"Allen Chapman" was one of the pseudonyms used by the Stratemeyer Syndicate for its juvenile books. The actual writer of the first five Radio Boys books was John William Duffield, an experienced author who turned 63 years old in 1922. The book forewords were written by Jack Binns, who had gained fame as the radio operator aboard the S.S. Republic, when it sank in 1909.

James D. Keeline has put together an extensive review of this topic at
'Radio Boys' series by 'Allen Chapman' and Others.
 
The Radio Boys' First Wireless, Allen Chapman, 1922, pages v - vi:
FOREWORD

BY  JACK  BINNS

    IT is very appropriate at this moment when radio has taken the country by storm, and aroused an enthusiasm never before equaled, that the possibilities for boys in this art should be brought out in the interesting and readable manner shown in the first book of this series.
    Radio is still a young science, and some of the most remarkable advances in it have been contributed by amateurs--that is, by boy experimenters. It is never too late to start in the fascinating game, and the reward for the successful experimenter is rich both in honor and recompense.
    Just take the case of E. H. Armstrong, one of the most famous of all the amateurs in this country. He started in as a boy at home, in Yonkers, experimenting with home-made apparatus, and discovered the circuit that has revolutionized radio transmission and reception. His circuit has made it possible to broadcast music and speech, and it has brought him worldwide fame.
    He had no elaborate laboratory in which to experiment, but he persevered and won out. Like the Radio Boys in this story, he was confronted with all kinds of odds, but with true American spirit he stuck to his task and triumphed.
    The attitude of the government toward the wireless amateur is well illustrated by the expressions of Secretary of Commerce Herbert Hoover, and is summed up in his declaration, "I am for the American boy."
    No other country in the world offers such opportunities to boy experimenters in the radio field. The government realizes that there is always a possibility of other important discoveries being made by the boy experimenters, and that is the reason it encourages the amateur.
    Don't be discouraged because Edison came before you. There is still plenty of opportunity for you to become a new Edison, and no science offers the possibilities in this respect as does radio communication.
Binns signature

Pages 9-11
THE  RADIO  BOYS'  FIRST  WIRELESS 


CHAPTER  I


THE  AUTO  CRASH

    "How about it, Joe?" asked Bob Layton of his chum, Joe Atwood, as they came out of school one afternoon, swinging their books by straps over their shoulders. "Going up to Dr. Dale's house to-night?"
    "You bet I am," replied Joe enthusiastically. "I wouldn't miss it for a farm. I'm keen to know more about this wireless business, and I'm sure the doctor can tell us more about it than any one else."
    "He sure does get a fellow interested," agreed Bob. "He isn't a bit preachy about it, either. Just talks to you in words you can understand. But all the time you know he's got a lot back of it and could tell you ten times as much about it if you asked him. Makes you feel safe when you listen to him. Not a bit of guesswork or anything like that."
    "What are you fellows chinning about?" asked Jimmy Plummer, one of their schoolmates, who came up to them at that moment. "You seem all worked up about something."
    "It's about that talk Dr. Dale is going to give us to-night on the wireless telephone," answered Bob, as he edged over a little to give Jimmy room to walk beside them. "You're going, aren't you? The doctor said he wanted all the boys to come who could."
    Declared Jimmy, with a grin, "But eats or no eats, I'm going to hear what the doctor has to say. I got a letter the other day from a cousin of mine out in Michigan, and he told me all about a set that he'd made and put up himself. Said he was just crazy about it. Wanted me to go into it so that he and I might talk together. Of course, though, I guess he was just kidding me about that. Michigan's a long way off, and it takes more than a day to get there on a train."
    "Distance doesn't make much difference," declared Bob. "Already they've talked across the Atlantic Ocean."
    "Not amateurs?" objected Joe incredulously. "Yes, even amateurs," affirmed Bob. "My dad was reading in the papers the other night about a man in New Jersey who was talking to a friend near by and told him that he was going to play a phonograph record for him. A man over in Scotland, over three thousand miles away, heard every word he said and heard the music of the phonograph too. A ship two thousand miles out on the Atlantic heard the same record, and so did another ship in a harbor in Central America. Of course, the paper said, that was only a freak, and amateur sets couldn't do that once in a million times. But it did it that time, all right. I tell you, fellows, that wireless telephone is a wonder. Talk about the stories of the Arabian Nights! They aren't in it."
Pages 28-45:

CHAPTER  III

WONDERS  OF  WIRELESS

    "HOW are you, boys?" asked a pleasant voice, and the lads looked up to see Dr. Amory Dale, the pastor of the "Old First Church" of Clintonia, standing beside them.
    Most of them responded cordially, for they liked and respected him. There was no stiffness or professionalism about him to make them feel that they were being held at a distance. He was comparatively young, somewhere in the early thirties, and had the frame and bearing of an athlete. There were rumors that he had been a star pitcher on his college baseball nine and a quarterback on a football eleven whose exploits were still cherished in the memory of his institution. He was a lover of the out-of-doors and there was a breeziness and vitality that radiated from him and made him welcome wherever he went. He kept in touch with modern science, and it was said that he would have embraced a scientific career if he had not felt it his duty to enter the pulpit.
    The minister's house adjoined the big stone church, which was on West Main Street and divided the business from the residential part of the street. It was a roomy, capacious structure, and at about eight o'clock that night it became a place of pilgrimage for a large number of the boys of the town. Buck Looker and his cronies were conspicuous by their absence, but this was a relief rather than a privation.
    Bob and his friends were among the first corners. They were warmly greeted by Dr. Dale and ushered into the large living room of the parsonage. The portières had been drawn back between the front and back rooms so that nearly the whole ground floor was thrown into one big room. Extra chairs had been brought in so that there were accommodations for a large number. There were no grown people in the gathering, for the doctor had especially confined his invitation to the boys, who, he knew, would feel more at ease in the absence of their elders.
    From the time the boys entered the room their eyes were fixed on a box-like contrivance that was placed on a table close up against the wall of the further room. It had a number of polished knobs and dials and several groups of wires that seemed to lead in or out of the instrument. Connected with it was a horn such as was common enough in the early days of the phonograph. There were also several pairs of what looked like telephone ear pieces lying on the table.
    They eyed it with intense curiosity, not unmixed with awe. They had already heard and read enough of the wireless telephone to realize that it was one of the greatest marvels of modern times. It seemed almost like something magical, something which, like the lamp of Aladdin, could summon genii who would be obedient to the call.
    The rooms were comfortably filled when Dr. Dale, with a genial smile, rose and took up his stand near the table.
    "Now, boys," he said, "I've asked you to come here to-night so that we can talk together and get a little better idea of some of the wonders of the world we are living in. One of those wonders and perhaps the most wonderful of all is the wireless telephone," and here he laid his hand on the box beside him. "Most of you have heard of it and want to learn more about it. I'm going to try to explain it to you just as simply as I possibly can. And I'm not going to do all the talking either, for I want you to feel free to ask any questions you like. And before I do any talking worth mentioning, I'm going to give you a little idea of what the wireless telephone can do."
    The boys watched him breathlessly as he handled two of the knobs at the side of the box. A moment later they heard the clear, vibrant notes of a violin playing a beautiful selection from one of the operas. The music rose and swelled in wonderful sweetness until it filled the room with the delicious melody and held all the hearers entranced under its spell. It was evident that only the hand of a master could draw such exquisite music from the instrument.
    The doctor waited until the last notes had died away, and smiled with gratification as he saw the rapt look on the faces of his visitors.
    "Sounds as if it were in the next room, doesn't it?" he asked. "But that music came from Newark, New Jersey."
    "Gee," whispered Jimmy to Bob, alongside whom he was sitting, "that's nearly a hundred miles from here."
    "But there's no need of confining ourselves to any place as near as that," continued the doctor. "What do you say to listening in on Pittsburg? That's only a trifle of four hundred miles or so from here."
    "He calls four hundred miles a trifle!" breathed Jimmy. "Pinch me, somebody. I must be dreaming."
    Joe on his other side pinched him so sharply that Jimmy almost jumped from his chair.
    "Lay off there," he murmured indignantly. "S-sh," cautioned Bob, for by this time the doctor had made another adjustment.
    Then into the room burst the stirring strains of the "Stars and Stripes Forever" played by a band that had a national reputation. The rhythm and dash and fire of the performance were such that the boys had all they could do to keep their seats, and, as it was, their feet half unconsciously beat time to the music.
    "Hit you hard, did it?" smiled Dr. Dale, who, to tell the truth, had been keeping time himself. "Well, I don't wonder. I'd hate to see the time when music like that wouldn't shake you up. But now we'll go a few hundred miles farther and see what Detroit has to give us."
    Jimmy was past speech by this time and could only look at his comrades in helpless wonder.
    Then the twang of a banjo sounded through the rooms and to the thrumming of the strings came a voice in rich negro dialect:

"It rained all night the day I left,
The next day it was dry,
The sun so hot I froze to death
Susanna, don't you cry."

