The story of the development of the heavier-than-air machine—which were called aËroplanes at first, but have been given the simpler name of airplanes—is far shorter than that of the balloons. It is really a record of achievement made since 1903 when the plane built by Professor Langley of the Smithsonian Institution came to utter disaster on the Potomac. In 1917, at the time of writing this book, there are probably thirty distinct types of airplanes being manufactured for commercial and military use, and not less than fifty thousand are being used daily over the battlefields of Europe. No invention save possibly the telephone and the automobile ever attained so prodigious a development in so brief a time. Wise observers hold that the demand for these machines is yet in its infancy, and that when the end of the war shall lead manufacturers and designers to turn their attention to the commercial value of the airplane the flying craft will be as common in the air as the automobiles at least on our country roads.

The idea of flying like a bird with wings, the idea basicly underlying the airplane theory, is old enough—almost as old as the first conception of the balloon, before hydrogen gas was discovered. In an earlier chapter some account is given of early experiments with wings. No progress was made along this line until the hallucination that man could make any headway whatsoever against gravity by flapping artificial wings was definitely abandoned. There was more promise in the experiments made by Sir George Cayley, and he was followed in the first half of the nineteenth century by half a dozen British experimenters who were convinced that a series of planes, presenting a fixed angle to the breeze and driven against it by a sufficiently powerful motor, would develop a considerable lifting power. This was demonstrated by Henson, in 1842, Stringfellow, in 1847, Wenham, who arranged his planes like slats in a Venetian blind and first applied the modern term "aeroplane" to his invention, and Sir Hiram Maxim, who built in 1890 the most complicated and impressive looking 'plane the world has yet seen. But though each of these inventors proved the theorem that a heavier-than-air machine could be made to fly, all failed to get practical results because no motor had then been invented which combined the necessary lightness with the generation of the required power.

In America we like to think of the brothers Wright as being the true inventors of the airplane. And indeed they did first bring it to the point of usefulness, and alone among the many pioneers lived to see the adoption of their device by many nations for serious practical use. But it would be unjust to claim for them entire priority in the field of the glider and the heavier-than-air machine. Professor Langley preceded them with an airplane which, dismissed with ridicule as a failure in his day, was long after his death equipped with a lighter motor and flown by Glenn Curtis, who declared that the scientist had solved the problem, had only the explosive engine been perfected in his time.

Despite, however, the early period of the successful experiments of the Wrights and Professor Langley, it would be unjust for America to arrogate to herself entire priority in airplane invention. Any story of that achievement which leaves out Lilienthal, the German, and Pilcher, the Englishman, is a record in which the truth is subordinated to national pride.

Otto Lilienthal and his brother Gustav—the two like the Wrights were always associated in their aviation work—had been studying long the problem of flight when in 1889 they jointly published their book Bird Flight as the Basis of the Flying Art. Their investigations were wholly into the problem of flight without a motor. At the outset they even harked back to the long-abandoned theory that man could raise himself by mere muscular effort, and Otto spent many hours suspended at the end of a rope flapping frantically a pair of wings before he abandoned this effort as futile. Convinced that the soaring or gliding of the birds was the feat to emulate, he made himself a pair of fixed, bat-like wings formed of a light fabric stretched over a willow frame. A tail composed of one vertical and one horizontal plane extended to the rear, and in the middle the aviator hung by his armpits, in an erect position. With this device he made some experimental glides, leaping from slight eminences. With his body, which swung at will from its cushioned supports, he could balance, and even steer the fabric which supported him, and accomplished long glides against the wind. Not infrequently, running into the teeth of the breeze down a gentle slope he would find himself gently wafted into the air and would make flights of as much as three hundred yards, steering to either side, or rising and falling at will. He was even able to make a circuitous flight and return to his starting place—a feat that was not accomplished with a motor-driven airplane until years later. Lilienthal achieved it with no mechanical aid, except the wings. He became passionately devoted to the art, made more than two thousand flights, and at the time of his death had just completed a motor-driven airplane, which he was never able to test. His earlier gliding wings he developed into a form of biplane, with which he made several successful flights, but met his death in 1896 by the collapse of this machine, of the bad condition of which he had been warned.

