E-text prepared by Al Haines



AROUND THE WORLD IN TEN DAYS

by

CHELSEA CURTIS FRASER

Author of "Work-a-Day Heroes," "Secrets of the Earth," "Boys' Book of Battles," "Boys' Book of Sea Fights," "The Young Citizens Own Book," etc.



The World Publishing Company Cleveland, Ohio ——— New York City

Copyright, MCMXXII, By The World Syndicate Publishing Company Printed in the United States of America



PREFACE

In the infancy of aviation, the early 1920's, no one dreamed that the close of the decade would see it firmly and permanently established—a leader among the nation's industries. Heavier-than-air flight is perhaps the most amazing contribution of the 20th century.

It is easy to thrill to the seeming marvels of our own times, but only the short-sighted thinker believes in the perfection of present scientific progress. The 300-mile-an-hour airplane which Fraser conceived in this book for the speed of the Sky-Bird II was little more than so many words when he wrote it. . . . today we have 400-mile-an-hour fighting planes. Today we have in this country an intricate highway system, but perhaps within your own lifetime our highways, and the automobiles which skim over them, will be laughed at as obsolete and useless.

Thus it is that "the seemingly impossible of the fiction of today becomes outdone by the facts of tomorrow," as the author aptly phrased it.

In 1920 the idea of going around the world in ten days was as preposterous as that projected by Jules Verne in 1873 when he wrote Around the World in Eighty Days. But time has a way of hurling ridicule back as effectively as a boomerang. For we have seen and marvelled at the shattering not only of the mythical eighty-day record but even the ten-day record, as progress wends its ceaseless, ambitious, difficult and almost fantastic way through the years.

And so it will be gratifying and, no doubt, amazing to many to read this book and realize the advancement made in aviation since this story was written by Mr. Fraser, and how many of the ideas he prophesied for airplane advancement that have materialized in less than a score of years.

Around-the-world flyers, even the most recent, have all flown more or less northerly routes, not following the equatorial belt, which is, as we all know, the earth's greatest circumference. It is this course that our four young heroes take in Sky-Bird II, a plane designed and constructed by themselves, containing many features that aeronautics now takes for granted, and some not yet realized, which are, nevertheless, "within the scope of mechanical science," as Fraser says.

So, it is our opinion, young readers, that in addition to enjoying an exciting story, you will benefit by carefully reading the technical passages, and in doing so, learn to observe your present-day surroundings with a greater perspective—thus adding infinitely greater interest to your view of the world today!

THE PUBLISHERS.



CONTENTS

CHAPTER

I PAUL AND BOB II THE BROTHERS' INVENTION III THE SUCCESSFUL MODEL IV PLANNING A BIG AIRPLANE V AN AIR RACE FINISH AND A CHALLENGE VI THE MISSING BLUE-PRINTS VII WHO'S AT THE WINDOW? VIII THE SKY-BIRD II IX THE TEST FLIGHT X FINAL PREPARATIONS XI OFF FOR PANAMA XII FIGHTING A DEVIL-FISH XIII THE STRANGE AIRPLANE XIV A FAMILIAR FACE XV THE START XVI TRICKED BY RIVALS XVII ACROSS THE ATLANTIC XVIII AN IRRITATING DELAY XIX SAVED BY THE SEARCHLIGHT XX A JUNGLE ADVENTURE XXI THE DOUBLE LOOP XXII ABOVE THE CLOUDS XXIII BOMBED BY ROCKS XXIV RIDING AN AIRPLANE'S TAIL XXV ENGULFED IN A VOLCANO'S DUST XXVI IN AUSTRALIA XXVII PAUL VERSUS PETE XXVIII A MIX-UP IN DATES XXIX A FLYING RESCUE XXX AN ALARMING DISCOVERY XXXI THE FINISH



Around the World in Ten Days

CHAPTER I

PAUL AND BOB

"Did you say this big Air Derby around the world takes place this coming summer, Bob?"

"So dad told me at the breakfast table this morning, Paul. The plans have just been completed. He said full details would be in to-day's papers."

"And the afternoon edition is out now, for there's a newsie just ahead of us who is calling out the Daily Independent. That's your father's newspaper, too."

"It will be in there sure pop, Paul."

"Then I'm going to get a copy right now."

The two youths, who but a few moments before had come out of the broad doors of the Clark Polytechnic Institute along with a noisy throng of other students, paused when they reached the newsboy in question, and the taller of the pair bought a newspaper which he shoved into an inner pocket of his raincoat.

"We'll look at this in the car on our way home; a fellow can't do any reading in a storm like this," said the purchaser. "Let's hurry up a bit, Bob; I'm so eager to see what it says about that Derby that I can hardly wait to get to the station. Say, just think of it—a race around the world by air! Won't that be great?"

"I'll say so, Paul old boy! They ought to smash all existing records. You know that a man named Mears made the circuit in thirty-five days about seven years ago, and he had to depend on slow steam trains and steamships, aided by a naphtha-launch."

"That's true, Bob. Now that we have planes we ought to do a lot better. But the big oceans are the trouble for aircraft. The Atlantic has been crossed by Alcock and Brown in a Vimy-Vickers biplane, and also by our NC-4 flying-boat under the command of Lieutenant Read, and by the big English dirigible R-34; but the Pacific, with its greater breadth, has seemed so impossible that it has never been attempted."

"Why should it seem impossible?"

"Because they can't carry sufficient gasoline to cross the Pacific."

"But how about the islands?"

"The majority are not level enough to permit a landing, and others are too widely scattered. I have made quite a study of transoceanic flight since Harry Hawker and his partner, Grieve, made their unsuccessful attempt last spring to cross the Atlantic in a Sopwith machine, and for my part I can't see how this proposed Derby around the world can all be done by air, when no machine has ever yet been able to hop the Pacific."

"Well, Paul, we'll soon be at the station out of this storm, and then we can see what the paper says about it," was the philosophical conclusion of his companion.

With that they hurried on down the street, bowing their heads to ward off the sharp sleet as much as possible, while they gripped their school-books under their arms. They were a splendid-looking pair of young Americans, probably about eighteen years old, and the manner in which they swung along through the disagreeable drizzle, paying scant attention to it as they laughed and talked, showed them to be full of that boundless energy and gaiety of spirits which only perfect health and participation in athletics can bestow.

As Paul Ross and Robert Giddings approached the next corner, a young man with umbrella held low in front of him hurried around it and ran into a small Italian girl who was carrying a basket of fruit. She was staggered by the collision; her basket was knocked from her arm, and the oranges began to roll in every direction. The child broke into tears, but the cause of her misfortune only paused long enough to say angrily, "Confound you, you careless little beggar! Why don't you watch where you are going?" and hurried on his way.

"Say, Paul, did you see the way that swarthy-faced chap used that little girl?" cried Bob indignantly.

"I certainly did," was the no less indignant answer. "That lazy dog ought to be horse-whipped. Let's help the child."

Both boys fell to work with a will, rescued the escaping oranges, and tucked them back in their owner's basket. Then, with her grateful thanks ringing in their ears, they hurried on once more.

After they had gone a few steps, Paul Ross observed:

"Bob, I've seen that fellow before. That was Pete Deveaux. He used to be an Air Mail pilot on the same run as my brother John, but was discharged for drunkenness. Since that he has blamed John, and has written him several threatening letters, but is too cowardly to face him."

By this time they had reached the West 137th Street station of the suburban railroad which runs between the metropolis and various shore towns along the picturesque Hudson. They were just in time to catch a train, and found a comfortable seat in a rear coach. Then Paul brought forth the newspaper he had purchased. What they sought was found on the very first page, prominently displayed under a black-faced heading.

"Read it aloud, Paul," suggested Bob, and his friend proceeded to do so. The article was to the effect that the Aero Club of America, in conjunction with eminent aviation associations of the kind in Europe and Asia, had planned to stimulate interest in flying by holding an aircraft race around the world, which would start on the morning of July 4th. All contestants must be at least twenty-one years of age, and furnish an entrance fee of two hundred dollars. They might use any type of aircraft they chose, and could carry as many assistants as they wished, even utilizing trains or steamships, if not less than three-fourths of their journey were made by air; and they must stop at least once in each of four continents, and cross the Atlantic and Pacific oceans. Aside from these provisions, the selection of route was left entirely to each contestant. Then followed an imposing list of names of well-known flyers who, it was said, had signified their intention of competing. The article wound up with the statement that prizes aggregating a million dollars would be offered the winners.

"One million dollars!" exclaimed Bob Giddings. "Paul, old man, you'd better go in for this!"

Paul Ross's eyes sparkled, but the next moment he laughed and shook his head. "I surely would like to," said he, "but there are just three little things in the way of it."

"I suppose you need a machine for one thing?"

"Yes—and you must admit that's a good-sized item. Second, I need two hundred dollars to enter—something I don't happen to have, and something I know mother can't spare in such a hazard. Third, I need three years added to my age in order to be eligible."

"It does look rather hopeless for you, that's a fact," admitted Bob. "That second handicap might be overcome with my father's help, but the other two are real obstacles."

"It's mighty nice of you and your father, Bob, to wish to help me out in this fashion," said Paul; "but, as you state, the other drawbacks cannot be swept aside so easily. Perhaps later on, another 'round the world Air Derby will be pulled off, and I shall have a chance to enter it."

"Well, if you do, don't forget to count me in as an assistant," declared his friend. "Nothing would please me better than to make a trip like that with you, Paul."

"You certainly shall be welcome if the time ever comes. By the way, Bob, John and I have designed a new type of monoplane in our spare time, and for the past two months I have been busy making a three-foot model of this. I hope to finish it in a day or two, and I want you to go with me over to the old fair-grounds next Saturday afternoon and give it a test flight, if you will."