CHAPTER  IV

MYSTERIOUS  FORCES

    THE boys broke out in roars of laughter in which the doctor joined heartily.
    "You see how it is," he said, as the song came to an end. "There's hardly anything you can think of that you can't hear over the wireless telephone. It takes you anywhere you want to go in a fraction of a second. In the last few minutes, we've covered quite a section of the United States, and with a still stronger instrument we could go right out to the Pacific coast and hear the barking of the sea lions at the Golden Gate."
    "Wonder if we could hear the barking of the hot dogs at Coney Island," whispered the irrepressible Herb, who would have his joke.
    Bob nudged him sharply and Herb subsided.
    "And you can pick out any kind of entertainment you want," the doctor went on. "The great stations from which this music was sent out have programs which are published every day, together with the exact time that the selections will be given. At a given minute you can make your adjustment and listen to a violin solo, a band concert, a political speech, a sermon, or anything else that you want. If it doesn't please you, you can shut it off at once, which is much easier and pleasanter than getting up and going out from an audience.
    "We'll have some more selections later on in the evening," he continued, "but now I want to explain to you how this thing is done. I can't hope to do much more than touch the surface of the subject to-night, for I don't want to tire you out, and there'll be plenty of other nights and days when I hope you boys will call upon me for any information that you want and I can give.
    "Of course the whole thing is based on electricity, the most wonderful thing that perhaps there is in the whole physical world. Nobody knows what electricity is--Mr. Edison himself doesn't know. We only know that it is a wonderful fluid and that the ether is full of it. But though we don't know what it is, scientific men have learned how to develop and use its energy, and among other things they have harnessed it in the service of the wireless telephone.
    "Take for instance a quiet lake. It may seem absolutely still, but if you throw a stone in it you start a number of ripples that keep spreading further and further out until they break on the shore. So if you hit a drum with a stick, sound waves are stirred up that keep spreading out very much like the ripples on the lake.
    "Now electricity is something like that. It doesn't begin to act until you do something to it. The impulse to ripple is in the quiet lake all the time, but it doesn't ripple until you throw the stone in it. The sound quality is in the drum, but you don't hear it until you hit the drum with a stick. So you've got to put into the ether something that disturbs the electricity in it, something that stirs it up, and then this disturbance makes waves that travel on, just as the waves on the lake follow one another and just as the sound waves from the drum keep pushing each other along.
    "A man named Hertz discovered a way of stirring up this energy, snapping it, you might say, as a man snaps a whip. It was found that these waves could be made long enough and strong enough to go all the way across the Atlantic Ocean, in fact to go around the world."
    "Around the world!" murmured Jimmy, and again he was tempted to ask somebody to pinch him, but remembered his previous experience and stopped just in time.
    "Now," continued the doctor, "you may ask what this has to do with the voice, for it is with the voice that one talks over the 'phone. The whole principle of the wireless telephone is based on the fact that sound can be transformed into electricity and then can be transformed back into sound again. I know," he said, with a smile, "that that sounds very much like saying that you can make eggs into an omelet and then get the omelet back into separate eggs again"--here there was an audible snicker from the boys--"but that is very much like what is done by the wireless, although it doesn't exactly fit the case.
    "Now see what a wonderful increase in power you get the moment the sound waves are changed into electric waves. Sound goes at the rate of one thousand and ninety feet a second. Electrical energy travels at the rate of one hundred and eight-six thousand miles a second. In other words it could go around the world more than seven times in a single second.
    "When you speak into a telephone, unless you are greatly excited, you don't use more than a fiftieth part of the power of your voice. But by the time that sound has been caught up and churned, as it were, into electrical energy it is more than a hundred thousand times as loud and strong.
    "Suppose now, just as an illustration, that you were going to telephone to Europe. You'd pick up the 'phone and give your message. That sound would go in the form of a tiny electrical impulse into one of the great sending stations on the Atlantic Coast, we'll say, and there it would be caught up by a powerful lot of electrical machines, amplifiers, alternators, and others, that would keep making it stronger and stronger until finally it was flung out into space from the ends of the great wires or antennae. Out and out it would go until it struck a lot of wires on the other side of the ocean. Then it would go through another process that would gradually change the electrical impulse back into sound again, and the man at the other end of the telephone would hear your voice, just as one does now when you 'phone to any one in this town."
    He paused for a moment, and there was a long drawn breath on the part of his auditors that testified to the rapt attention with which they had followed him into this fairyland of science.
    "So much for the theory and principle of the wireless," resumed the doctor. "Of course I've only scratched the surface, and if I talked to you all night there'd be still lots left to say. But we only need to know a little about it to put it to practical use. And it is the practical use of the wireless telephone that I'm especially interested in for the sake of you boys. I'm satisfied that there's hardly anything that could give you more pleasure or more benefit than for each of you to have one of these contrivances in your own home. It's a wonderful educator, it helps to develop your interest in science, and what will perhaps appeal to you most of all, you can have more fun with it than anything else I know of."
    Here Bob put in a question that was in the minds of many of the others.
    "Does it cost very much, Doctor?" he asked.
    "Not very much," the doctor replied. "Of course, some of the more powerful ones with vacuum tubes and other high class improvements run into the hundreds of dollars. But some very good receiving sets--and that's all you could use at the start, for it takes considerable time and you have to get a license before you are permitted to transmit--can be bought for from twenty-five to seventy-five dollars."
    There was a little gasp at this, some of which was due to a feeling of disappointment. It seemed beyond the range of what they could save up from their pocket money, and while the parents of some of them were well to do, others came from simple and frugal homes where every dollar had to be carefully counted.
    The doctor was quick to note the expression on many faces, and took pains at once to remove any feeling of discouragement.
    "But don't let that bother you at all," he said, "for with a little thought and planning any one of you will be able to build a telephone receiving set for himself at hardly any cost at all. In fact, I'd much rather have you build one than buy one, for in that way you'll get an understanding of the whole thing that otherwise you might not get at all. You'd be surprised perhaps if I told you that this set here was built by me and I wouldn't exchange the experience I've had in putting it together for a good deal of money."
    "But you knew how to do it," put in Joe, "while we don't know the first thing about it. We wouldn't know how to start, even, let alone finish one."
    "I was coming to that," returned Dr. Dale, smiling. "As some of you know, I've fitted up a workshop in the barn behind this house where I do a good deal of tinkering in my spare hours. Now I'm going to ask you boys to come out there next Saturday and see me build a wireless receiving set from A to Z. You'll be surprised to see how much can be done with a few things that cost very little money and with a lot of things that don't cost any money at all. How about it, boys?"
    It was almost with a whoop that the invitation was accepted by his eager hearers, and the minister smiled with gratification at their enthusiasm.
    "Now that's all the talking I'm going to do tonight," he said. "And as talking's rather dry work, I'm going to have a little refreshment. Will you boys join me?"
    Would they join him? They would and they did, and the havoc they wrought on the sandwiches and cake and ice-cream that were brought in and passed around was something to be remembered. Jimmy in particular ate until his eyes bulged and fully sustained his previous reputation. And while they ate, the doctor turned on one lively selection after another, finishing with a selection from a jazz band that sent them into a frenzy of laughter.
    They were still tingling with it as they finally said good-night to the doctor and started on their way home.
    "Oh, you wireless telephone!" exclaimed Herb.
    "Isn't it a wonder?" ejaculated Joe.
    "Wonder!" repeated Bob. "It's a miracle!"

CHAPTER  V

CROOKED  WORK

    "WE'VE got to get busy right away and rig up wireless telephones of our own," continued Bob. "Of course they won't be anything like the doctor's, but they ought to be good enough for us to get a lot of fun out of them."
    "You bet we will," agreed Joe. "Gee, I can't wait to get at it! If it wasn't so late I believe I'd start in figuring on it to-night."
    "Count me in on it too," chimed in Jimmy. "In a week or so we'll be sending messages everywhere. I'll be talking maybe to that cousin of mine in Michigan."
    "Come out of your trance, Jimmy," laughed Bob, clapping him on the shoulder. "Things don't move so fast as that. It'll be a good long time before you'll be sending any messages. You'll have to learn all about receiving them first; and believe me there's a good deal to learn about that. Then before you can send any messages you have to pass an examination and get a license. But for quite a time we'll have our hands full and our ears full with attending to the receiving end of the game. One step at a time is the rule in radio, as well as in anything else that's worth while."
    "I didn't know that," replied Jimmy, somewhat dashed by the information. "I had an idea that we could send just as soon as we got our sets made."
    "How about you, Herb?" asked Bob. "You're in it with the rest of us too, aren't you?"
    "With both feet," replied Herb. "I think that the wireless is the greatest thing that ever happened. But I don't know about making one for myself. I'm all thumbs when it comes to doing any mechanical work. You fellows are handy with tools, but I have all I can do to keep out of my own way. I guess I'll ask my dad to buy me a set and let it go at that."
    "That's what you think now," replied Joe, "but I'll bet when you see the rest of us getting busy, you'll pitch in too and make your own machine. Besides, from what the doctor says, it doesn't take a genius to put the thing together."
Pages 58-66:

    The days passed by swiftly until Saturday came and with it the opportunity the boys had looked forward to of going to Dr. Dale's workshop and getting a few practical points on the making of a wireless telephone set.
    They found the doctor at a bench that he had rigged up in his barn. On the wall was arranged a large variety of tools and on the bench were strewn several coils of wire and a number of objects the name and use of which the boys did not know.
    The doctor, who was in his shirt sleeves, extended a hearty welcome to the boys, who ranged themselves about him, and whose numbers were constantly augmented by newcomers until the barn was well filled.
    "What I want to do to-day, boys," he said, "is to show you how easy and simple it is to put up a wireless telephone receiving set without paying to spend very much money.
    "Now the first thing you have to get and put up is the aerial," he remarked, as he unwound a large coil of copper wire. "You want about a hundred or a hundred and twenty feet of that. You can extend it horizontally for about fifty feet, say, for instance, from the side or back of your house to the barn or the garage, and then have it go up as high as it can go. The upper end doesn't have to be in the outer air, for the sound will come along it if it's in the attic. Still it's better to have it outside if possible. The lower end of the wire has to be connected with the ground in some way, and you can fix that by attaching it to a water pipe or any other pipe that runs into the ground. A good way is to let it down the side of the house and put it through the cellar window and fasten it to a pipe.
    "After you have your aerial you want to get the rest of the apparatus together. The first thing to do is to get a baseboard which will serve as the bottom of the receiving box. Something like this," and he put his hand on a board about eighteen inches long, twelve inches wide, and about an inch thick. "This is the platform, as it were, on which the different parts of the apparatus are to rest.
    "Now since your ear alone can't detect the waves that are coming to and along your aerial, you have to have a sort of electrical ear that will do this for you. Here it is," and he picked up a piece of crystal and a wire of phosphor bronze. "When this wire comes in contact with this bit of crystal the mysterious waves become audible vibrations.
    "But this isn't enough. You've got to get in tune with the sending station in order to understand the sounds you hear. When your vibration frequency is the same as that from which the message is sent, you can hear as clearly as though the voice or instrument were in the next room. Now here's a piece of a curtain pole that's about a foot and a half long. You see that I've wound around its entire length, except for about a half inch at either end, a coil of wire. This is called the inductance coil. You will notice that the wire is covered with cotton except for this little strip of wire extending lengthwise where I've scraped the cotton off with sandpaper so as to accommodate the sliding contacts. These sliding contacts can be made from curtain rings with holes punched in them, through which are passed copper rivets. These rivets press against the bare path of the coil and can be moved to and fro until you find the exact point where your set is in tune with the sending station."

CHAPTER  VII

IN  THE  DARK

    "Now," continued Dr. Dale, as he glanced round the circle of eager faces, alight with interest in the subject, "we're getting pretty close to the time when one picks up the receiver and begins to listen in.
    "But as the electric vibrations, if left alone, would have a good deal of trouble in passing through the telephone receiver, we must have a condenser to help them out. This is very easily made by gluing a piece of tinfoil about one and a half inches square to each side of a sheet of mica. Then you must have two strips of tinfoil, one extending from each side of the mica. If you haven't any mica, a sheet of ordinary writing paper will do, though the mica is better.
    "The telephone receiver you will have to buy, as a satisfactory one can't very well be made by an amateur. The receiver ought to have a high resistance to get the best results.
    "There," he said, as he laid the telephone receiver on the bench, "those are the essential things you have to have in order to make a set of your own. With these things only, it will of course be a simple set and have a limited range. There are a hundred improvements of one kind or another that you'll learn about as you get more expert, and these can be added from time to time. But the special thing I wanted to prove to you to-day was that it would take only a very small expenditure of money to get this material together. You see how many things I've used that any one of you can find about the house, such as tinfoil, curtain poles, curtain rings, wood for the box, and so on. The wire needed for your tuning coil and your aerial can be obtained for less than a dollar. The detector, including the crystal, can be got for another dollar. An excellent receiver can be bought for two dollars. A few minor things will be needed at perhaps five or ten cents each. Altogether the cost of the set can be brought within five dollars."
    This was good news to the boys, many of whom began at once a mental calculation as to the amount of their pocket money, while others began to figure on odd jobs that might bring them in the required amount, in the event that their parents would not supply the money.
    With a few deft movements the doctor attached the various parts of the apparatus to their proper places on the baseboard. There was not time that day to put up the aerial, but he gave them practical illustrations of how to use the detector by pressing the point of the wire firmly against the crystal, how to slide the rings back and forth until they found the point of greatest loudness and clearness, and all other points essential to using the set successfully. Not all the boys caught on to all that was involved, but to the majority it was made reasonably clear. To Bob and Joe, who had followed every point of the demonstration with the keenest attention, the operation of the receiving set was made as clear as crystal, and they had no doubt of their ability to construct a set for themselves. Herb's attention had wandered somewhat, because in the back of his mind there still lurked the idea of buying a set ready made. Jimmy had been somewhat distracted by looking about in various parts of the barn to see if he could detect the presence of any "eats," and his ideas were somewhat hazy in consequence.
    "Well, boys," at last said the doctor, with a smile, "I guess we'll call it a day. But remember that if at any time you are puzzled and want more information all you have to do is to come and ask me. I'll gladly lay aside my work any time to help you youngsters out."
    The boys thoroughly appreciated the doctor's cordiality and the demonstration that he had given them, and most of them took occasion to tell him so as they said good-bye to him and filed out of the extemporized workshop.
    "He certainly does make things clear," said Bob enthusiastically, as he and his friends made their way toward their homes.
    "Not only that, but he makes you want to do them," said Joe. "After seeing and hearing him this afternoon, I'd ten times rather make a set than buy one."
    Jimmy agreed with them, and even Herb seemed ready to reconsider the idea of getting one ready made, though he was not yet quite prepared to surrender.
    "All of you come over to my house to-night," said Bob, as they neared their homes. "We haven't got the materials yet, but we can go over again what the doctor told us to-day and make sure that we've got it all straight in our minds. What one forgets, the other may remember. Then when we do get the stuff we can put a little snap and speed into making the set."
    "That will be bully," replied Joe, and the others agreed with him. "For my part," Joe continued, "I count every day lost that we have to go without it. I sure am becoming a radio fan."
    It turned out that Herb was prevented from coming by unexpected company but the others were there. Their talk that night was animated and enthusiastic, so much so in fact that the time passed more quickly than they imagined, and they were surprised when the clock struck eleven.
Pages 70-84:

CHAPTER  VIII

GETTING  A  START

    THE idea of having their own radio outfit and being able to hear all the wonderful things going on in the air about them so fascinated the boys that they could talk or think of little else. Even Jimmy Plummer became so excited that his mother declared he was actually forgetting to eat, a statement that his father flatly refused to believe at first.
    "You see how it is, Dad," said Jimmy, mournfully. "If you don't give me the money to get some wireless stuff I'll just pine away and die."
    Said his father, with a twinkle in his eye, "I suppose if you've set your heart on it I might as well come across now as later and save myself from being pestered to death. How much do you suppose you'll need to get started?"
    "The other fellows are figuring that about five dollars apiece will buy most of the things we'll need--at first, anyway," he added, with a careful eye to the future.
    "All right, here it is," said Mr. Plummer. "And I suppose the next thing we know you'll be breaking your neck falling off the roof while you're trying to put up aerials, or whatever it is they call the contraptions."
    "Leave that to me," said Jimmy. "And I'll bet you'll get lots of fun out of this too, Dad, when we get it going."
    "Well, maybe so," said his father. "But I don't take much stock in the whole business. Some wonderful things happen these days, though, and you may be able to change my mind."
    "I'm sure I will," said Jimmy, with conviction. "And if you had heard what I did at Doctor Dale's house, I'll bet you'd want a radio outfit as much as I do."
    "Well, go ahead and see what you can do, Son. If you can really get the thing working, so much the better."
    The next day Jimmy lost no time in hunting up his friends and telling them of his good fortune. He found that the others had not been far behind him in procuring the necessary cash. That afternoon they all descended on the hardware store, whose proprietor had laid in a stock of the materials that would be likely to be needed in the construction of simple radio outfits. The hardware merchant was glad to see them, but somewhat surprised also.
    "Gosh!" he exclaimed, when he learned what the boys had come for. "When that salesman from New York talked me into stocking up with all that stuff, I never thought I'd get a sale for it in the next ten years. And now here's all you youngsters coming in here after it with money in your fists."
    "Yes, and you'd better lay in a whole lot more of it, Dave," said Bob Layton. "It won't be long before everybody in this town will be wanting a wireless radio outfit."
    "Well, I guess I've got enough in the store now to start you fellows on your way," said Dave Slocum, the proprietor. "Now, what all do you need?"
    There followed a time of much consultation and anxious questioning before all the enthusiastic young experimenters were satisfied that they were getting the most useful things their limited amount of capital would buy. Dave Slocum sold more feet of copper wire in that one afternoon than he had in the previous five years, not to mention insulators, resistance wire, detectors, head sets, and all the other paraphernalia necessary to the beginner. At last all the various purchases were tied into neat bundles, and the excited boys swarmed out into the street.
    "Let's go to my house and get started right away," proposed Bob. "It will be quite a job to get the aerial strung, and the sooner we do it the better it will suit me."
    The others were of the same mind, and they made the distance to the Layton home "on the jump" with Jimmy puffing valiantly in the rear in a desperate endeavor to keep up with his more active comrades.
    "Never mind about pies now," said Herb. "The question before the house is to get an aerial strung from Bob's house to the barn. What's the best way to get up on the roof, Bob?"
    "There's a trap door in the roof not far from the chimney," replied Bob. "I was thinking that we could make a mast and lash it to the chimney. That would give us one secure anchorage for the aerial, and the other we can fasten to the roof of the barn easily enough."
    "What are we going to make the mast out of?" inquired Joe.
    "There's a nice piece of four by four lumber out in the barn," replied Bob. "I was thinking that we could leave it square at the bottom and plane it off round at the top, so as to look better. I don't see why that won't fill the bill all right."
    "Sounds all right," said Herb, and, with Bob leading, all four boys piled out to the big barn back of the house. Bob produced his scantling and hunted up a big plane. Then the boys set to with a will, and in a short time had the rough timber nicely smoothed off, with a slight taper toward the top. Then they screwed in a large hook, bought for the purpose, and after providing themselves with a generous length of rope, repaired to the roof of the house.
    As Bob had told them, there was a large scuttle leading from the attic onto the roof, and one after another they clambered out through this. The roof sloped gently at this point, and while they found it necessary to be careful, they had little difficulty in reaching the chimney. Before erecting the mast they fastened one end of the aerial over the hook in it. The aerial consisted of a single, number fourteen, hard drawn copper wire, insulated at each end by an earthenware insulator having two hooks embedded in it. One of these hooks went over the hook in the mast, while the other had the end of the wire attached to it. A similar insulator was provided at the other end of the wire, thus preventing its becoming grounded to the house or barn.
    Having hooked up one end of their aerial, the boys erected the mast against the chimney, and lashed it firmly in position with the rope they had brought up.
    "There!" exclaimed Bob, when everything was fixed to his liking, "that mast looks as though it might stay put a while. Now let's rig up one on the barn, and we'll have the first part of our job done, anyway."
    Clambering back to the scuttle, the boys dropped through to the attic floor and hurried downstairs. It was beginning to get dark, and as they wanted to get the aerial up while daylight lasted, everything went with a rush.
    Of course there was no convenient chimney on the barn to act as a support for the mast, but they finally rigged up a mast at one end of the barn, nailing it securely to the siding boards. Then they drew the copper wire through the hook in the insulator until there was just a little slack, cut off the wire, and wound it securely. Then they all gazed with pride at their handiwork, and had the comfortable feeling that comes of work well done.
    "Hooray!" shouted Jimmy. "That's what I call a good job, and it didn't take us such a long time, either."
    "Yes, but that's only the beginning," said Joe. "I only wish we had more time to-night. I feel as though I'd like to keep right on now and not stop until we're actually receiving."
    "When you two follows are all through arguing, maybe we can go up and hook on our leading-in wire to the aerial," said Joe, impatiently. "We ought to get that much done before dark, anyway."
    "I don't know about that, Joe," objected Bob. "It's almost dark now, and we could do it better and easier in the daylight. What do you say if you all come around after supper and we'll dope out a wiring diagram and maybe make a start on building the tuning coil."
    Joe reluctantly consented to this, and the four companions separated for the time being, after promising to return to Bob's house that evening. And true to their promise, the boys had all returned to the Layton home by eight o'clock that evening, full of enthusiasm for the task that lay before them. Mr. Layton was mildly interested in the radiophone project, but after a few questions he retired to the library with the evening paper, leaving the boys to their own devices.