Lilienthal was more of a factor in the conquest of the air than his actual accomplishments would imply. His persistent experiments, his voluminous writings, and above all his friendly and intelligent interest in the work of other and younger men won him a host of disciples in other lands who took up the work that dropped from his lifeless hands.

In England Percy S. Pilcher emulated the Lilienthal glides, and was at work on a motor-propelled machine when he was killed by the breakage of a seemingly unimportant part of his machine. He was on the edge of the greater success, not to that moment attained by anyone, of building a true airplane propelled by motor. Many historians think that to Lilienthal and Pilcher is justly due the title "the first flying men." But Le Bris, a French sailor, utterly without scientific or technical equipment, as far back as 1854 had accomplished a wonderful feat in that line. While on a cruise he had watched an albatross that followed his ship day after day apparently without rest and equally without fatigue. His imagination was fired by the spectacle and probably having never heard of the punishment that befell the Ancient Mariner, he shot the albatross. "I took the wing," he wrote later, "and exposed it to the breeze, and lo, in spite of me, it drew forward into the wind; notwithstanding my resistance it tended to rise. Thus I had discovered the secret of the bird. I comprehend the whole mystery of flight."

A trifle too sanguine was sailor Le Bris, but he had just the qualities of imagination and confidence essential to one who sets forth to conquer the air. Had he possessed the accurate mind, the patience, and the pertinacity of the Wrights he might have beaten them by half a century. As it was he accomplished a remarkable feat, though it ended in somewhat laughable failure. He built an artificial bird, on the general plan of his albatross. The wings were not to flap, but their angles to the wind were controlled by a system of levers controlled by Le Bris, who stood up in the basket in the centre. To rise he required something like the flying start which the airplanes of to-day get on their bicycle wheels before leaving the ground. As Le Bris had no motor this method of propulsion was denied him, so he loaded the apparatus in a cart, and fastened it to the rail by a rope knotted in a slip knot which a jerk from him would release. As they started men walked beside the cart holding the wings, which extended for twenty-five feet on either side. As the horses speeded up these assistants released their hold. Feeling the car try to rise under his feet Le Bris cast off the rope, tilted the front end of the machine, and to his joy began to rise steadily into the air. The spectators below cheered madly, but a note of alarm mingled with their cheers, and the untried aviator noticed a strange and inexplicable jerking of his machine. Peering down he discovered, to his amaze, a man kicking and crying aloud in deadly fear. It was evident that the rope he had detached from the cart had caught up the driver, who had thus become, to his intense dismay, a partner in the inventor's triumph. Indeed it is most possible that he contributed to that triumph for the ease and steadiness with which the machine rose to a height estimated at three hundred feet suggests that he may have furnished needed ballast—acted in fact as the tail to the kite. Humanity naturally impelled Le Bris to descend at once, which he did skilfully without injuring his involuntary passenger, and only slightly breaking one of the wings.

Had Le Bris won this success twenty years later his fame and fortune would have been secure. But in 1854 the time was not ripe for aeronautics. Le Bris was poor. The public responded but grudgingly to his appeals for aid. His next experiment was less successful—perhaps for lack of the carter—and he ultimately disappeared from aviation to become an excellent soldier of France.