Bob Giddings was all interest at once, and plied his friend with many questions concerning his new model, many others of which he had in times past helped Paul fly with the keenest delight. The truth is, Paul Ross and his brother John, the latter a pilot in the government Air Mail service, were known all over the State of New York as makers of the best-flying model airplanes to be found anywhere. Ever since they were small boys in grammar school, the brothers had been constructing miniature monoplanes, biplanes, and seaplanes, which they had pitted against the best product of other lads in the neighborhood and surrounding towns, without once meeting defeat. Many of these specimens of youthful ingenuity they still preserved, suspended in bedroom and attic, where they were a never-ending source of interest to visitors at the Ross homestead in the outskirts of Yonkers.

The war had called John into the aviation service of his country, but Paul had still continued his experiments in making tiny airplanes, getting his friend Robert Giddings, who lived in a fine house on Shadynook Hill, to assist him in the flying. Thrown together by their mutual love for mechanics, and being in the same classes all through high-school, Paul and Bob had formed a strong attachment for each other, although the latter's home was far more pretentious than the former's, since Paul's mother was a widow in only moderately comfortable circumstances, while Bob's father was the editor and owner of the Daily Independent, one of the leading evening newspapers of New York City.

When John returned from the war it was with an incurable passion for flying, and within a few months he had re-entered the service of his country in the peaceful but dangerous work of carrying Uncle Sam's mails between Washington and New York in a big Martin bomber. He found that his younger brother's love for aviation had also developed, as well as his skill in constructing and flying model airplanes. Some of these recent ones were so novel in design and of such wonderfully ingenious workmanship, that John, who had won unusual honors as an aviator on the French front, was quite thunderstruck, and determined to encourage Paul's talents in this line in every way he could. Therefore, when the boy graduated from the Yonkers high school, and expressed a wish to take up a special course in aeronautical engineering at Clark Polytechnic Institute, John backed him up, and the mother, who would have preferred a less hazardous profession for her younger son, sighingly consented.

Paul's chum, Robert Giddings, had also gone to Clark Polytechnic upon leaving high school, his ambition being to become an electrical engineer. Thus both boys continued to be thrown in daily contact. It was their habit to go into the city to school each morning in the sedan with Mr. Giddings; but as he left the city late in the afternoon they usually took the train back.

As the friends now parted, Bob Giddings' last words were: "Don't forget to get that new model airplane done by Saturday, Paul. I'm crazy to see it."

"I'll be ready for you," was Paul's assurance; "but remember to keep this under your hat. It's to be a secret test, you know."

"Trust me," said Bob.



CHAPTER II

THE BROTHERS' INVENTION

When Paul Ross reached home that afternoon, it was to find someone there whom he had not expected to see. A tall, broad-shouldered young man, with a bronzed face and pleasant blue eyes, sat in the living-room, talking to his mother.

Paul rushed forward and joyfully grasped his brown hand. "Why, John!" he exclaimed, "I didn't expect to find you here!"

"Of course you didn't, Buddy," was the smiling response of the young man, who was wont to call his younger brother by this affectionate war-mate term. "The fact is, as I was just telling mother, two days ago I didn't know myself that I would be anywhere at this hour except speeding through the air between New York and Washington on my usual mail run in my trusty old Martin-bird. As it is, Buddy, it looks now as if neither you nor I would ever handle her controls again." There was a note of sadness in John's voice as he said this.

"Why, what's the matter, John?" asked Paul quickly.

"It's this way, lad: You know I told you and mother a couple of weeks ago, when I was here on my last regular lay-over, that Congress was talking about cutting a big slice out of the Air Mail appropriation, in order to reduce expenses. Well, the upshot of it all is, they made the cut, and not having enough money to carry on the service as it has been, the head of the Air Mail has ordered the abandonment of all flying divisions except the main line between New York and San Francisco. Only those pilots will be kept. So that's why I am here."

"Won't they take you on again soon, John?" asked Mrs. Ross.

"I fear not, mother," replied her elder son, shaking his head soberly. "Our field-superintendent did say that he would give me the first opening in the transcontinental line, since my records lead the bunch, and he even offered to displace one of the boys on that route and put me in his place, but—"

"But you refused," interrupted Paul, with conclusive pride in his big brother.

John grinned. "Well, put it that way if you like, Buddy," said he; "anyhow, as I said before, here I am. Some chap may quit or 'go West'—you know a round dozen of the poor chaps have been killed in the last year—and that may let me back in again. But I won't wait for it; I'll get after some of the commercial flying companies next week and see if I can't land a berth with them. I simply can't think of working on the ground. I guess I should have been born a bird, mother, instead of a human being, I love flying so much."

"I really believe you would be safer if you were a bird, John," asserted Mrs. Ross, with an uneasy smile. "Birds have no motors to fail them, no fire to ignite and burn them up, as our present airplanes. How many of your own unfortunate associates can lay their untimely deaths to either one of these causes! It was only the last time you were here that you were telling Paul and me about the terrible fall Howard Smith had because his motor stopped, and how his machine ignited, and how he was burned past recognition."

"I know," said the veteran airman; "those things will happen at times, mother, even with the most careful fellows. The time will come, I think, and very soon, when stalled motors can be restarted in the air, and when accidentally ignited fuel will burn itself out with no harm to either the machine or its occupants. The fact is, Paul and I have some ideas now as to how to overcome those very troubles, along with other improvements, and the first chance we get we are going to build an airplane along these lines and put it to the test, aren't we, Buddy?"

"We surely are," was Paul's enthusiastic response. "One of these fine days, mother, when we get our patents and sell them, you shall live in as fine a home as the Giddings's over on Shadynook Hill, and when you wish to go into the city to do any shopping, John or I will take you in a beautiful sedan airplane which will be safer than an automobile, and which will be guaranteed not to raise a dust or wear out tires."

Mrs. Ross laughed heartily at the glowing picture her second son had drawn, more because he spoke with such seriousness, and because John too wore a matter-of-fact look during the prophecy.

"Oh, I have some great dreamers here in this little family," she said, as she arose to resume her household duties. "We will hope that some of your dreams come true."

Her sons laughed good-naturedly; then Paul turned to his brother. "Come on down in the basement, John," he said; "I wish to show you our latest miniature model, the Sky-Bird. Another day's work ought to finish it."

John followed him downstairs. In one corner of the large basement was a good-sized workbench, lighted by two windows, and equipped with several neatly-arranged shelves, which now held a divers collection of chisels, bits, countersinks, etc. In a splendid oak cabinet attached to the wall above was a more extensive array of wood- and metal-working tools, some of which the brothers had bought with money earned at odd jobs when they were still small boys. Since, they had added to their set from time to time, as they needed this tool or that, until now few professional mechanics could boast of a finer assortment.

Suspended from a hook directly over the bench was a beautiful six-foot model of a racy-looking monoplane of peculiar and striking design. It was glistening in several coats of spar-varnish, and so light and delicate was its spidery frame that, as John reached out to take it in his hand, the exhalation of his breath set it swaying away from him.

"My word, it's a light boy all right!" exclaimed John admiringly, as he carefully took hold of the pretty thing. "That's just the feature we've tried to get, too, Buddy,—lightness." He looked closely at the long, graceful pair of wings, which were of an unusual thickness and a slight upward thrust like those of a bird, and which widened batlike as they ran back and joined the rear fuselage or body of the craft. "Have you put the helium-gas in these wings yet, Paul, as we planned? I see you have installed the valves. There's a valve in the after-fuselage, too."

"The wings and fuselage are both filled," said Paul; "that is what makes the Sky-Bird so light. If you had brought more helium the last time you were here, I could have pumped in twice the quantity, I think, and that would have made her so light she would rise of her own accord, I really believe. As it is, she now weighs less than a half-ounce. I had the scales on her yesterday."

John shared his brother's enthusiasm. "Fine!" he cried, with sparkling eyes. "Why, that's almost a neutral condition, as she is! Buddy, if we can apply this principle to a full-size machine—and I don't know why we can't—we shall have solved the biggest problem facing airplane designers to-day. With a machine weighing only a trifle more than her load of fuel and baggage, she will not only fly a lot faster but go a lot farther, with a given supply of fuel, than the present-day planes. And what is more, she could attain good speed with a single engine of reasonable power, where now many machines are handicapped with the burdensome weight of an extra power-plant. When will she be ready to test out?"

"I had planned to give her a trial in the old fair-grounds Saturday afternoon," said Paul. "I've asked Bob Giddings to go along."

"That's all right; Bob is a fine lad," said John; "but since you have set the trial for Saturday afternoon, and Bob's father is usually at home at that time, why don't you ask him to view the affair also? I'm sure he would enjoy it. He's a great sportsman, you know, like most newspaper men, and considerably interested in aeronautics."

"I had not thought of it; I'll do it," was the prompt response of Paul. "But we must warn him to silence, John. Whatever happens, we don't wish this to get into the Daily Independent."

"I'd say not," rejoined the former Air Mail pilot sententiously. "Mum's the word; we've got something here, Buddy. Unless I'm greatly mistaken we'll be consulting with the Patent Office at Washington much sooner than little mother anticipates." He poked Paul in the ribs as he spoke, and both young men gave vent to a low chuckle of intense satisfaction. It was an even greater pleasure to look forward to surprising their mother than to astonishing the world and winning its plaudits.

As good an airplane mechanic and flyer as John Ross was, his younger brother was little behind him in the matter of skill in handling a modern machine. It had been John's habit to return to Yonkers every two weeks for a week's lay-off, as customary with other pilots in the Air Mail service. On these occasions he had arrived in his plane, and during the term of his stay had often taken Paul up into the air for pleasure flights, as well as his chum Bob Giddings. Both boys were keen students, and it was not long before John could trust them to operate his big Martin with every confidence. Once, indeed, he and Paul had been caught over Long Island Sound in a bad storm, when the latter was in the pilot's seat, but Paul had brought the craft through like a veteran, winning his brother's unstinted praise and undying respect.