CHAPTER  IX

WORK  AND  FUN

    "WELL, fellows," said Bob, "here we are, all set for a busy evening. What shall we do first?"
    "Shall we get the tuning coil started?" suggested Bob. "It will take us quite some time to do that, but we might get the core wound tonight, anyway."
    As there was no objection to this, they all went down to the cellar, where Bob had rigged up a work bench and had a pretty complete stock of tools. Jimmy's father had made them a wooden form on which to wind the wire. This core was nothing but a plain cylinder of wood, about three inches in diameter and ten inches long. For Christmas, the year before, Mr. Layton had given Bob a small but accurately made bench lathe, operated by a foot pedal, and Bob mounted the roller between the lathe centers, holding one end in the chuck jaws. Then he produced a narrow roll of stout wrapping paper, such as is used for winding around automobile tires, and a bottle of shellac, together with a small, fine-haired brush.
    "First thing," he said, "we want to wind a few layers of shellacked paper on this core. Suppose I turn the core, you let the paper unwind onto it, Joe, and you can shellac the paper as it unrolls, Herb."
    "That leaves me with nothing to do but boss the job," said Jimmy, "and I don't see why I can't do that as well lying down as standing up, so here goes," and he stretched out luxuriously on an old sofa. "This must have been put here just for me, I guess," he continued, with a sigh of perfect contentment. "Get busy, you laborers, and flash a little speed."
    "We haven't got time to come and throw you off that sofa just now," said Bob. "But as soon as we get through with this job you'll vacate pretty quick. Are you fellows ready to start now?"
    "I've been ready for the last half hour," said Joe. "Start that jigger of yours going, and let's see what happens."
    Bob put a dab of shellac on one end of the paper to get it started, stuck the end on the wooden core, and then started winding the paper onto it at a slow speed. Joe moved the roll of paper back and forth to wind it smoothly and evenly, while Herb shellacked for all he was worth, giving himself almost as liberal a dose of the sticky gum as he gave the paper. It was not long before the core was neatly wrapped, and Bob stopped his lathe.
    "That looks fine," he said, eyeing the job critically. "Now, while that shellac is drying out a bit, let's see if we can't coax Doughnuts to get up off that couch."
    "You're welcome," retorted Joe. Then to Bob: "Do you think we can wind the wire on now, Bob?"
    "Why, I guess so," said Bob, testing the shellac with his finger. "It's getting pretty tacky now; so if we wind the wire on right away the shellac will help to hold it in place when it dries."
    "Well, start up the old coffee mill, then," said Herb. "If we can get the wire on as slick as we did the paper, it won't be half bad."
    But the wire was a more difficult thing to work, as they soon found. It required the greatest care to get the wire to lie smooth and close without any space between coils. More than once they had to unwind several coils and rewind them before they finally got the whole core wound in a satisfactory manner. But at last it was finished, all coils wound smooth and close, and the boys gazed at it with pardonable pride.
    "That doesn't look as bad as it might, does it?" said Bob.
    "I should say not!" exclaimed Joe. "The last time I was in New York I saw a coil like that in an electrical store window. I didn't know then what it was for, but as far as I can remember, it didn't look much better than this one."
Pages 91-110:

CHAPTER  XI

CLEVER  THINKING

    THE radio boys were at Bob's house on the dot, all but Jimmy, who to his great disgust had to do some work for his father, and so could not come.
    "I suppose we'll have to try to get along someway without his valuable assistance," said Herb. "When he told me he couldn't get here this afternoon he certainly felt sore about it."
    "I guess I know how he feels, all right," said Joe. "It would pretty near break his heart not to be able to work on this radio stuff now. I'm crazy for the time to come when we can pick our first message or music out of the air."
    "I guess you're no more anxious for that to happen than we are," said Bob. "Let's go downstairs and see what we can do."
    They all made their way to Bob's workroom in the basement, where they found the core well dried and the wire as firmly set on it as the most particular workman could desire.
    "Good enough!" exclaimed Bob, examining the core with loving pride. "We'll get this set up in a jiffy, and then we can make the condenser."
    Working together, the boys soon had two square blocks sawn out as end pieces, and they centered the core on these and screwed it fast. Then they drilled holes in the two upper corners of the square end pieces to fit two brass rods they had bought at the hardware store. These rods carried each a small sliding spring, or contact, which rubbed along the length of the tuning coil, one on each side. After they had bolted the brass rods securely in place, the coil was ready for use, except that the boys had first to scrape off the insulating enamel in the path of the sliding contacts, so that they could reach the copper coils. A sharp pen knife soon effected this, and the boys found themselves possessed of a neat, substantial tuning coil, at a cost of only a fraction of what it would have been if they had had to buy a coil already made. And in addition they had the satisfaction that comes of a good job well done, which more than compensated them for the labor involved.
    "That begins to look like business," exulted Joe. "We'll be putting Mr. Edison out of business pretty soon."
    "Yes, it's lucky he can't see that tuning coil," laughed Bob, "he'd be looking up the want ads in the papers, sure."
    "Oh, that coil won't be a patch on the condenser we're going to make," declared Herb.
    "I know we've got to have a condenser, but I'm blessed if I really understand what it is for," said Joe. "I know the doctor told us about it, but I guess I didn't get a very clear idea of what it was all about."
    "I'm not very clear on it either," admitted Bob. "But from what he said and what I've read, it seems to be a sort of equalizer for the electric current, storing it up when it's strong and giving it out when it's weak. It prevents the current getting too strong at times and burning something out."
    "That's the way I understood it, too," said Herb. "And Dr. Dale said that in the larger sets they have what they call a variable condenser, so that they can get more or less damping action according to the strength of the incoming current waves."
    "I guess I get the idea," said Joe. "But it's a pretty complicated thing when you first tackle it, isn't it?"
    "Yes, but it's just like almost anything else, probably--it's easy when you know how," said Bob.
    "It tells here how to make the condenser," said Herb, who had been looking over an instruction book that the boys had bought. "But it says the best thing to use for the plates is tinfoil. Now, where are we going to get the tinfoil from, I'd like to know!"
    "If you want to know real badly, I'll tell you," said Bob. "Right out of that box over in the corner. Just wait a minute and I'll show you."
    Bob stepped swiftly over to the box in question and produced a big ball of tinfoil, composed of separate sheets tightly packed together.
    "When I was a kid I used to collect this stuff and sell it to the junkman," he said. "This ball never got big enough for that, and I forgot all about it until a few days ago when I happened to come across it and thought that it would be just the thing for us to use now. We can easily peel off all the sheets we need, I guess. Some of them are damaged, but there are enough whole ones to do our trick."
    "Gee, that's fine!" said Joe. "Pry off some, Bob, and let's see if it will serve."
    With his knife Bob pried away at likely looking places, and soon had several large sheets off. These, when smoothed out, looked good enough for any purpose.
    "How many does the book say we'll need, Herb?" asked Bob.
    "It says eight or ten, each one about four inches square," answered Herb. "And it says they have to be separated by paraffined paper. How are we going to get hold of some of that?"
    "Paraffine wax is what they use to seal fruit jars," said Joe. "We ought to be able to get some of that easy enough."
    "Mother had a big cake of it last summer!" cried Bob. "Maybe she has some of it left. Wait here and I'll ask her," and he dashed up the stairs three steps at a time.
    In a few minutes he returned, having obtained not only the wax but a small sauce pan in which to melt it.
    "I thought I'd bring this along, so as to have it," he said; "but it's so near supper time that I don't think we'll have a chance to do much more--right now, anyway. What do you say if we knock off now and do some more work this evening after supper?"
    "Gee, I never thought it was that late," said Herb. "If Jimmy had been here, I suppose he would have been talking about supper for the last hour or so, and we'd have known what time it was."
    "Well, I'll be here for one," said Joe, "and I'll stop at Jimmy's house on the way home and tell him to get around, too."
    Bob went upstairs with them, and Herb and Joe went away together, after promising to come back as soon after supper as possible. After they had gone, Bob could not resist the temptation to go down and gaze with an approving eye on the shiny new tuner they had made, and dream of the many wonderful sounds that would soon come drifting in through that gleaming bit of mechanism.