Perhaps had they not met with early and violent deaths, the Lilienthals and Pilcher might have carried their experiments in the art of gliding into the broader domain of power flight. This however was left to the two Americans, Orville and Wilbur Wright, who have done more to advance the art of navigating the air than all the other experimenters whose names we have used. The story of the Wright brothers is one of boyhood interest gradually developed into the passion of a lifetime. It parallels to some degree the story of Santos-Dumont who insisting as a child that "man flies" finally made it a fact. The interest of the Wrights was first stimulated when, in 1878, their father brought home a small toy, called a "helicopter," which when tossed in the air rose up instead of falling. Every child had them at that time, but curiously this one was like the seed which fell upon fertile soil. The boys went mad, as boys will, on the subject of flying. But unlike most boys they nurtured and cultivated the passion and it stayed with them to manhood. From helicopters they passed to kites, and from kites to gliders. By calling they were makers and repairers of bicycles, but their spare time was for years devoted to solving the problem of flight. In time it became their sole occupation and by it they won a fortune and world-wide fame. Their story forms a remarkable testimony to the part of imagination, pertinacity, and courage in winning success. After years of tests with models, and with kites controlled from the ground, the brothers had worked out a type of glider which they believed, in a wind of from eighteen to twenty miles an hour, would lift and carry a man. But they had to find a testing ground. The fields near their home in Ohio were too level, and their firm unyielding surface was not attractive as a cushion on which to light in the event of disaster. Moreover the people round about were getting inquisitive about these grown men "fooling around" with kites and flying toys. To the last the Wrights were noted for their dislike of publicity, and it is entirely probable that the sneering criticisms of their "level headed" and "practical" neighbours had a good deal to do with rooting them in this distaste.

Low steep hills down the sides of which they could run and at the proper moment throw themselves upon their glider; a sandy soil which would at least lessen the shock of a tumble; and a vicinage in which winds of eighteen miles an hour or more is the normal atmospheric state were the conditions they sought. These they found at a little hamlet called Kitty-Hawk on the coast of North Carolina. There for uncounted centuries the tossing Atlantic had been throwing up its snowy sand upon the shore, and the steady wind had caught it up, piled it in windrows, rolled it up into towering hills, or carried it over into the dunes which extended far inland. It was a lonely spot, and there secure from observation the Wrights pitched their camp. For them it was a midsummer's holiday. Not at first did they decide to make aviation not a sport but a profession. To their camp came visitors interested in the same study, among them Chanute, a well-known experimenter, and some of his associates. They had thought to give hours at a time to actual flight. When they closed their first season, they found that all their time spent in actual flight footed up less than an hour. Lilienthal, despite all he accomplished, estimated that he, up to a short time before his death, spent only about five hours actually in the air. In that early day of experimentation a glide covering one hundred feet, and consuming eight or ten seconds, was counted a triumph.

But the season was by no means wasted. Indeed such was the estimate that the Wrights put upon it that they folded their tents determined that when they returned the year following it would be as professionals, not amateurs. They were confident of their ability to build machines that would fly, though up to that time they had never mounted a motor on their aircraft.

In the clear hot air of a North Carolina midsummer the Wrights used to lie on their backs studying through glasses the methods of flight of the great buzzards—filthy scavenger birds which none the less soaring high aloft against a blue sky are pictures of dignity and grace.

Bald eagles, ospreys, hawks, and buzzards give us daily exhibitions of their powers [wrote Wilbur Wright]. The buzzards were the most numerous, and were the most persistent soarers. They apparently never flapped except when it was absolutely necessary, while the eagles and hawks usually soared only when they were at leisure. Two methods of soaring were employed. When the weather was cold and damp and the wind strong the buzzards would be seen soaring back and forth along the hills or at the edge of a clump of trees. They were evidently taking advantage of the current of air flowing upward over these obstructions. On such days they were often utterly unable to soar, except in these special places. But on warm clear days when the wind was light they would be seen high in the air soaring in great circles. Usually, however, it seemed to be necessary to reach a height of several hundred feet by flapping before this style of soaring became possible. Frequently a great number of them would begin circling in one spot, rising together higher and higher till finally they would disperse, each gliding off in whatever direction it wished to go. At such times other buzzards only a short distance away found it necessary to flap frequently in order to maintain themselves. But when they reached a point beneath the circling flock they began to rise on motionless wings. This seemed to indicate that rising columns of air do not exist everywhere, but that the birds must find them. They evidently watch each other and when one finds a rising current the others quickly make their way to it. One day when scarce a breath of wind was stirring on the ground we noticed two bald eagles sailing in circling sweeps at a height of probably five hundred feet. After a time our attention was attracted to the flashing of some object considerably lower down. Examination with a field-glass proved it to be a feather which one of the birds had evidently cast. As it seemed apparent that it would come to earth only a short distance away, some of our party started to get it. But in a little while it was noted that the feather was no longer falling, but on the contrary was rising rapidly. It finally went out of sight upward. It apparently was drawn into the same current in which the eagles were soaring and was carried up like the birds.