CHAPTER III

A SUCCESSFUL MODEL

Mr. Giddings was glad to accept the invitation to the trial flight. He and his son met the Ross boys at the old race-course Saturday afternoon. This immense, level field, with its one-mile oval and great empty sheds, at one time had been the county's boasted fair-grounds, but two years prior to the opening of our story it had been sold to Mr. Giddings, whose residence property stretched down the side of Shadynook Hill and joined it. New fair-grounds had then been established in another and more centrally located section of the district. In the old grounds the boys of the neighborhood now went to fly their kites and model airplanes, to hold impromptu bicycle and foot races, and to play tag and hide-and-go-seek in the cavernous sheds and around the numerous sagging stables.

It was late in the afternoon—just before dusk, when the winds would be at their quietest, and others not likely to be present—that our friends arrived at the field. There was not a soul to be seen. Paul, who had carried his precious Sky-Bird, freed it from the wrapper and held it up for Mr. Giddings to see. The night before he and John had put the finishing touches to the delicate structure by adding another coat of varnish and attaching the little rubber-tired aluminum wheels to the axle.

As Paul now held it up before the gaze of the great newspaper man, Mr. Giddings made no effort to restrain his admiration. "What a little beauty!" he cried. "Why, it's almost a perfect mechanical representation of a bird!"

"Isn't she a dandy, dad?" put in Bob, his eyes snapping.

"The Sky-Bird is really more of a bird than you may think, Mr. Giddings," declared Paul.

"Yes," added his brother John. "As you probably know, sir, a bird gets its great buoyancy from the fact that every bone in its body is hollow; in flight it fills these bones with a very light gas, which is formed by an action of its lungs in drawing in air. We have adapted this principle in the wings and fuselage of this little machine. They are airtight and filled with compressed helium-gas, which is non-inflammable and nearly as light as its highly volatile rival, hydrogen-gas."

"Hydrogen-gas is surely a dangerous commodity around fire," said Mr. Giddings. "I understand that when the big English dirigible R-34 came across the Atlantic last summer she was filled with hydrogen, and that her commander and crew all wore felt-soled shoes, so that they would not by any chance cause a spark when they walked over her metal floors and ladders just beneath her great bag."

"That is true," vouched John Ross. "One little spark reaching any of that stored hydrogen would have torn that great dirigible into fragments in one gigantic blast."

"We have handled recent newspaper copy containing mention of this new gas, helium; but I must confess I am in the dark regarding its nature and source," said Mr. Giddings. "What is it, anyway?"

"I will refer your question to Paul here," replied John. "He is the one who worked out this idea of using helium in an airplane and giving it the best properties of a dirigible without any of the dirigible's handicap of clumsiness and excessive wind resistance. He has been studying the properties of helium in school, also the flight of birds."

"Well, not to get into a tiresome discourse, as Professor Herron would say, I shall make this description very rudimentary," said Paul, with a smile. "During a total eclipse of the sun in India in 1868, Lockyer, a British astronomer, saw in the spectroscope a bright, yellow line of light around the sun. He called it helium, after the Greek word for sun. So much for him. Twenty-seven years later an element was found on earth in natural-gas in Kansas, which gave the same bright, yellow light viewed through the spectrum. The people, finding it would not burn, disgustedly let millions of barrels of this valuable element escape into the air, before a scientist told them that it was of untold value for balloon and airship purposes. It is thought the gas comes from radium deposits. It has never been found in any country except the United States, and only here in Kansas and northern Texas, where it occurs in sands from 14,000 to 16,000 feet deep. Our government is now securing about 50,000 cubic feet of helium per day, refusing to sell it to foreign countries, as it is all needed here, besides which it might be used against us in case of another war."

While Paul had been telling this, Mr. Giddings had been busy jotting something down in shorthand in a notebook.

"Pardon me, Paul," he said, looking up with a smile, "but this is so mighty interesting that, before I knew it, my old-time reportorial instinct had gotten the best of me, and I found my pencil at work. If you have no objection I should like to use this in the columns of the Daily Independent some time when it seems to fit in."

"No objection at all, sir," assured Paul.

Mr. Giddings began twirling the little twelve-inch two-bladed propeller at the nose of the model airplane. "What do you use for power to turn this propeller?" he asked, after admiring its perfect proportions for a moment. "I don't see any rubber-bands, such as Robert here has always used on his little machines."

John deftly lifted off the thin veneer hood of the airplane, and disclosed a very small four-cylindered rotary pneumatic engine of bewitching simplicity and lightness, which a baby could have held out in its pudgy palm.

"Paul has worked this little motor out of aluminum and brass and steel, from odds and ends," said John.

"With more or less help on the part of my elder brother," interjected Paul.

"Well, perhaps with a little," admitted John, "more suggestive than otherwise."

"What sets it going?" questioned Bob, curiously.

"The fuselage is divided into three sections," said Paul. "The forward section contains the engine here; the rear section is an airtight chamber containing helium; and the central section is also an airtight chamber, but contains ordinary air which has been pumped into it through a valve, using the bicycle pump John is carrying, until it is under strong pressure. When I turn this little valve an outlet is opened for the air to escape by a tube into branches communicating with each of these four cylinders. This works the tiny pistons, much the same as gas in a gasoline-motor, and they turn the little crank-shaft to which they are connected, and the crank-shaft in turn revolves the propeller on its end."

"Wonderfully simple!" Mr. Giddings exclaimed. "Wonderfully ingenious, too! Is this your invention, young men?"

"Partly, sir," replied Paul. "I understand, a company in New York is making a somewhat similar pneumatic motor for model airplanes, but John and I have made some radical improvements, to our notion. To-day's test will tell the story."

"Let's see the propeller spin 'er up once for the fun of it," suggested Bob. "It won't do any harm, will it? Dad and I will hold on to the airplane."

"Get a good grip then," warned John Ross, "for you will find there's a terrific pull to the little rascal. Paul and I tried her in that fashion early this morning down in the basement."

Bob and his father secured firm holds of the little Sky-Bird, one on each side, where the propeller could not strike them.

"Ready?" asked Paul, with a smile.

"Ready!" came the answer in unison.

Paul touched the little valve in the tank chamber of the fuselage. The next moment there was a quiver, and then the propeller began fairly to hum. A strong, steady gust of air began to blow in the faces of the Giddingses, while they had to hang on grimly in order to keep their little charge from jumping out of their arms and dashing away into the air. For fully three minutes the propeller continued to whirl with undiminished speed, then slowly it began to slow up, and finally stopped.

Both Mr. Giddings and his son wiped their hot brows as they handed the plane over to its makers.

"Whew!" said Bob, "that little mule has got a lot of pull to her."

"That she has," supplemented his father. "What sort of material is her frame made of?"

"Balsa-wood," said John.

"I never heard of that. Is it something new?"

"Yes,—to the arts of civilization, but I presume it has been used by the Indians of Ecuador, where it grows, for scores of years in the making of rafts, for which it is particularly well adapted. The tree looks much like our southern cottonwood, and the wood apparently has no grain. It has a surprising toughness and strength, and is a trifle over half the weight of cork, weighing only 7.8 pounds per cubic foot, while the same sized piece of cork weighs 13.7 pounds."

"Has this wood ever been used in constructing full-sized airplanes?" asked Mr. Giddings.

"I think not; but Paul and I believe it will be the coming wood for them," said John with enthusiasm. "We have used it plain on this machine. On a large airplane it ought to be reinforced with transverse sections of very thin spruce laid latticewise. That would add considerably to its natural strength, and increase the total weight very little."

"H'm, h'm!" said the great newspaper publisher, "this is very interesting, I am sure. Now let us see how this little affair behaves itself in the air."

Paul and his brother led the way out into one corner of the big field, so as to bring what slight breeze might spring up into the head of the airplane, explaining that machines without a pilot would keep a better keel under such conditions. John then carefully attached the bicycle-pump and recharged the air-tank, following which he took out his watch to time the flight. Mr. Giddings and Bob also took out their watches.

Paul set the little Sky-Bird down on the hard earth, in a spot where there was no grass or other obstacle, and with his finger on the air-valve, said: "Practically all rubber-band motors require starting the model airplane off by picking it up and tossing it away from you up into the air; but I think this machine will rise from the ground like a large plane, on account of its great lightness and unusual power. We will now see if I am right."

To tell the truth, this being the first time he had really tried the Sky-Bird in a flight, Paul was nervous as he turned the valve, removed his hands from the graceful little plane, and straightened up.

With a whirr like the wings of a partridge as it is flushed out of the grass by the huntsman's dog, the small machine shot forward a few feet over the smooth ground, then gracefully arose in the air and started away toward the opposite corner of the field. As it proceeded it continued to rise, until it reached a height of possibly ninety or a hundred feet, when it began to dip unsteadily.

"It's a gust of wind striking it," remarked John uneasily. "I hope she weathers it. If there was only a pilot in her now, he could——"

But even as he spoke the Sky-Bird seemed to recover her balance. Making a pretty circle, away she sped on her course, neither rising nor falling. Like a real bird she sailed onward, the noise of her whirring propeller now lost to her fliers, but her little pale-yellow silk wings against the blue sky plainly tracing her course for them. Paul was running after her now as fast as his legs could carry him. What if she should keep right on and go over the far fence?—he might lose the little darling!

That fence was a good half-mile away. For his pet to cover such a distance had not seemed within the bounds of probability to either himself or John at the start, for all of their great confidence in the flying powers of the new model. Now, as he kept on running and the Sky-Bird continued going with no sign of dropping, Paul really became alarmed for her safety in landing.