CHAPTER  XII

FORGING  AHEAD

    THE Laytons had hardly finished supper that evening before Jimmy's cheery whistle was heard outside, and Bob jumped up to let him in.
    "Come in, old timer," Bob called to him. "Where's the rest of the bunch?"
    "Oh, I guess they'll be along pretty soon," said Jimmy. "I guess I'm a bit early, but I was so anxious to get around that I couldn't wait to come at a respectable time. I suppose I should be boning down for to-morrow's lessons, but I'd never be able to get my mind on them until get our outfit going."
    "I feel the same way," said Bob. "But at the rate we're going now it won't be very long."
    "Joe told me you finished the tuning coil this afternoon," said Jimmy. "I don't understand how you ever did it without my being here to tell you how, though."
    "Oh, we managed to patch it up some way," laughed Bob. "Come on down and look at it, and see if it's good enough to suit you."
    "Lead me to it," said Jimmy, and the two boys went downstairs.
    "Say, that's a pippin," said Jimmy, as Bob switched on the light and he caught sight of the finished tuner. "I couldn't have done it better myself. You've certainly made a first class job of it."
    "We thought it wasn't so bad," admitted Bob modestly. "Especially when one stops to think that you weren't here to give us the benefit of your advice."
    "That's the most surprising thing about it," said Jimmy. "But now that I'm here to-night, why, we can go right ahead and get a lot done. Seems to me it must be about time for Joe and Herb to show up."
    As though in answer to this thought, they heard a tuneful duet, and a moment later came a vigorous ring on the doorbell.
    "You go up and let them in, will you, Doughnuts?" said Bob. "I want to melt this paraffine and get things started right away."
    "Sure I will!" And Jimmy hastened off, returning a few minutes later with the missing members of the quartette.
    "It's about time you got here," said Jimmy. "Bob and I were wondering if we'd have to do all the work by our lonesome, as usual."
    "Gee, you don't know what work means," returned Joe scornfully. "Last evening you pretty near wore a hole in that old couch resting on it, and this afternoon you were enjoying yourself helping your father instead of coming here and doing a little honest work for a change."
    "Oh, yes, I enjoyed myself a lot!" exclaimed Jimmy. "I sawed enough one inch planks this afternoon to make either one of you loafers cry for help! And then you talk about my having enjoyed myself!"
    Said Joe, "When are you going to have that wax cooked good and tender, Bob?"
    "Suppose you leave the wax to me, and you get busy cutting out some squares of tinfoil and paper," suggested Bob. "This wax will be done a long time before you're ready for it."
    "All right, I'll do it," said Joe. "I don't suppose there's anybody in the world can beat me at cutting out squares of paper. There may be some things I can't do, but I sure shine at that."
    "Yes, I guess you can do that all right," admitted Bob. "But I can't be real sure until you give us a demonstration."
    "Here goes, then," replied Joe. "How big do they want to be?"
    "Four inches square, the book says, and I suppose the man that wrote it knew what he was talking about," said Bob. "That will do to start on, anyway."
    Joe carefully measured a square of paper to the required dimensions, and then used it as a pattern in cutting out the others. He soon had a number of neat squares ready, which he handed to Bob, who immersed them in the melted wax. While the paper was soaking this up, Joe cut out a corresponding number of tinfoil squares, leaving a projecting tongue on each one to serve as a terminal.
    "You're an expert at carpenter work, Doughnuts," said Bob. "If you feel as ambitious as usual you can cut a couple of squares out of that oak plank over in the corner. We'll need them for end pieces to this condenser."
    "Oh, that will be lots of fun," said Jimmy, who had been casting longing glances toward the old sofa. "I'd a good deal rather saw some more wood than take it easy. How big shall I make them?"
    "About five inches each way, I should say," answered Bob, reflectively. "That will give us room to drill holes in each corner to put the clamping bolts through. In that drawer under the table you'll find some drills. I think a three-sixteenth drill ought to be all right. There are four brass bolts in that bag on the table, and you can measure them and see what size drill you'll need. I bought them for three-sixteenth anyway."
    "You go ahead and cut out the pieces Jimmy," said Herb "I'll do the real hard work, like measuring the bolts and picking out the drill. Then when you get the end pieces cut out, the drill will be all ready for you to put the holes through."
    Jimmy gave him a withering glance, but rolled up his sleeves and set to work. Once started he made the sawdust fly, and before very long had two stout looking pieces of solid oak cut out.
    "Where's your drill, Herb?" he inquired then. "Don't tell me you haven't got that ready yet!"
    "All ready and waiting," was the reply, and Herb handed over the required tool. "Go to it, and see that you make a first class job of it."
    Clamping both pieces of wood in the vise, Jimmy ran the sharp hand drill through in a workmanlike manner, and then viewed his work with pardonable pride.
    "There you are," he said. "If this condenser doesn't condense, it won't be because it hasn't got two good end pieces, anyway."
    "It's funny that you should have to condense electricity," said Herb, with a twinkle in his eye. "It's just the same as milk, isn't it?"
    "Yes, it isn't," said Bob. "Another wise remark like that, and you'll find yourself out in the wide, wide world, young fellow."
    "I should say so," said Joe. "That was a fierce one, Herb."
    "Well, I'll promise to be good," returned Herb. "But I still think that was a pretty fine joke, only you fellows haven't got enough sense of humor to appreciate it."
    "Well, I guess this paper has soaked up all the wax it's going to, so we can go ahead with the rest of it," said Bob, as he started fishing squares of impregnated paper out of the saucepan.
    He laid one sheet on one of the blocks that Jimmy had cut out, and on top of that laid a sheet of tinfoil, then another sheet of paper and one of tinfoil, alternating in this way until he had a number of sheets lined up. The little tabs or projections on each sheet of tinfoil he arranged in opposite directions, so that half of them could be attached to a wire on one side of the condenser, and half to a wire on the other side. Then he placed the other wooden block on top of the whole thing, passed the four screws through, one at each corner, and tightened them up evenly. This squeezed all superfluous paraffine from between the plates, and held the whole assembly very securely and neatly.
    "That looks fine so far," said Jimmy, critically. "But how do you mean to connect up all those tabs on the plates?"
    "I guess about the only way will be to solder them," replied Bob. "I used to have a soldering iron around here somewhere." He rummaged in the big drawer under the bench and soon produced the iron, which he then proceeded to heat over a gas flame.
    Said Bob, rising to get the soldering iron. "Whew! but this is hot now, all right. I'll let it cool a bit, and get the condenser ready for soldering."