It was by such painstaking methods as these, coupled with the mathematical reduction of the fruits of such observations to terms of angles and supporting planes, that the Wrights gradually perfected their machine. The first airplane to which they fitted a motor and which actually flew has been widely exhibited in the United States, and is to find final repose in some public museum. Study it as you will you can find little resemblance in those rectangular rigid planes to the wings of a bird. But it was built according to deductions drawn from natural flight.

The method of progress in these preliminary experiments was, by repeated tests, to determine what form of airplane, and of what proportions, would best support a man. It was evident that for free and continuous flight it must be able to carry not only the pilot, but an engine and a store of fuel as well. Having, as they thought, determined these conditions the Wrights essayed their first flight at their home near Dayton, Ohio. It was a cold December day in 1903. The first flight, with motor and all, lasted twelve seconds; the fourth fifty-nine seconds. The handful of people who came out to witness the marvel went home jeering. In the spring of the next year a new flight was announced near Dayton. The newspapers had been asked to send reporters. A crowd of perhaps fifty persons had gathered. Again fate was hostile. The engine worked badly and the airplane refused to rise. The crowd dispersed and the newspapermen, returning the next day, met only with another disappointment.

These repeated failures in public exhibitions resulted in creating general indifference to the real progress that the Wrights were making in solving the flight problem. While the gliding experiments at Kitty-Hawk were furnishing the data for the plans on which the tens of thousands of airplanes used in the European war were afterwards built, no American newspaper was sufficiently interested to send representatives to the spot. The people of the United States were supremely indifferent. Perhaps this was due to the fact that superficially regarded the machine the Wrights were trying to perfect gave promise of usefulness only in war or in sport. We are not either a warlike or a sporting people. Ready enough to adopt a new device which seems adapted for utilitarian purposes, as is shown by the rapid multiplication of automobiles, we leave sport to our professional ball players, and our military equipment to luck.

So after continued experimental flights in the open fields near Dayton had convinced them that the practical weaknesses in their machine had been eliminated, the Wrights packed up their flyer and went to France. Before so doing they tried to get encouragement from the United States Government, but failed. Neither the government nor any rich American was willing to share the cost of further experiments. All that had been done was at their own cost, both in time and money. In France, whither they went in 1908, they had no coldness to complain of. It was then the golden day of aviation in the land which always afforded to the Knights of the Air their warmest welcome and their most liberal support. Two years had elapsed since Santos-Dumont, turning from dirigibles to 'planes, had made a flight of 238 yards. This the Wrights had at the time excelled at home but without attracting attention. France on the contrary went mad with enthusiasm, and claimed for the Brazilian the honour of first demonstrating the possibility of flight in a heavier-than-air machine. England, like the United States, was cold, clinging to the balloon long after all other nations had abandoned it. But France welcomed the Wrights with enthusiasm. They found rivals a-plenty in their field of effort. Santos-Dumont, Bleriot, Farman, Latham were all flying with airplanes, but with models radically different from that of the American brothers. Nevertheless the latter made an instant success.

From the moment they found that they had hit upon the secret of raising, supporting, and propelling an airplane, the Wrights made of their profession a matter of cold business. In many ways this was the best contribution they could possibly have made to the science of aviation, though their keen eye to the main chance did bring down on them a certain amount of ridicule. Europe laughed long at the sang-froid with which Wilbur Wright, having won the Michelin prize of eight hundred pounds, gave no heed to the applause which the assembled throng gave him as the money was transferred to him with a neat presentation speech. Without a word he divided the notes into two packets, handed one to his brother Orville, and thrust the other into his own pocket. For the glory which attended his achievement he cared nothing. It was all in the day's work. Later in the course of trials of a machine for the United States Government at Fort Myer, just across the Potomac from Washington, the Wrights seriously offended a certain sort of public sentiment in a way which undoubtedly set back the encouragement of aviation by the United States Government very seriously.