But just before it reached the boundary of the grounds, the youth saw that the airplane was slowly settling. Into the next field it flew, and the high board fence shut it from Paul's view as he came up to it. With a jump he caught the top boards, and scrambled up, springing down on the opposite side. It was to see his little machine just miss the branches of an oak tree and settle down into some long grass about a hundred yards beyond.

He found it undamaged, and hurried back to his friends in the fair-grounds, his heart beating jubilantly at the splendid results of the flight. He hugged the small airplane to his heart as if it were the most precious possession in the world, as indeed it was to him.

Mr. Giddings and Bob were loud in their praise, and John smiled in that quiet way that told the younger brother how well pleased he was. It was found that the Sky-Bird had passed over the lower fence in just one minute and three seconds, which was certainly good speed for such a diminutive contrivance. Several other flights were then made, all of which were equally successful. At the conclusion Bob Giddings was so excited that he could hardly stand still.

"Dad, isn't this little thing simply a wonder?" he exclaimed. "I'd give anything in the world if I could own a big fellow built on this principle. I'll bet it would pass anything now made."

His father looked thoughtful for a moment. Then, turning to the Ross brothers, he observed:

"Do you think, boys, that these features could be successfully applied to a full-sized airplane?"

"There's no doubt at all about it, to my mind, sir," replied John Ross. "That's the next thing Paul and I propose doing, although I expect we shall have a hard time getting enough money to meet the expense of materials. Of course we shall have the regular type of gasoline engine in place of this pneumatic arrangement, as this principle won't apply to big machines. I figure a 400 horse-power Liberty engine would carry such a machine two hundred miles an hour."

Again Mr. Giddings was silent a moment. Then he resumed: "John, I hear that you have been laid off from your Air Mail job. Is that right?"

"It is, sir."

"Well, then, I am going to make a proposition to you and Paul, and in a way Robert may consider himself involved, too, I expect. As you may know, Robert plans to be an electrical engineer, and Mrs. Giddings and myself are anxious to encourage him in every way we can. For some time he has been experimenting with wireless telegraph and telephone apparatus, and has made some sets of the latter which it seems to me are an improvement over anything now on the market, particularly a set for airplane use, which he has no means of properly testing out on account of the lack of the airplane. Now my proposition is just this: I will meet every expense of making a first-class full-sized airplane like the Sky-Bird, and pay you, John, a wage equal to that which the government allowed you as a pilot, if you three young men here will do the construction work secretly, and if Robert may be allowed a one-third interest in the venture, both in the plane to be made, and in any future benefits to be derived from the patent rights."

Of course the delighted John and Paul accepted this splendid offer, and Bob Giddings was so happy at the prospect of a fine big airplane in which to install his wireless apparatus that he actually hugged his father. They repaired to the Giddings home, and there, in true business form, a contract was drawn up and duly signed by all interested parties, with a notary's seal attached.

With a copy in their possession, the Ross boys hurried home, after having dinner with the Giddings family, to acquaint Mrs. Ross with the good news.



CHAPTER IV

PLANNING A BIG AIRPLANE

As planned, the much-talked-of Air Derby around the world took place from Mineola Field, New York, on the 4th of July. A great crowd had been attracted, owing to the extensive accounts of the affair in the big newspapers for the past several months, and a thrilling hush fell over the assemblage as, at high noon, one after another of the famous flyers took off in various types of aircraft. There were four big dirigibles, two of which started to cross the Atlantic at once, while the others took a northerly course with the intention of making the final hop from St. John's, Newfoundland, in accordance with several previous attempts of other aircraft. Besides these, seven heavier-than-air machines started, all making for Newfoundland also. Four of these were flying-boats, two were seaplanes, and the other was a double-propellered biplane.

Needless to say, the Ross boys and Bob Giddings and his father were present to see the machines off. They had arrived in the big automobile of the publisher, and were greatly interested in every detail of the departure. Several of the contestants John Ross knew, having met them at some time during his flying periods, and it gave him a chance briefly to renew old acquaintanceship and personally to wish them good luck on their long journey. Of course our friends would have given a whole lot to have been able to compete in the novel contest themselves, but that was out of the question.

When the last machine had disappeared from sight, they took their departure. Mr. Giddings left them at the office of the Daily Independent, following which Bob drove Paul and John out to some of the city's beautiful parks. Late in the afternoon they again stopped at the newspaper building and picked up Bob's father, thereupon turning the car in the direction of Yonkers. Altogether they had passed a very pleasant holiday.

"Robert tells me that your plans for the new airplane, the Sky-Bird II, are just about finished, John," remarked Mr. Giddings, as they sped northward along the smooth surface of Riverside Drive, with its beautiful greenery on the left and its fine residences at the right.

"Yes, sir," said John; "we have been devoting every spare moment to them. Of course a good many changes had to be made to adapt conditions from the little airplane to the big fellow, and to incorporate the extra pet features we all agreed upon were desirable. You know it never pays to start building an important and costly affair like an airplane without having every detail thoroughly planned out, and perfect working drawings in hand. I think Paul will complete the drawings early next week, including copies for accompanying the specifications when we apply to Washington for patent rights. As soon as the drawings are done, we will drop in at your home in the evening and show them to you."

"Good!" said Mr. Giddings. "I shall await them with great interest. I suppose as soon as I approve these drawings, you fellows will all pitch into the actual work."

"We surely will, sir," laughed Paul, while Bob, at the wheel in front, having caught some of the conversation, called back with energy: "That's just the size of it, dad."

"We have everything all ready," continued Paul. "The balsa-wood and spruce we ordered some time ago is on hand, and that will keep us busy until other needed materials arrive. We have repaired the big exhibition building in the old fair-grounds, put on new double doors and purchased a good Yale lock for them. John and I have taken our workbench and tools over there, and Bob has helped us rig up a nice little five-horse power motor and small handsaw, also a circular saw, home-made sand-drum, a small planer, and a boring-machine. That building is dry, and has lots of room in it for housing the new airplane as it grows to maturity. When cold weather comes we can easily install a couple of heating-stoves to keep ourselves comfortable and protect our materials and the machine from frost damage."

Mr. Giddings expressed himself as well pleased with these arrangements. As he noted the foresightedness of the young mechanics his confidence in them expanded.

"Don't hesitate to order anything you need, young men," he said warmly. "Have them send the bills to me. If my trust in you is misplaced, I am willing to stand the consequences. This is not only the best kind of a practical education for Bob, but it is good business training for all of us. Go ahead; go ahead!"

With such strong encouragement, is it any wonder that the three young men continued their operations vigorously? Not one of them scarcely wanted to stop long enough to eat and sleep, a la Edison; and as it was now summer vacation time, Paul and Bob were able to be with John all day long in the old exhibition building. Neighboring boys and even older people hung around the open doors to watch operations, but the builders were careful not to let them get close enough to gain any ideas which might be harmful to their interests.

On Tuesday evening of the week following the start of the Air Derby, John and his brother put on their best clothes and hied themselves over to the Giddings home. In Paul's hand was an envelope containing the precious plans for the Sky-Bird II—completed at last by the young draftsman, and ready to be shown to the financial member of the quartet.

When they were all seated in the Giddings library a little later, Mr. Giddings scrutinized the plans with every evidence of satisfaction written upon his strong features. Now and then he would ask a question, as Paul explained view after view and detail after detail. At length he pointed to an oblong object situated in the pilot's cockpit just under the dashboard. "What is that?" he asked, curiously.

"That is what John and I call an 'automatic pilot,'" answered Paul. "It is a new form of stabilizer, and made so as to overcome the defects of others which are on the market. A stabilizer should automatically keep an airplane on a fairly level keel no matter how air conditions are, even so steady that it will travel along on its course for a considerable distance with the pilot paying no attention to his controls, perhaps eating his lunch or reading his orders."

"A mighty useful contrivance," commented Mr. Giddings. "I should think that would also prevent lots of accidents in bad winds."

"It will—if it turns out as we expect," Paul remarked.

"Give me the full details of this," was the request. "Remember, I am not much of an airplane man."

"Well," said Paul, "you know, sir, that it is far more difficult to drive an airplane than to guide an automobile, not merely because you have two steering-gears or rudders to take care of, one for sidewise and the other for up-and-down travel, but also because there are movable planes in the wings of the machine, which have to be worked to tip or 'bank' it when making a turn or to keep it on an even keel when a gust of wind strikes it. The 'rudder' is the vertical plane at the tail of the machine, and is used for steering sideways, while the 'elevators' are the two horizontal movable planes just below the rudder, which are used for steering up and down. Similar planes to the latter, one situated in the back edge of each upper wing, are called 'ailerons,' and one or the other is raised or depressed according to whether the aviator wishes to bank to the right or left.

"The driver of an automobile has nothing to do but watch his steering-wheel, and be ready to touch a pedal when he wishes to slow up or go faster or stop. If he makes a curve he does not have to bank his machine owing to his comparatively slow speed; but the aviator, traveling much faster through the air, must do this, bringing his airplane to a steep angle if he makes a very short turn. If he does not calculate just right, he is likely to turn upside down and meet this death in a nasty fall.

"While the careful automobilist can always see the road in front of him and avoid rough spots or obstacles before he reaches them, the aviator cannot do this. It is true that he can see another airplane if it gets in his way, or a church steeple when he is flying low; but his greatest dangers are in the clear air itself, where they cannot be detected. He may suddenly drop into a 'hole,' which is really a downward current of air, or he may get a terrific bump when he strikes a rising current. A freakish whim of the winds may unexpectedly take away the air support from under one of the wings, and he will lurch and dip sharply to one side."

"And I suppose sometimes lose all control?" said Mr. Giddings.