CHAPTER  XIII

THRASHING  A  BULLY

    STRIPPING a length of copper wire, Bob nipped off two short lengths with his pliers and fastened them to opposite sides of the condenser with small staples. Then he brought all the tinfoil plate terminals on each side in contact with the wire on that side, and connected the terminals with their respective wires with a small drop of solder on each. Then he produced a roll of ordinary bicycle tire tape and wound the whole thing neatly in this, leaving only the ends of the two copper wires projecting a distance of perhaps a quarter of an inch.
    "There!" he exclaimed, "we can solder our other wires up to them when we come to connect up the set. It isn't very fancy, but it ought to do the work."
    "Gee, Bob, you must have been studying up on this," said Jimmy. "To look at your work, any one would think you'd been doing this all your life."
    "I did look it up after you fellows went home last night," admitted Bob. "This condenser isn't made just the way they say, but the principle is the same, and I guess that is the main thing."
    "We won't worry about how it's made if it only works," said Joe, "and I guess it will do that all right."
    "We'll hope so, anyway," said Bob. "But there's only one way to find out, and that's to hook our set up and see if we get signals through. And if we do--oh boy!"
    "I'll bet it will work like a charm," said Jimmy enthusiastically. "We haven't got to make much more now, have we?"
    "We've got to make a panel and mount all these inventions on it," said Herbert.
    "That won't take very long," said Bob. "Of course, we can't do it to-night, but to-morrow's Saturday, and if we get started early we may be able to fix things up so that we can hear something to-morrow night. Saturday night is the time they usually send out the biggest number of musical selections, and if we have luck we may be able to listen in on them."
    "Wow!" exclaimed Herb. "Won't that be the greatest thing that ever happened? You can't start too early to suit me."
    "Nine o'clock's early enough," said Bob. "Everybody come around here then and we'll make things hum. There's still plenty to do, but we ought to get it finished before that."
    The boys were so excited at the prospect of actually operating their set the following evening that they could hardly sit still two minutes at a time. They laughed and joked and speculated on what would be the first thing they would hear through the air, and finally Bob's guests started home in an hilarious mood.
Pages 119-153:

CHAPTER  XIV

ON  THE  VERGE

    Said Bob, "Let's get to work on our panel and see if we can't get things hitched up in time for the Saturday evening concert. I'm crazy to get the thing actually finished now."
    "No more than I am," said Joe. "Let's go!"
    His three chums all felt very much at home in Bob's workroom, and knew where to find the various tools almost as well as Bob did himself. Jimmy was given the job of sawing a panel board out of an oak plank, while the others busied themselves with stripping the insulation from lengths of wire and scraping the bared ends to be sure of a good, clean connection. Bob also cleaned and tinned his soldering iron, in preparation for the numerous soldered joints that it would be necessary to make.
    "It seems to me you rest an awful lot in between strokes, Doughnuts," said Herbert to that perspiring individual. "Why don't you keep right on sawing until you get through? It seems to me that would be a lot better than the way you're doing it."
    "If you don't like the way I'm doing this, just come and do it yourself," was the indignant reply. "I'd like to see you saw through twenty inches of seven-eighths oak without stopping. You always seem to get all the soft jobs, anyhow. Whenever there's anything real hard to do, like this job, for instance, it gets wished on me."
    "That's because we know you like hard work," said Bob, laughing.
    "Well, I get it whether I like it or not," complained Jimmy. "But it's almost done now, so I'll finish it quickly and prevent any of you fellows having to do some real work."
    "Jimmy's certainly good at that, you have to admit it," said Joe. "I could just stand here all day and admire the way he does it."
    But for once the boy refused to rise to the bait, and kept doggedly on until at last he had a neat twenty inch square cut out of the big plank.
    "There you are, Bob," said Jimmy, panting. "Now see if you can't find some heavy job for these two Indians here."
    "I'd like to, first rate," laughed Bob, "but I guess you've about finished up the last of the hard jobs. Of course, we've still got to drill a lot of holes in that piece of wood, but that's easy enough."
    "If you give me your word it's easy, I'll tackle it," said Herb. "Where do we want the holes, Bob?"
    "I don't know yet," said Bob. "We've got to arrange the different parts on the panel first, and find out just where we want them before we drill a single hole. I don't want to have to change things around after we put holes in the board and spoil the appearance of it."
    He laid the board on the bench, and arranged the tuning coil, the crystal detector, the condenser, and the terminals for the head phone plugs in what he thought should be their proper positions, and then called for advice on this layout.
    "If anybody can think of a better way to set these things up, let him speak now or forever hold his peace," said he.
    "That looks all right to me," returned Joe, eyeing the outfit critically. "But we'll have to raise the panel up an inch or two so as to give room underneath for wires and connections, shan't we?"
    "Right you are!" exclaimed Bob. "There's another job for you, Jimmy. We'll have to have two cleats to go underneath and raise the whole business up."
    "Never mind whom I mean," said Jimmy. "Here are your cleats, so you can get busy and screw them on to the back of that panel. I'll lie down on the couch and watch you to see that you don't make any mistakes."
    "No danger of that," said Herb. "I couldn't make a mistake if I tried. Wait till I get hold of a screw driver and watch my speed."
    "You'll probably make a mistake without trying," said Jimmy, "but I suppose there's no use trying to give you good advice, so go ahead."
    However, Herb justified his modest estimate of himself this time, for he soon had the cleats strongly fastened to the back of the panel, raising it two inches, which gave plenty of clearance for wires and screw heads underneath.
    "That will make a better job of it, anyway," said Bob. "I was figuring on running the wires on the top side, but if we put them underneath it will look neater, although it will take longer to do it."
    "We might as well do it up brown now that we've got this far," said Joe, and the others were of the same opinion.
    The boys arranged the various pieces of apparatus to their satisfaction, and then drilled holes through and bolted them securely to the back. This also took a little more time than merely to screw them to the face of the panel, but made a more secure and lasting piece of work. They were still drilling holes and clamping down nuts when Mrs. Layton called down to tell them that lunch was ready.
    "Ah, this is the life!" sighed Jimmy, as he stretched out luxuriously on his back and gazed up at the cloud-flecked sky.
    "It isn't so bad," admitted Bob, biting on tender blades of young grass. "But I'd enjoy it more if we had our outfit together and working."
    "It won't take long to finish it now, do you think?" asked Joe.
    "Not unless we strike a snag somewhere," said Bob. "After we get everything assembled, we've still got to run our leading-in wire down to my bedroom. But I don't think that will take us very long."
    "By ginger, I just can't loaf around until we do get it working!" exclaimed Joe' springing to his feet. "Come on, fellows, let's get busy. We can take it easy after we have everything fixed up."

CHAPTER  XV

THE  FINISHING  TOUCH

    THE three chums set to work with a will, cutting, stripping, and soldering wires, and while the afternoon was still young they made their last connection and found themselves possessed of a real honest-to-goodness radio receiving outfit, not quite so beautifully finished and polished off as a set bought readymade in a store, perhaps, but still serviceable and practical.
    "Hooray!" shouted all three together, so loudly that the sound reached Jimmy, still lying on the grass, and roused him from his blissful slumber.
    "What's the matter here?" he asked a few moments later, coming sleepily down the stairs. "Is the place on fire, or what?"
    "No, but we've got the whole set together at last, and we thought we were entitled to a yell or two," explained Bob.
    "Gee, that's fine! I didn't mean to sleep so long. Why didn't you wake me sooner?"
    "You seemed to be enjoying that snooze so much that we hated to disturb you," said Bob. "There wasn't very much you could have done, anyway."
    "Well, I certainly feel a lot better," said Jimmy, with a prodigious yawn. "What's the next thing on the program?"
    "All we've got to do now is to hook up our leading-in wire and ground wire and we'll be all set," said Bob. "I've got a fine big table in my bedroom, and I was thinking that that would be a fine place to mount all our things and keep them together."
    This was agreeable to all concerned, so they repaired forthwith to Bob's room. This was situated on the top floor, and, as it happened, almost under the scuttle leading onto the roof. This made it comparatively easy to connect up with the antenna, as all they had to do was to bring the leading-in wire through the frame of the scuttle, drill a hole through the attic floor and the ceiling of Bob's room, and drop the insulated leading-in wire through. To make it perfectly safe, they surrounded the wire, where it passed through the scuttle and ceiling, with a fire proof asbestos bushing or sleeve. In this work they received some advice from Dr. Dale, who chanced to drop in.
    All this work took some time, and it was nearly dark when they had made all their connections, including the ground connection to a water pipe.
    On one corner of Bob's big table they had inserted a small knife-blade switch in the leading-in wire, so that the set could be disconnected from the aerial when not in use, or during storms so as to guard against lightning.
    When all was finished the boys viewed the result of so many hours of hard work and planning with mingled feelings of delight at its business-like appearance and apprehension that, after all, it might not work.
    "Gee, I'm almost afraid to try it," said Bob. "But we've got to find out what rotten radio constructors we are some time, so here goes," and he produced his set of head phones. So did Joe and Herb, but Jimmy was struck with a sudden unpleasant thought.
    "Great Scott!" he exclaimed. "I've gone and left my set home. I'll get it and come back as soon as I can," and he dived precipitately out of the room.
    "He didn't need to be in such a hurry," laughed Bob. "We could have taken turns with ours."
    "Well, let's connect up, anyway, and see if we can hear anything," said Joe. "There's no use waiting until Jimmy gets back. It won't take him a long while, and likely enough he'll be back before we raise any signals, anyway."
    "Well, pull up your chairs, and we'll plug in," said Bob, adjusting the ear phones over his head.
    "I saw in this morning's paper that the Newark broadcasting station was going to send out an orchestra concert this afternoon, and if our set is any good we ought to hear part of it."
    They all adjusted their ear phones and then drew up chairs and inserted the plugs in the spring sockets designed for their reception. They had connected four pairs of these sockets in parallel, so that all four head sets could be used at once.
    Now was the crucial moment, and the boys waited breathlessly for some sound to come out of the air to them.

