall timber. I'm going to pilot an airplane in the service of my country."

"Ain't he noble?" demanded Herb, grinning, as the boys crowded into Bob's room.



CHAPTER VIII

NEAR DISASTER

Several days later while the radio boys were experimenting with their big set and talking over their interesting meeting with the Forest Service ranger, Herb displayed an immense horseshoe magnet.

"Look what he's got for luck," chortled Jimmy. "The superstitious nut!"

"Superstitious nothing!" snorted Herb. "If I'd wanted it for luck I wouldn't have got a magnet, would I? Any old common horseshoe would have done for luck."

"Well, what's the big idea?" asked Bob, looking up from the audion tube he was experimenting with. "Or is there any?" he added, with a grin.

"You bet your life there is!" returned Herb. "It's got to do with that very audion tube you're fussing with."

"Ah, go on," jeered Joe, good-naturedly. "What's a magnet got to do with an audion tube, I'd like to know!"

"Poor old Herb," added Jimmy, with a commiserating shake of the head.

"Say, look here, all you fellows! Don't you go wasting any pity on me," cried Herb hotly. "If you don't look out, I won't show you my experiment at all."

"Go on, Herb," said Bob consolingly. "I'm listening."

"Well, I'm glad there's one sensible member of this bunch!" cried Herb, and from then on addressed himself solely to Bob. "Look here," he said. "You can make the audion tube ever so much more sensitive to vibration if you put this magnet near it."

"Who says so?" asked Bob, with interest.

"I do. Here, put on the headphones and listen. I'll prove it to you."

Bob obeyed and tuned in to the nearest broadcasting station where a concert was scheduled. As soon as he signified by a nod of his head that the connection was satisfactory Herb placed the big horseshoe magnet in such a position that the poles of the magnet were on each side of the tube.

Sure enough, Bob was amazed at the almost magical improvement in the sound. It was clearer, more distinct, altogether more satisfactory. He listened in for another moment then wonderingly took off the headphones while Herb grinned at him in triumph.

"Well, what do you think?" asked the latter while Joe and Jimmy looked at them curiously.

"Think?" repeated Bob, still wonderingly. "Why, there's only one thing to think, of course. That fool horseshoe of yours, Herb, is one wonderful improvement. I don't know how it works, but it surely is a marvel."

Herb glanced at Jimmy and Joe in triumph.

"What did I tell you?" he said. "Perhaps now you'll believe that my idea wasn't such a fool one after all."

"But what did it do, Bob?" asked Joe, mystified.

"It increased the sensitivity of that old audion tube, that's what it did," replied Bob, absently, his mind already busy with inventive thoughts. "I can't see yet just how it accomplished it, but the connection with the station was certainly clearer and more distinct than usual."

"But how can a magnet increase the sensitivity of a vacuum tube?" asked Jimmy, not yet wholly convinced. "It doesn't make sense."

"Well, I don't see why not," contradicted Joe slowly. "I suppose the improvement is due to the magnetic effect of the magnet upon the electrons flowing from the filament to the plate. I don't exactly see why it should be an improvement, but if it is, then there must be some reason for it."

"I wish we could find the reason!" cried Bob excitedly. "If we could make some improvement upon the vacuum tube——"

"Don't wake him up, he is dreaming!" cried Herb. "If you don't look out, old boy, you'll have us all millionaires."

"Well, there are worse things," retorted Bob, taking the magnet from Herb's hand and placing it near the tube. "This has given us something to think about, anyway."

For a while they puzzled over the mystery, trying to find some way in which the discovery might be made to serve a practical purpose—all except Herb, who retired to one corner of the "lab" to fuss with some chemicals which he fondly hoped might be used in the construction of a battery.