"Yes, sir; that has very often happened," put in John. "A flyer friend of mine took a nasty tumble that way near Cleveland last year, breaking three ribs. It's a wonder he wasn't killed."

"The pilot is blind to these pitfalls," went on Paul. "He must control his machine largely by intuition and the sense of feeling, although the veteran airman, John says, can tell a good deal about what to expect from the nature of the earth or clouds below him."

"That's true," averred John. "The closer you are to the earth the more you will feel the 'bumps,' as we call them. They are a whole lot like the waves of the ocean, only invisible, and there will be one straight over every protuberance or depression of size in the surface of the earth. Mountains, hills, houses, lakes, valleys, rivers, forests, all cause bumps or holes in the air up above them. At one thousand feet they are pretty bad. At ten thousand feet they are scarcely noticeable. That's why most pilots prefer to fly high whenever they can."

"What causes the air to act in this way over such configurations?" propounded the publisher.

John looked helpless, and smiled. "You've got me there," he admitted. "I haven't had the opportunity to study aerostatics the same as Paul here. He can probably tell us."

"I'm not through my course yet," reminded his brother, "but I think I can answer that. The air surrounding the earth is a great belt forty or more miles through and is of an even thickness. As our globe sweeps through it, the lower stratum of air naturally sinks down into the valleys and like depressions. This action pulls down the upper stretches of air, thus creating what are termed 'air-pockets' or 'air-holes.' Very dangerous they are, too."

"That is plain enough," declared Bob. "Now, dad, let Paul go on explaining this 'automatic pilot.'"

"If the aviator is enshrouded in fog or tries to sail through a heavy bank of clouds, he is quite likely to lose all sense of direction," continued Paul. "He will not know whether he is banking or traveling on an even keel. Sometimes pilots have come out of a low cloud to find themselves dangerously close to the earth and in an awkward position, perhaps in a steep bank, a side-slip, or even in the terrifying nose-dive, and they have not had time to right themselves before crashing to earth. So you see that before flying can become reasonably safe, some way must be found of keeping the machine automatically on a level keel.

"To operate this stabilizer of ours all the pilot will have to do is to guide the rudder with his feet. The automatic pilot works the elevator and the ailerons. It takes care of 'bumps' and 'holes' and sees that the machine banks at just the right angle on the turns. This makes the operation of an airplane containing the stabilizer even more simple than running a motor-car, because you do not have to worry about going into different speed gears when climbing or descending. You will notice on this drawing that strong piano-wires connect the instruments with all the necessary controlling planes of the machine."

"Instruments?" interrogated Mr. Giddings. "I thought there was but one."

"No; there are two stabilizers, as you will see,—here, and here," was Paul's response, pointing his finger to the parts. "But, as each one is exactly like the other in its construction, only the one has been drawn in detail. The other stabilizer runs lengthwise of the cockpit and takes care of the elevator. Both of these are operated by compressed air, which proceeds from a little tank, right here. The tank is kept supplied by two tubes which lead into it, and each of which joins a small pump operated by a fan which is right here on each side of the fuselage where the onrush of wind will keep it humming as the airplane travels.

"Each equalizer has a bore in it half-filled with mercury, working a good deal like a carpenter's level. If the airplane tilts to one side or the other, the mercury will try to keep its level and will immediately flow to the high side of the bore. At each end of this mercury tube there are electrical contact points. As one becomes submerged in the mercury by a tilting of the plane, a connection is made whereby two electro-magnets are energized on that side. One of these magnets closes an exhaust-valve, and the other opens an inlet-valve, in the compressed air tank. At once air is forced into this double cylinder, which you see at the bottom of the stabilizer, filling the half which is to operate its own set of rudders; and a piston begins to work inside. The piston is connected to a toothed rack, as you will note, causing this to turn a sector engaging it. The control wires connect with this sector."

"Very clever arrangement; but I don't quite see how, in banking, the ailerons can be brought back automatically to a neutral position as soon as the turn has been completed," ventured Mr. Giddings.

"John and I have provided for that, while Bob is responsible for the electrical features I have just mentioned," said Paul. "You will notice that at the top of the mercury channel there is a dividing wall. A tube runs from the left side of this wall to the right wing of the airplane, also from the right side of the wall to the left wing. At the end of each tube there is what we call a 'venturi tube.' This is a kind of suction device operated by the wind. The wind which blows through the left venturi tube sucks the air out of the right-hand side of the mercury tube, and the right venturi tube sucks the air out of the left-hand side of the mercury tube. The stronger the wind, the greater the suction. Now, when making a turn to the right the left wing must travel faster than the right wing, and so there must be more suction in the left venturi. This produces a greater suction in the right-hand side of the mercury tube, which draws the mercury up on that side and down on the other, until the proper electrical contact is broken and the ailerons are returned to neutral position."

"Can the mechanism be thrown out of gear when desired? I should think such a feature might be desirable," remarked Mr. Giddings.

"Indeed it is desirable, sir," declared Paul. "No red-blooded pilot wishes to sit still and let his machine run itself all the time, no more than an automobilist. That would spoil all the sport. By merely disengaging the automatic pilot's wires here at the sector—the work of a couple of seconds—the airplane is ready for hand control."

"How much does it weigh?" was the gentleman's next query.

"A trifle less than a hundred pounds."

"That oughtn't to handicap an airplane any."

"Not a bit," said Paul.



CHAPTER V

AN AIR RACE FINISH AND A CHALLENGE

All in all, Mr. Giddings expressed himself as more than pleased with the drawings for the Sky-Bird II. At the end of the explanation, he put the papers back in the envelope, and asked:

"Have you another set of these drawings in ink, Paul?"

"Yes, sir; this is a copied set; the original drawings from which we will make our tracings and blue-prints are at home."

"You had better leave them there in a safe place, and work from your blue-prints in the old exhibition building at the fair-grounds, being careful to lock them up in your workbench every time you depart. I think you boys have a valuable thing here, and it is to your interest to keep others from knowing your plans or seeing the airplane until we have full government protection in the shape of patent rights. I shall turn this set of drawings over to a patent attorney in the city and ask him to make application to the Patent Office in Washington without delay."

The next morning all three boys, filled with new confidence and energy, met at the fairgrounds as soon as they had had their breakfasts. Paul carried two rolls of fresh blue-prints, which he and John had made while their mother was preparing the meal. One of these sets he gave to Bob to take home as his own special property, and the other one he spread out on the workbench for consultation as their needs required.

Up to this time no effort had been made to keep children and curious adults out of the grounds, but as their machine was now beginning to take on real form, they determined to do this. On a piece of board, Paul printed in large letters, "Private Grounds; Keep Out," and Bob nailed this up on the outside of the high board fence at the entrance. The gate itself they closed and barred on the inside.

"Guess that will be a sufficient hint to the grown-ups," said Bob with a grin. "If the kids climb over, we'll fasten a red flag to the front of our big hangar and paint 'Dynamite' in letters a yard long across the front of the building."

"Yes, and if that doesn't keep them away we'll turn the hose on them," laughed John.

Then they fell to work on the new airplane, applying themselves like beavers. All three boys had had the splendid benefits of manual training when they were in the public schools, and knew how to handle every machine they had set up. In addition to this, Paul and Bob were first-class amateur machinists, as their courses of engineering in Clark Polytechnic embraced the use of metal-working appliances of the latest design, as well as wood-working machinery, and they could have operated other machines had they needed them.

That evening the workers went back home tired but well satisfied with their progress. The next day the shavings flew again, and by the latter part of the week they had begun to assemble portions of the fuselage, using a waterproof glue which had been especially prepared for airplanes, and applying galvanized screws to withstand rust in damp atmospheres.

As the days went by, the boys, like almost everybody in the country, watched the newspapers eagerly for reports of the progress of the contestants in the big Air Derby around the world. Only four of the eleven aircraft to start had succeeded in getting across the treacherous Atlantic, two of these being dirigible balloons, one a flying-boat, and the other a Vickers-Vimy biplane. After landing on European soil one of the lucky airships came to grief in Italy in making a stop for fuel, but the driver had obtained an Italian Caproni plane and was making his way eastward with all haste. The other dirigible, commanded by Americans, had reached Teheran, Persia, where gas-bag troubles had compelled her crew to continue by train. About the same time the flying-boat, piloted by a Boston man, and the biplane, in control of two Englishmen, had reached Yokohama, Japan, within a few hours of each other. It was said that these contestants would wait there for the first steamship going to San Francisco, as they feared it would be impossible to fly across the great Pacific stretch of almost five thousand miles. Upon reaching San Francisco they planned to continue the journey to New York in airplanes furnished by California aeronautical friends.

The newspapers shortly after this announced the sailing of the rival parties at Yokohama. Storms and fog delayed the vessel. Finally she arrived at the Golden Gate, and then came the mad race across the North American continent in fresh airplanes. Near Cheyenne, Wyoming, the American plane was forced to the ground by engine trouble, allowing her competitor to get ahead several hours. This lead the American could not overcome, and the race ended at 5:15 o'clock on the afternoon of July 27th, with the English crew first and the American crew second. Three days later the belated French crew, who had met with mishap in Italy, came in, winning third prize.

The Ross brothers were at work in the hangar when Bob Giddings, who had gone into town on his motorcycle after some more screws, came back waving the copy of the Daily Independent containing this last account.

"Cartier and his bunch have arrived," he cried, springing from his machine. "Here it is on the first page. That accounts for all the prize-winners, and the excitement is practically over. The others will just lob in now—and they might as well." He tossed the paper to John. "Here, read it, you fellows," he said. "You can quit on the Sky-Bird long enough for that, I guess. I'll work while you lay off a few minutes."