CHAPTER  XVI

SWEETS  OF  VICTORY

    BOB set one of the sliders about at the middle of the tuning coil, and set the other--the one connected to the leading-in wire--about opposite. Then he adjusted the sharp pointed wire on the detector until the point was just touching the crystal. Still there was no sound in the ear phones, and the boys looked at one another in bitter disappointment. Bob moved the antenna slider slowly along the tuning coil, and suddenly, faint, but very clear, the boys heard the opening chords of an overture played by a famous orchestra nearly a hundred miles away! Sweet and resonant the distant music rose and fell, growing in tone and volume as Bob manipulated the contacts along the coil. The boys sat spellbound listening to this miracle, to this soul stirring music that seemed as though it must surely be coming from some other world. Hardly breathing, they listened until the last blended chords whispered away into space, and then looked at each other like people just awakened from a dream.
    Bob was the first to speak.
    "I think we can call our set a success, fellows," he said, with a quiet smile.
    "Bob, that was simply wonderful!" cried Joe, jumping up and pacing about the room in his excitement. "Why, we can sit here and hear that orchestra just as well as though we were in the same hall with it. It seems like a fairy tale."
    "So it is," said Bob. "Only this is a fairy tale that came true. I wish Jimmy had been here to listen in with us."
    "He's here now, anyway," said a familiar voice, and Jimmy burst into the room, puffing and blowing. "Does it work, fellows? Tell me about it."
    "I should say it did work!" replied Joe. "We just heard a wonderful selection played by a big orchestra. It must be the Newark broadcasting station, as they had promised a concert for this afternoon."
    "I missed it, then, didn't I?" said Jimmy, with a downcast face.
    "Yes, but they'll play something else pretty soon," said Herb. "Plug in with your ear phones, and maybe you'll hear something to cheer you up."
    "It will take quite a good deal," said Jimmy, "after hoofing it all the way to my house and back on the double quick. I'll bet that trip took ten pounds off me, if it took an ounce."
    Said Joe, "Hurry up and plug in here, so that we'll be ready for the next number on the program."
    "Oh, all right, all right," said Jimmy, adjusting his phones. "If I'm not ready, just tell 'em to wait."
    The absurdity of this idea raised a laugh, which was suddenly cut short as the first notes of a rousing march came ringing into the ear phones. Every note was true and distinct as before, with practically no interference, and when the last note had died away the boys rose and as though actuated by one impulse, executed an impromptu war dance.
    When they had quieted down somewhat, Bob rushed downstairs and brought his mother up to hear her first radio concert. She was rather incredulous at first, but when the first notes of a violin solo reached her ears, her expression suddenly changed, and when the selection was over she was almost as enthusiastic as the boys themselves.
    "That was simply wonderful!" she exclaimed. "I never imagined you would be able to hear anything half as distinctly as that."
    "I'll bet you never thought you'd hear anything over our home-made set, now did you?" accused Bob.
    Mrs. Layton looked a trifle guilty. "I never thought you'd get it working so soon nor so perfectly," she confessed. "But now that you have, I certainly congratulate you."
    They all listened for some time for something else to come in over the aerial, but apparently the concert was over, for they could hear nothing but a confused murmur, with here and there some fragment of a sentence coining out clear above the general confusion. This was probably due to the sending being so distant as to be almost beyond their range. Just before supper time they heard a message from a ship at sea, and Joe, Herb, and Jimmy could hardly tear themselves away to go home to supper. They finally got started, however, promising to return as soon as they could after supper, so as to be in time for the evening concert.
    After they had gone, Bob called up Doctor Dale, and told him of the successful outcome of their experiment. The minister was delighted.
    "That's great work!" he exclaimed heartily. "So the set works well, does it?"
    "Yes, sir, it certainly does," said Bob. "Of course it's not as good as yours, and we can't tune out interference very well. But it does all that I hoped it would, and more. I wish you could around to hear it when you get a chance."
    "I tell you what I'll do," said the doctor. "I have an expert radio man visiting me here this evening. How would it be if I dropped around some time during the evening, and brought him with me?"
    "Fine!" exclaimed Bob, delighted at the prospect of talking with an experienced radio man. "We'll all be looking for you, sir.
    Bob was delighted over the doctor's promise, and told his friends about it as soon as they arrived that evening. They were all equally pleased.
    "He can tell us just what we need to know," commented Joe. "You can dig a lot of stuff out of books, but lots of times just the question you want answered doesn't seem to be in them."
    The boys had just raised the Newark station, and were listening to the first number on the program, a soprano solo, when the minister and his friend arrived. He introduced the stranger as Mr. Brandon, and the latter immediately made himself at home.
    "I hear you fellows got your set working first crack out of the box," he said, as they were going upstairs. "You're luckier than I was with my first one, because I had a lot of trouble before I got my first signal through. I fooled around a long time before I found out what the trouble was, too."
    "What was it?" asked Bob.
    "I finally found that the water pipes were insulated from the street pipes, as they are in some houses, so that I really didn't have any ground at all, even though my ground wire was connected with a pipe in the bathroom. I might have been looking for the trouble yet if a friend of mine hadn't given me a tip what to look for."
    By this time they had reached Bob's room, and Dr. Dale and Mr. Brandon inspected the boys' outfit with great interest.
    "Pretty good for beginners, isn't it, Brandon?" said the minister at length, when they had gone over the thing at length and Bob had explained the way they had made the different units.
    "I should say so," acquiesced the expert. "They've made up one of the neatest amateur jobs I've seen in a long time. Let's see how it sounds."
    He and the doctor donned head phones, and Mr. Brandon manipulated the tuning coil and the crystal detector with a deftness that spoke of long experience. He showed the boys how they might get even clearer and louder tones than any they had yet obtained by adjusting the detector until the best possible contact was obtained with the crystal.
    "You could hear better with a more elaborate set of course," he said, "but you get mighty good results with what you've got. Of course, your range is limited to less than two hundred miles with this set, and your tuning range is limited, too. But you've made a fine start, and with this as a foundation you can go on adding equipment, if you like, until you have a first class receiving station."
    "Yes, and after we get a little more experienced we want to try our hand at sending, too," said Joe.
    "Well, that's a more complicated undertaking," said Mr. Brandon. "But there's no reason why you shouldn't, if you are willing to go to the trouble to learn the international code and take an examination. You have to be able to receive ten words a minute, you know, to get a license."
    "I suppose you're an expert both sending and receiving," said Bob.
    "I ought to know something about it by this time," said Mr. Brandon. "Uncle Sam has me working for him now as radio inspector, so I'm supposed to know something about it."
    "Mr. Brandon was with the aviation radio branch of the service during the war," explained Dr. Dale, "and he has seen radio telephony develop from almost nothing to what it is to-day."
    "Yes, it was the war that speeded up the growth of radio," said Mr. Brandon. "It revolutionized war in the air, and made it possible to control the movements of airplanes in a way that had never been dreamed of before."
    "You must have had some mighty interesting and exciting work," ventured Herb.
    "All of that," admitted Dr. Dale's friend, with a smile. "Once our whole station was wrecked by a bomb dropped on it from an enemy plane. Luckily, we all had time to duck out before the bomb landed, but there wasn't anything left of our fine station but a big hole in the ground and bits of apparatus scattered around over the landscape. There were very few dull moments in that life."
    "It doesn't sound very dull," said Bob, laughing.
    "I can assure you it wasn't," said the radio expert. "But in the case I was telling you about, our airmen brought down the fellow who had dropped the bomb, which made us feel a little better."
    "There's some interesting stuff coming in now," said Dr. Dale, who had been listening in at the receiving set. "They're sending out news bulletins now, and I'd advise you to listen for a bit. It's away ahead of reading a newspaper, I assure you."
    "Besides being easier on the eyes," grinned Mr. Brandon. "Let's hear what it's all about." Sitting at ease, they heard many important news items of the day recorded. There was a little interference from an amateur sender, but they finally managed to eliminate this almost entirely by manipulation of the tuning coil.
    "I know that fellow," said Brandon. "I was inspecting his outfit just a few days ago. He's got a pretty good amateur set, too. He's located in Cooperstown, not twenty miles from here."
    "My, you must know every station in this part of the country!" exclaimed Joe, surprised.
    "It's my business to know them all," said Brandon. "And if anybody takes a chance and tries to send without a license, it's up to me to locate him and tell him what's what."
    "It must be hard to locate them, isn't it?" asked Jimmy.
    "Sometimes it is," returned the radio inspector. I'm tracing down a couple now, and hope to land them within a few days."
    The little company had some further interesting talk, and then, as it was getting rather late, Dr. Dale and his friend rose to go.
    "I'm glad to have met all you fellows," said the radio expert, shaking hands all around. "If there's anything I can do to help you along at any time, Dr. Dale can tell you where to find me, and I'll be glad to be of service."
    The boys thanked their visitor heartily, and promised to avail themselves of his offer in case they found that they needed help. Then Bob saw the visitors to the door, and returned to his friends.
    "We're mighty lucky to have met a man like that who knows this game from start to finish," said Joe. "I'd give a lot to know what he does about it."
    "You never will know as much," said Jimmy. "Mr. Brandon is a smart man."
    In a few moments three tuneful whistlers were making their way homeward, with hearts elated at the success of their first venture into the wide field of radio telephony.