In 1909, they had received a contract from the government for a machine for the use of the Signal Service. The price was fixed at $25,000, but a bonus of $2500 was to be paid for every mile above forty miles an hour made by the machine on its trial trip. That bonus looked big to the Wrights, but it cost the cause of aviation many times its face value in the congressional disfavour it caused. Aviation was then in its infancy in the United States. Every man in Congress wanted to see the flights. But Fort Myer, whose parade was to be the testing ground, was fully fourteen miles from the Capitol, and reached only most inconveniently from Washington by trolley, or most expensively by carriage or automobile. Day after day members of the House and Senate made the long journey across the Potomac. Time and again they journeyed back without even a sight of the flyer in the hangar. One after another little flaws discovered in the machine led the aviators to postpone their flight. Investigating statesmen who thought that their position justified them in seeking special privileges were brusquely turned away by the military guard. The dusk of many a summer's night saw thousands of disappointed sightseers tramping the long road back to Washington. The climax came when on a clear but breezy day Wilbur Wright announced that the machine was in perfect condition and could meet its tests readily, but that in order to win a bigger bonus, he would postpone the flight for a day with less wind. All over Washington the threat was heard that night that Congress would vote no more money for aviation, and whether or not the incident was the cause, the sequence was that the American Congress was, until the menace of war with Germany in 1916, the most niggardly of all legislative bodies in its treatment of the flying corps. When the Wrights did finally fly they made a triumphant flight before twelve thousand spectators. The test involved crossing the Potomac, going down its north side to Alexandria, and then back to Fort Myer. Ringing cheers and the crashing strains of the military band greeted the return of the aviator, but oblivious to the enthusiasm Wilbur Wright stood beside his machine with pencil and pad computing his bonus. It figured up to five thousand dollars, and the reporters chronicled that the Wrights knew well the difference between solid coin and the bubble of reputation.

But this seemingly cold indifference to fame and single-minded concentration on the business of flying on the part of the Wrights was in fact of the utmost value to aviation as an art and a science. They were pioneers and successful ones. Their example was heeded by others in the business. In every way they sought to discourage that wild reaching after public favour and notoriety that led aviators to attempt reckless feats, and often sacrifice their lives in a foolish effort to astonish an audience. No one ever heard of either of the Wright brothers "looping-the-loop," doing a "demon glide," or in any other fashion reducing the profession of aviation to the level of a circus. In a time when brave and skilful aviators, with a mistaken idea of the ethics of their calling, were appealing to sensation lovers by the practice of dare-devil feats, the Wrights with admirable common sense and dignity stood sturdily against any such degradation of the aviator's art. In this position they were joined by Glenn Curtis, and the influence of the three was beginning to be shown in the reduced number of lives sacrificed in these follies when the Great War broke upon the world and gave to aviation its greatest opportunity. The world will hope nevertheless that after that war shall end the effort to adapt the airplane to the ends of peace will be no less earnest and persistent than have been the methods by which it has been made a most serviceable auxiliary of war.

In July, 1915, Collier's Weekly published an interview with Orville Wright in which that man, ordinarily of few words, set up some interesting theories upon the future of airplanes.

Mr. Wright's statement of the brevity of the time spent in actual flying in order to learn the art will astonish many people. Few novices would be so rash as to undertake to steer an automobile alone after only four hours' practice, and despite the fact that the aviator always has plenty of space to himself the airplane can hardly yet be regarded as simple a machine to handle as the automobile. Nevertheless the ease with which the method of its actual manipulation is acquired is surprising. More work is done in the classroom and on the ground to make the fighting pilot than in the air. As we have traced the development of both dirigible and airplane from the first nascent germ of their creation to the point at which they were sufficiently developed to play a large part in the greatest of all wars, let us now consider how hosts of young men, boys in truth, were trained to fly like eagles and to give battle in mid-air to foes no less well trained and desperate than they.