Bob rolled up his sleeves, and John and Paul spread out the newspaper on the bench and interestedly read the article in question. As they finished, and were turning around to resume work, Bob observed:

"Dad's got a rattling good editorial on this Air Derby, if I do say it. Take a look at page 5 and see how he rips 'em up the back."

Shoulder to shoulder, the two brothers leaned over the bench and read as follows:

"AROUND-THE-WORLD" RECORDS

The world has just witnessed the finish of another effort on the part of mankind to circle the globe in record-breaking time. And once more the newspapers of the universe, and the sporting chroniclers, are registering a new record in this class of human endeavor. When, three days ago, the English team, headed by Chester Hodge, dropped out of a Curtis plane into Mineola Field, it was just 23 days, 6 hours and 15 minutes after the same crew had left that field in their Vickers-Vimy. This beats the former record of 36 days and some odd hours, made in 1913 by John Henry Mears, by the substantial margin of approximately 12 days. It is a big gain—a startlingly short time for encompassing the world as compared with the efforts of the past.

All of the three contesting crews to finish have broken Mears's record, and deserve great credit for their praise-worthy performance. The sponsors for this first great Air Derby around the world, the prominent aero clubs of this country and the Eastern Hemisphere, also deserve much praise for conceiving and promoting such a successful contest, and in posting such magnificent prizes.

But, in the interests of other similar tours likely to follow, this newspaper thinks it high time to declare itself opposed most vigorously to two fundamental features governing the competition just closed.

First, why was this contest called by its promoters an "Air Derby"? In our opinion, with rules allowing the use of other modes of travel as well as aircraft, the title is a decided misnomer. It should have been termed a "Go-As-You-Please Derby." Not a single one of these contestants accomplished the girdle by airplane alone; every winner took a steamship across the Pacific. Here's hoping that when another 'round-the-world contest is pulled off it will be tagged with a title which fits.

Second, when a specific record trip around the world is promulgated, is it scientifically correct to take a route which is approximately 30 per cent shorter than the actual circumference of the universe on which we live? In a foot race around a circular track judges do not let sprinters pick out their own course and "cut across lots" whenever they choose. Nor is it allowed in horse races, auto races, or any form of sport where time records are registered on curving courses.

The Daily Independent contends that beginning with Jules Verne's mythical hero Phileas Fogg, who in the story negotiated the journey in the improbable time of 80 days, back in 1872, every record-maker in the flesh and blood has followed northerly routes averaging the 30th parallel, thus traversing only about 16,000 miles of the world's actual circumference of 24,899 miles; and these records have gone down as true and complete accomplishments! But, because a wrongful practice, one misrepresentative of its purpose, has been carried on for almost a century, is it any reason for arguing that the process should continue in this advanced and enlightened day?

We say NO! It is time for this practice of around-the-world humbug and cheatery to stop right now. If it takes our fastest modern globe-trotters a whole year to go around the world by a route equal to or approximating the equatorial girth, then let it take them a year; for the sake of our pride and all that is good and sincere let us do our stunts on the square.

There are no records of an equatorial trip around the world. Who will be the first to establish one? Let us run a pen through all these short-cut records of the past, and turn a clean page for the entry of the first real journey around the fat old world's belt.

As Paul finished the editorial his heart was beating very fast. He was a true sportsman, and he realized the truth in the bold stand taken by the Daily Independent. His brother John was no less favorably affected by it.

"Bang me, if that isn't a good article!" said John enthusiastically. "Mr. Giddings may get a lot of criticism for this from a certain class of people, but he's taking the right course."

"He certainly is," approved Paul. "I had never thought of it before, but he points the error out so clearly that almost anybody ought to realize the need of a fairer route after reading his statements. Just as he says, it's never too late to correct matters which have been going wrong, no matter how long."

"I'd give anything I've got if I could be the first fellow to go around the world's belt," declared John, his brown cheeks glowing with deeper color at the thought; "I wouldn't care so much about beating these other chaps in the matter of time, just so long as I made a fair trail."

"Oh, John, wouldn't that be a great trip!" cried Paul.

"Say, look at here," broke in Bob Giddings, who had been near enough to overhear all of this conversation. His face was glowing, too, as he turned toward the brothers. "When we get the Sky-Bird II done, why couldn't the three of us pick out a new course around the globe in her? If she's as good as we think she will be, we could travel over any kind of land or water with her, and I think we could pick out islands in the Pacific so that we could cross that and make the entire journey by air."

"I believe this old ship could do it all right," said John, full of confidence and thrilled at the idea, as he stepped back and looked at the partly-assembled fuselage with a loving eye. "But, Bob, a trip like that would cost a lot of money just for gas, and you know Paul and I could hardly afford it."

"I'm going to speak to dad about it, anyhow," decided Bob; "he has been talking airplanes and world routes at home to mother and me for the last three months, and maybe he will be interested enough to back us up. He never stops at anything when he once sets his mind on it."

It was several days after this that Bob Giddings came to work with another newspaper in his hands.

"Things seem to be coming our way as fast as they can," he said, with a mysterious smile. "Take in what Mr. Wrenn, the editor of this paper, says in this framed insert on the front page."

John and Paul did as directed. The article was prominently displayed, and was to the effect that the Clarion disagreed very strongly with the attitude adopted by its contemporary, the Daily Independent, in regard to around-the-world routes. It declared that it was physically impossible by any mode of modern travel to follow a route along, or even within twenty degrees of, the equatorial line, and said it was a shame to assail the creditable records made in the past. In conclusion it stated:

If our esteemed sheet, the Daily Independent, feels so cock-sure of its position, why does it not do a little demonstrating? Why does it not organize an expedition, and prove its claim? This is all bunk! We are so sure of it, that we right now challenge our misguided friend to run us a race around the world on a course of his own selection, at any time, by any mode of travel he may choose. There! we have knocked the chip off of the Daily Independent's shoulder. Now let's see if our friend is really a bluffer or a fighter.

"You know the Clarion is a powerful evening newspaper, too," said Bob, when the Ross boys looked up from their reading. "It has always been a hot rival of dad's paper, but it never got quite so sarcastic as this before. Dad was good and mad when he read this last night. 'I'll show both the Clarion and the public whether I'm a bluffer or not,' he said to mother. 'If it takes the last cent I've got I'll organize an expedition to meet their challenge and prove my theory to be the correct one.' Then I woke up to our opportunity. I suggested to dad that if the Sky-Bird turned out as we hoped, she would be the very thing to pioneer such a route and give the Clarion people a race to make their eyes stick out; and I said John Ross was willing to head a crew including Paul and myself."

"What did he say?" asked John and Paul, almost in the same breath.

"Well, he gave a little gasp; his eyes snapped, and he quit walking the floor and sat down on the davenport. 'Robert,' he said, 'I'll think this matter over.' Then he lit a cigar and went to smoking. Dad seldom smokes except when he's got something heavy on his mind."

John and Paul now joined Bob in putting a knee-brace in the new airplane body. Somehow they had a feeling that the parts they were assembling with such care would one of these days go on a very long and arduous journey.



CHAPTER VI

THE MISSING BLUE-PRINTS

The Air Derby created interest all over the world. People in foreign lands talked about it and read about it in their newspapers, just as they had done in the United States and Canada. With the keenest kind of interest they had followed the reports of its progress and its finish. Several nations had hoped to have their own representatives come in first, only to be disappointed.

All this interested world pricked up its attention anew when the bold editorial of the Daily Independent was widely copied. As John Ross had predicted, and as probably Mr. Giddings knew before he wrote it, this particular article caused a furore of comment editorially and otherwise. Much of this,—indeed, it seemed the most of it—was favorable to the stand taken by the New York publisher. But when the rival sheet, the Clarion, arrayed its strong force in opposition, the conservative element of the public felt vastly encouraged, and many were the heated personal arguments as well as newspaper duels, which ensued. Aviators all over the land were particularly concerned, and it goes without saying that the winners of the late competition were all lined up with the Clarion contingent. This paper's challenge to the Daily Independent for a two-party race around the world on the Independent's own conception of what it considered a fair route awoke great joy in the hearts of the leave-things-as-they-have-been adherents. Few, if any of them, particularly the publishers of the Clarion, thought Mr. Giddings would ever take up the challenge.

Therefore, judge of the surprise of everybody, and the dismay of the Clarion staff, when a few days following the flaunting of its challenge, the front page of the Giddings paper contained the following, under a heavy black type heading:

THIS PAPER ACCEPTS THE "CLARION'S" CHALLENGE

A short time ago the Daily Independent in an editorial strongly criticized the methods or rather routes used in the past in making world tours for a time record, stating that such journeys had all been made unfairly, in that the routes adopted were about a third less than the actual circumference of the globe, and that in our opinion the only legitimate around-the-world record could be made by following approximately the equatorial line.

We expected a good deal of criticism, of course, when we came out thus boldly against a custom which had prevailed since the beginning of so-called "around the world" record trips. But we did not expect to be challenged to prove our sincerity by ourselves making such a journey in competition with our esteemed but rabid contemporary, the Clarion.

To show the Clarion that we are not "bluffing," and that we are perfectly willing to demonstrate practically any position we ever take, we herewith accept its challenge. Even now we have in process of construction a new type of airplane, by means of which we are confident we can fly approximately straight around the belly of this old world entirely by air. A little later we shall announce a time, place, and route, in our columns, and sincerely trust the Clarion will be satisfied with them.

It is quite unnecessary to say that Paul and John Ross read the foregoing article with the keenest pleasure the night they reached home from the hangar and found their mother just finishing its perusal. Naturally Mrs. Ross felt all of the average mother's anxiety at the thought that her sons would be exposed to the perils such a long journey would invite, but on the other hand she was very proud to think their talents had placed them in such an honored position. It had only been an evening or two before that Mr. Giddings, in company with his son Robert, had called at the Ross homestead, and after a long conference with the boys as to the suitability of the new Sky-Bird II for making a world cruise, had taken his departure with his mind fully made up as to how he should meet the rival paper's challenge.