CHAPTER  XVII

THE  FERBERTON  PRIZE

    For the next few days the boys' radio set was in much demand. Of course all their immediate relatives had to listen in, as it is called, and they also invited many of their friends, both boys and girls, to try it.
    "Oh, it's too wonderful for anything," declared Joe's sister Rose. "To think of getting all that music from such a distance!"
    "Yes, and that splendid sermon Sunday afternoon!" exclaimed Mrs. Plummer. "I declare, if Dr. Dale doesn't look out they'll make it so nobody will have to go to meeting any more."
    "I've certainly got to hand it to you boys," was Doctor Atwood's comment. "I didn't think you could really do it. This radio business is going to change everything. Why, a person living away off in the country can listen in on the finest of concerts, lectures, sermons and everything else. And pick up all the very latest news in the bargain."
    A most interesting thing happened to the radio boys. The Representative in Congress of the district in which Clintonia was located, Mr. Ferberton, came out with an offer of a prize of one hundred dollars for the best amateur wireless outfit made by any boy in his district, and a second prize of fifty dollars. It was stipulated that the entire set, outside of the head phones, must be made by the boy himself, without any assistance from grown-ups. A time limit of three weeks was allowed, at the end of which time each set submitted was to be tried out by a committee composed of prominent business men and radio experts, and the prizes awarded to those getting the best results and making the neatest appearance.
    It may be imagined what effect this offer had on the four radio boys. The announcement was made at the high school one day, and from that time on the boys were engrossed with the idea of winning the coveted prize.
    "Just think of the honor it would be, let alone the hundred dollars," said Bob. "Whoever wins that prize will be known through the entire State."
    "I wouldn't care much who got the honor, so long as I got first prize," said Jimmy, avariciously. "What I couldn't do with all that money--yum, yum!"
    "Yes, or even fifty dollars wouldn't be anything to sneeze at," said Joe. "I give you fellows notice right here that you'll have to step mighty lively to beat yours truly to one of those fat plums."
    "Gee, you'll never have a chance," said Jimmy. "Why, my set will be so good that it will probably win both prizes. Nobody else will have a look in."
    "All you'll win will be the nickel plated necktie for frying," said Herb. "If you really want to see the winner of the first prize, just gaze steadily in my direction," and he grinned.
    "I'm not saying anything, but that doesn't prove that I'm not thinking a lot," said Bob. "Never leave little Bob Layton out of it when there's a prize hanging around to be picked."
    "It would be just like your beastly luck to win it," said Jimmy.
    "There won't be much luck about this, I guess," said Joe. "By the time the judges get through picking the winner, the chances are it will take a pretty nifty set to pull down first prize--or second, either, for that matter," he added. "There's a lot of fellows trying for it, I hear."
    "Well, as far as we four go, we all start even," continued Bob. "All that we know about radio we learned together, so nobody has a head start on the other." listening to radio
    One day the hardware dealer of whom they had purchased their supplies called Bob, Joe and Jimmy into his establishment.
    "Got something to show you," he declared importantly. "New box set, just from New York, and sells for only twenty-two fifty. Better than any you can make. Want to try it? There's a concert coming in from Springfield right now."
    "Yes, sir, we'd like to try it, and it's good of you to let us," answered Bob. "But we believe in making our own sets. That's more than half the fun."
    "Yes, but just wait till you hear this box set," urged the dealer. "Then maybe you'll want to own one. A professional set is always better than an amateur one, you know."
    The boys didn't know but they did not say so. They followed the man to a back room of his establishment, where the box set rested on a plain but heavy table.
    "There are the ear phones, help yourselves," he said. "I've got to wait on that customer that just came in."
    The three radio boys proceeded to make themselves at home around the table. They adjusted the ear phones and listened intently. There was not a sound.
    "Guess the concert is over," observed Doughnuts.
    "Wait till I make a few adjustments," put in Bob, and proceeded to tune up as best he could. He had been reading his book of instructions carefully of late, so went to work with a good deal of intelligence.
    "There it is!" cried Joe, as the music suddenly burst upon their ears. "Listen, fellows! They are playing Dixie!"
    "And it sounds mighty good," added Jimmy enthusiastically.
    "But no better than it would on our set at home," put in Bob, quickly.
    "Not a bit," added Joe, loyally.
    The three lads listened to another selection and then the storekeeper joined them.
    "Isn't that grand?" said he. "I'll bet you can't make a box as good as that."
    "Maybe we'll make something better," said Bob. "You come up to our place some day and listen to what we have."
    "Then you don't think you want a box?" And the shopkeeper's voice indicated his disappointment.
    "Not just yet anyway," answered Bob. "We'd rather buy the parts from you and make our own," added Joe. "Besides, we want to try for the Ferberton prizes."
    "Oh, that's it. Well, when you want anything, come to me," concluded the dealer.

CHAPTER  XVIII

FRIENDLY  RIVALS

    THE radio boys, Herb excepted, finally decided each to make his own set without any consultation with any of the others, and submit it to be judged strictly on its merits.
    "Three weeks ought to give us plenty of time," said Bob. "I'm going to do a lot of experimenting before I start in to make the real set. Of course, the one we've already got belongs to all of us equally, and you fellows know you can come and use it any time you feel like it."
    "Your mother will be putting us out if we spend much more time at your house," replied Joe. "It seems as though we have just about been living there lately."
    "Oh, don't let that worry you," said Bob. "You know you're welcome at any time. Besides, we won't have to put all our time on the new sets, either. We can have plenty of fun in the evening with our present one."
    The boys finally agreed to build their sets each by himself, and to say nothing about any features or improvements that they might incorporate in it. They were all enthusiastic over their chances, although they knew that the winners would have to overcome a lot of first-class opposition.
    Herb felt sorry at times that he had not started a set of his own, but his was an easy-going disposition that took things as they came, and while the other boys were studying all the books they could find on the subject and consulting Dr. Dale, Mr. Brandon having departed, he was listening to music and talk over the original set, and enjoying himself generally.
    "You go ahead and have all the fun you want now," said Joe one time, when Herb was teasing him about working so hard. "My fun will come later."
    "Yes--if you win the prize," said Herb. "But if you don't, you won't be any better off than I am, and you'll be out all your work besides."
    "Not a bit of it," denied Joe. "Even if I don't win either prize, my set will be returned to me after the judging is over, and I'll have that to show for my trouble, anyway."
    "Maybe you will, if they don't tear it all apart while they're looking it over," said Herb.
    "Aw, forget it," advised Joe. "If I don't get anything out of it but the experience, I won't think that I've wasted my time."
    "Well, that's the spirit, all right," said Herb, "Go to it. But you ought to have heard the concert I heard last evening while you slaves were working your heads off."
    "Yes, but when I get this outfit of mine working, I'll be able to hear everything a lot better than you can with the set we've got now," said Joe. "I've got some good kinks out of a radio magazine that I'm going to put in mine, and it's going to be a regular humdinger."
    "Oh, all right, all right," said Herb, laughing. "That's the very thing that Jimmy was telling me only this afternoon. He's putting a lot of sure fire extras on his set, too. I don't think there will be enough prizes to go around."
    "I don't care whether there are or not, so long as I get one," said Joe, with frank selfishness. "One is all I want."
    "That's probably exactly one more than you'll get," grinned Herb. "But you may astonish us all by working up something really decent. Funny things like that do happen, sometimes."
    " 'It's easier to criticize than to create,' " quoted Joe. "Likewise, 'he who laughs last, irritates.' If those two wise old sayings don't hold you for a while, I'll try to think up a few more for you."
Pages 212-214:

    The town hall that night was crowded, and many had to be content with standing room. Upon the platform were numerous wireless telephone sets that had been received for the competition.
    Mr. Ferberton himself presided at the gathering. He made a most interesting address, in which he dealt with the wonders of wireless and gave a review of its latest developments. His own set, which was one of the largest and most powerful the radio boys had ever seen, had been installed on the platform with a large horn attached, and for an hour and a half, while waiting for the prizes to be awarded, the auditors were regaled with a delightful concert.
    In the meantime, a committee of three radio experts had been examining the sets submitted in competition. They subjected them to various tests, taking into account the care displayed in workmanship, the ingenuity shown in the choice of materials, and the clearness of tone discerned when each in turn was connected with the aerial and put to a practical test. The choice was difficult, for many of them showed surprising excellence for amateurs.
    At last, however, the awards were decided on, and Mr. Ferberton, holding the list in his hand, advanced to the edge of the platform. The silence became so intense that one could almost have heard a pin drop.
    "The first prize," he said after a few words of introduction, "is awarded to Robert Layton."
    There was a roar of applause, for no one in town was more popular than Bob.
    "The second prize goes to Joseph Atwood," continued Mr. Ferberton, and again the hall rocked with applause.
    "If there had been a third prize," the speaker concluded, "it would have been awarded to James Plummer. As it is, he receives honorable mention." And Jimmy too had his share of the cheering and hand clapping.
    Long after the lights were out and the audience dispersed, the chums sat on Bob's porch, elated and hilarious.
    "I'm the only rank outsider," grinned Herb. "I take off my hat to the rest of the bunch. You're the fellows!"
    "You needn't take it off to me," laughed Jimmy. "I got only honorable mention, and there isn't much nourishment in that. Not half as much as there is in a doughnut. I could have used that money, too."
    "What are you two bloated plutocrats thinking of?" asked Herb of Bob and Joe, who had let the others do most of the talking.
    "Radio," replied Joe.
    "The most wonderful thing in the world," declared Bob.

THE  END