A few days subsequently, Bob Giddings found, upon reaching home for lunch, that his motorcycle, which he was in the habit of riding back and forth to work, so that he could rush into town on short notice and get emergency materials for the airplane, had a flat tire. As he could not fix the tire then, he decided to walk back to the fair-grounds.

As he emerged from the big front yard of his home, he chanced to look toward town, and observed an orange-colored taxicab standing near the first crossing. This would not have especially attracted Bob's attention, except for the fact that a man sitting on the front seat was just at that moment pointing his index finger toward the Giddings' place, and a slender-looking man just descending from the cab was looking that way and nodding his head.

It seemed to Bob that he had seen the passenger before, but a second look made him think he must be mistaken; at least he could not place him.

"It's probably somebody to see dad. If so, he'll get disappointed, as dad won't get back from the city before evening."

Dismissing the incident from his mind with this thought. Bob hurried down the road, eager to reach the hangar and get to work again on the new airplane.

A few moments after he had passed the home of a youth he knew, he heard a familiar salutation, and turned around to wave his hand in a greeting to this friend, who had come to the front door. As he turned, his eye fell on a slender figure some distance behind, a figure which stepped behind a tree and stopped.

"Humph! that's funny," mused Bob. "It looks a lot like that fellow who got out of the taxi back there by our house; I wonder what he's up to, anyhow?"

He continued his way, but as he reached the fair-grounds gate and got out his key to unlock it, the whim to look back again seized him. As he turned, his gaze once more rested on the slender form of the wayfarer, who had crossed to the opposite side of the road, and who now, finding himself observed once more, promptly stopped and began to fuss with his shoe-lace.

"Say now, this is funny!" ejaculated Bob under his breath, vainly trying again to recall the identity of the lean figure and dark complexion. "I believe that chap is trying to shadow me. I wonder what in the dickens he really is up to?"

It was the second time Bob had asked that question of himself, but as he was a poor source of information just then, he was forced to pass into the fair-grounds and relock the gate in as mystified a state of mind as before he put the query.

A little later, when he reached the big hangar he whirled about again, as if half expecting to see the stranger still skulking behind him in the grounds. To his relief he did not detect this situation exactly, but he did see a dark face, which had been peering over the top of the highboard fence near the gate, drop down from view on the other side.

Bob gave a grunt as he passed into the hangar and took off his coat. "As I live, I believe he's up to some sort of mischief," growled the boy. And when, shortly afterward, John and Paul Ross appeared he told of his experience and repeated his suspicions.

"That is funny," asserted John; "Paul and I saw nothing of any such man when we came along, and we passed down the same road. Perhaps he mistook you for somebody else."

"I hope so, but I don't like his actions a little bit," declared Bob stoutly.

With that he picked up a try-square and pencil and began laying out some work for Paul to cut on the circular saw, while John busied himself at the boring-machine in putting a hole through the center of the big twelve-foot balsa-wood propeller which a little later would be reinforced with a thin jacket of a new metal called "salinamum," which was made chiefly from salt but whose fused components made it as light as aluminum and stronger than tool steel.

Soon the queer actions of the stranger were quite forgotten in the deep interest of the three young men in their work. With the prospect of a world tour before them if the Sky-Bird turned out well, they now had more incentive than at the beginning to build the machine with the utmost skill and attention to every detail. Some changes, calculated to make the craft better adapted to the peculiar conditions she would be likely to meet in such a varied temperature were put into effect, but on the whole they found their original plans so well laid that no important features seemed to require modification or abandonment.

But if the man who had followed Bob dropped out of their minds the rest of that day, he was soon to occupy a prominent place in their thoughts. For the very next morning, when Paul and John arrived at the hangar, they were met at the door by a very agitated Bob Giddings.

"Fellows, what do you think has happened?" cried Bob, clearly very much excited. Without giving his friends time to answer the question he blurted out: "Somebody got in here last night and stole our plans!"

"Stole our plans!" reiterated Paul and John in the same gasp.

"That's it," said Bob,—"stole the set of blue-prints we have been working from. What's more, they must have seen the airplane before they got out. I went to take the plans out of the bench drawer here where we have kept them locked up, and there was the drawer wide open, the lock picked, and the drawings gone. I'll bet a herring we can thank my dark-skinned shadow of yesterday for this little visit!"

"It does look as if he might have had something to do with this," agreed John soberly. "I wonder how the rascal, whoever he is, could have gotten in the building. There's a heavy Yale lock on the doors."

"The doors were locked all right when I came this morning," vouched Bob. "I don't see myself how—"

"Here you are, gentlemen!" called Paul, who had stepped to a good-sized window near the head of the workbench. "Here's the fellow's private entrance!" And he pointed to where a heavy nail locking the lower sash had been forced aside, also to a series of indentations in the outer sill, where some prying tool had obviously been recently at work.

"It's a clear case of theft, that's sure," observed John; "and since its only our plans that have been taken, it goes to show that this chap is very much concerned about this new airplane."

"Perhaps he wishes to beat us out in getting the patent rights," Bob hinted darkly.

"No, I don't think it's that," differed Paul; "our application was sent in to Washington some weeks ago, and you know the first one to apply for a certain patent gets the attention."

"Well, then, he could use our plans and make and sell airplanes of their pattern, couldn't he?" asked Bob, whose ideas of patent laws were still a little vague.

"Not at all; if he did we could sue him for infringement," was Paul's answer. "The only way he could profit by this theft, so far as I can see, would be to construct a machine for his own private use, or to give to another person. We could not touch him for that."

"And that would be bad enough for us—if such a machine were used against us in this proposed race around the world, wouldn't it?" demanded Bob Giddings.

Paul and John Ross looked at him in dismayed astonishment. They had not thought of this contingency before.



CHAPTER VII

WHO'S AT THE WINDOW?

The making of a big airplane is a good-sized job. Especially is this the case with the first airplane made up from new plans. And when the job has to be done by no more than three young men, it becomes an unusually formidable task.

The loss of the blue-prints did not hold up the progress of our friends in the least, as it was only the matter of fifteen or twenty minutes' work for Paul to make a new set from the tracings he had at home; but there were unexpected difficulties met here and there in the constructive work, as is always the case in large mechanical undertakings of an original nature, besides which the young builders ran into the usual delays caused by slow deliveries of parts and materials from distant dealers and manufacturers; and sometimes the railroads were tardy in transporting shipments.

All in all, the summer slipped away only too quickly, and it came time for Paul and Bob to go back to school again with Sky-Bird II not more than half finished. It is true that the long fuselage of the craft was done, with its graceful curves and splendid, roomy, enclosed cabin, accommodating five persons; but all concerned were a little disappointed that more progress had not been made. Mr. Giddings had been quite a frequent visitor at the fair-grounds all through the summer, lending a voice of encouragement throughout the operations. He looked really concerned, however, when Paul and Bob had to return to Clark Polytechnic Institute for the new term of study.

"This is rather hard on us, isn't it, boys?" he observed, with a light laugh in which he unsuccessfully tried to conceal his anxiety. "Here we are with a half-completed airplane, a race staring us in the face for next summer, and two of our workmen snatched away for the whole winter by the inexorable demands of school life, leaving only one lone fellow to finish the job."

"We'll be able to work Saturdays, dad," ventured Bob, trying to wedge a little bit of cheer into the gloomy prospect.

"And evenings. I'd be willing to work after supper every night for a couple of hours," proposed Paul.

"You won't do any such thing," came the firm answer. "While you are at school you two fellows need your evenings for rest and study, and your Saturdays for the school-team sports. Only when there isn't a game on in which you are a contestant will I allow you to help John on the machine—even if it isn't finished for five years. I have been thinking this situation over for some time, for I have seen it coming," went on the great publisher after a moment's pause; "and I have come to the conclusion that the best thing I can do to hustle our ship along is to call in another workman on the job, some chap we can trust and who knows how to handle tools. In fact, if he were a regular airplane mechanic it would be all the better."

John Ross spoke up at once. "Mr. Giddings," he said, "I think you have the right idea. Bob and Paul can't help me much from now on, and if we take that trip around the world next summer this machine must be done some weeks ahead, so that we can have a chance to test her out and tune her up. Now, it happens that Paul and I have a cousin—Tom Meeks—who is about my age and who flew in the same squadron with me over on the French front during the war. I will vouch for Tom's ability as a mechanic and flyer, also as to his trustworthiness. It happens my mother just received a letter from Tom's folks in Illinois the other day in which she said the factory had closed down in which he was working and he was out of a job."

"And you think this Tom Meeks would be willing to come up here, then, and help you this winter for the salary I am paying you?" questioned Mr. Giddings with interest.

"I think he would, sir."

"Then write to him immediately, and tell him to come right on."

In less than a week a strapping big young man, suitcase in hand, got off the train at the Yonkers depot, and was warmly greeted by his cousins, Paul and John Ross, who then introduced him to Bob Giddings. Bob had been so eager to see the new helper on the airplane that he could not wait for a later meeting with him. He took instant liking to the jolly newcomer, who seemed to be ever smiling, and after a short exchange of conversation with him hurried home to tell his father what a splendid fellow Tom Meeks was.

Tom was domiciled in the Ross home, to which he had been a visitor in other years, and of course for the rest of that evening was kept busy visiting with Mrs. Ross and looking at the numerous miniature airplanes of Paul's. His praise of the little Sky-Bird, and particularly of the drawings of Sky-Bird II was very strong, and when he went to the fair-grounds the following morning with John and actually saw what a fine-looking ship the big craft was, he was stumped for words to express his full admiration.

Then while John and Tom went industriously to work, Paul and Bob rode away to Clark Polytechnic in New York with Mr. Giddings. Just before starting into the city that morning, the newspaper man had met Tom, and there was little doubt that he was well pleased with this addition to his force of workers. Of course Paul and Bob were sorry to have to interrupt their labors on Sky-Bird II, but there was no help for it, and there was some consolation in the thought that undoubtedly their instructors would let them work on some of the airplane's smaller parts as a portion of their school mechanical practice. This supposition indeed proved correct, and as the fall days passed they found the two student chums not only partaking with full spirit in the sports of their comrades, but also contributing in no small measure to the progress of the work on the new airplane.

As a rule, Paul and Bob managed to stop in each Saturday for at least an hour or so to lend some assistance to John and Tom, and when there were no school contests on, they spent practically the entire holiday in the hangar.

The cool days of November soon compelled the boys to install a couple of heating stoves in the big building, and after that the place was warm and cheery throughout the working day, no matter how blustery and nippy the weather. At night the coals were carefully banked with ashes, to keep up a fair degree of warmth until the following morning.

Up to this time nothing had been seen of any suspicious person lurking around the premises, but one afternoon late in the month, when Tom Meeks was working alone in the hangar and John had gone to town after some bolts, Tom thought he heard a strange sound at one of the two windows near the workbench.

Turning quickly from the wing-strut which he had been setting in place, Tom faced the window just in time to see a swarthy-looking countenance, adorned with a toothbrush-like mustache, pulled out of range. The mechanic had been informed of Bob's experience with the man who had evidently followed him to the grounds during the summer, also of the blue-prints which had been stolen, and now as he observed the similarity in looks between this eavesdropper and the reported shadow of Bob, he became quite excited.

With that lack of coolness and presence of mind characterizing a more reserved temperament, the impulsive Tom rushed straight up to the window, and peered out. Of course he could see nothing, for the peeper had been cute enough upon finding himself observed to keep close to the side of the building as he moved swiftly toward its rear.

Tom now seized the lower sash and tried to throw it up, so as to get a sidewise view. To his disgust he found it double-spiked, and realized that he had put that very second nail in himself upon first learning of the loss of the blue-prints.

"Huckleberry pie!" sputtered Tom, using his favorite expression when excited.

He whirled about and started for the door of the building. On account of the extensive size of the structure it was quite a little way to this. To make matters worse Tom dashed forward in such haste and flurry that he did not watch his step very closely; when he was about half-way to the door, his toe caught the protruding leg of an innocent sawhorse, and the next moment Tom Meeks and the sawhorse were both overturned.

"Huckleberry pie!" gasped the big fellow. His right shin hurt like fury, but he would not stop to examine it, and covered the remaining distance to the door in very ludicrous limping jumps. Dashing around the front of the building, he reached the corner which gave him a view of the side.

Not a soul was in sight. Not to be outdone completely, Tom hurried along the side of the building. As he came near the rear end he saw a slender figure just clambering over the highboard fence of the field in the rear of the hangar.

Lame as he was, big Tom knew there was no chance of his overtaking the fleet-footed and cunning stranger, so he returned to his work very much crestfallen in spirit.

When John heard what had happened, on his return to work, he was considerably disturbed, and suggested to his comrades the advisability of placing a night-guard on the premises for a while at least, since this unknown enemy might make an effort some night to burn or irreparably damage the Sky-Bird. The others sanctioned this precaution, and thereafter took turns in watching, although this vigilance was apparently all for naught, as no suspicious character appeared.



CHAPTER VIII

THE SKY-BIRD II

"Well, Mr. Giddings, what do you think of Sky-Bird II?" asked John Ross, one memorable day.

There was a smile of deep satisfaction on John's own bronzed features as he put the question, a smile which was duplicated on the faces of his three co-workers—Paul, Bob, and Tom Meeks. It was the latter part of March, Easter vacation week for Paul and Bob, and the two chums had been working every one of the last three days helping John and Tom put the finishing touches on the big new airplane. And now this Friday morning it rested gracefully upon its own rubber-tired wheels, its great stretch of wings spread out as airily as those of a monster bird, its huge two-bladed propeller glistening like burnished silver, and its body running backward in a splendid symmetrical taper, to end at the well-proportioned tail. Sky-Bird II was done at last.

Mr. Giddings was so lost in admiration at the beautiful lines of the craft that he did not reply immediately to John's question. He had not seen it for almost two weeks, and in that time, under the onslaughts of the four boys, it had changed appearance in a striking way, numerous finished parts having been connected and paint and varnish having been applied.

"All I have to say, young men, is that if she performs anywhere near as well as she looks, I shall be thoroughly satisfied with the money I have invested thus far," declared the great newspaper man with an enthusiasm which he did not try to conceal. His eyes were shining, as he walked around the craft looking at it from all sides. He rubbed his fingers lingeringly over the smooth fuselage, and smiled quietly as he regarded the name "Sky-Bird II" lettered in large blue characters on her sides and underneath each long bird-like wing. Then he mounted a folding step and went through a neat door into the glass-surrounded cabin. This was deep enough to stand up in, and provided comfortable upholstered cane seats for the pilot and four passengers or assistants. All of these seats except the pilot's and observer's were convertible, forming supports for the swinging of as many hammocks, and in a small space at the rear was a neat little gasoline-burner, and over it a built-in cupboard containing some simple aluminum cooking ware.

"Well, I declare!" said Mr. Giddings in amazement at the convenience of things, "it looks as if you fellows hadn't left out a single item needed in a long and enjoyable cruise."

"There's nothing like being fixed up for all emergencies, sir," laughed John. "As you notice, we have everything for night-flying as well as day-flying. With such a machine as this there is no reason why a crew of four or five could not run nights as well as days, two operating while the others sleep in the hammocks. Cold foods can be cooked or warmed up on the gas-stove when needed, and the enclosed cabin protects all hands from the worst effects of bad storms."

"Wouldn't this glass break in a hailstorm?" asked Mr. Giddings. "It seems to be pretty thin."

"It is thin," said Paul; "that is to give it lightness. It might check some in a hailstorm, but it could not break out, as it is made of two layers of glass between which is cemented a thin sheet of celluloid."

"I think you had two Liberty motors here in the hangar when I was here last. I neglected to ask you the power of these, and what you need two for," observed Mr. Giddings. "I thought you said in the beginning that you considered one 400 horse-power engine of sufficient strength to carry this plane at a fast clip."

"It is this way, sir," responded John. "The regular big biplane of the bomber type carries two propellers with an engine for each propeller. If one motor fails them when flying, about all the other is good for is to make a landing with. By reason of the great lightness of our airplane one good 400 horse-power motor is all we need for pulling purposes. But suppose this should fail, as any motor might do? We could not continue, any more than the other fellow, and would have to volplane to the ground. Again, suppose we wished to fly continuously more than twelve hours? We could not do so, as such a steady run would heat the best motor and ruin it. These two Liberty motors, which we have, overcome all these troubles. Both are so arranged that a simple switch connects and disconnects either one with the propeller, and both can be put at work at the one time if needed in a bad storm. If one stalls, the other can immediately be thrown in and a forced landing obviated. Moreover, if we could get fuel when needed, with this arrangement I am safe in saying we could fly steadily day and night, resting one motor and working its mate, for a week or more."

"What is this?" As he spoke the publisher touched a peculiar-looking helmet hanging from a hook near the pilot's seat.

Bob laughed. "Why, don't you recognize the products of your talented son, dad?" he cried, as he took the object down and clapped it over his father's iron-gray head. "That's my new wireless telephone headpiece, and right underneath it here is the mahogany cabinet containing the sending and receiving instruments. You see, these two wires run from the plug up to the receivers, there being one receiver in each side of the helmet, right over your ear, pressing against the ear tightly by means of a sponge-rubber gasket."

"A man looks like a padded football player with this thing on," said Mr. Giddings with a smile. "Why is a helmet required at all?"

"We wouldn't require it so much with these motors, as they are equipped with a new kind of muffler which shuts out about four-fifths of the noise other airplanes get," explained Bob. "But for all that there are always noises in airplanes; for instance, they say the whirr of the propeller when it is revolving about 1450 revolutions per minute, or at the full speed of this one, makes quite a roar; so you see the need of the helmet to shut out all undesirable sounds possible. In ordinary planes the crew cannot talk to each other except by using phones or putting their lips to each other's ears and yelling at the top of their voices, according to what John and Tom tell me. But we don't expect to have that trouble in this enclosed cabin and with this new muffler working, do we, fellows?"

"I'm sure we won't," said John.

"Not if I'm any judge," grinned Tom.

"Can you talk with a ground station when you're flying, say a couple of miles high?" asked Mr. Giddings, examining a transmitter attached to a yoked wire support which his son slipped over his shoulders.

"Farther than that. With this particular vacuum tube, which will amplify sounds three or four times over any other I have tried, we expect to talk with ground stations or other aircraft at a distance of three thousand miles. Notice what a simple thing it is, dad," and Bob indicated a little glass bulb which looked a lot like an ordinary incandescent light, but which had a peculiar arrangement of wires and substances inside.

"Is the transmitter or receiver made just like the ordinary kind?" asked Mr. Giddings.

"Practically the same, dad. The wireless transmitter, like that of the wire telephone, contains a sensitive diaphragm which your voice strikes and sets to vibrating. These vibrations compress and release a capsule of carbon granules which agitate and set in motion an electrical current in two magnets connecting with them. The magnets convey the sound-waves in the form of electrical waves, along wires out to the tip of each wing, where the wires hang down a little way. When a message comes in it is caught by a webbing of antennae wires in our wings."