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The conquest of the air has been the dream of mankind for uncounted centuries. As far back as we have historic records we find stories of the attempts of men to fly. The earliest Greek mythology is full of aeronautical legends, and the disaster which befell Icarus and his wings of wax when exposed to the glare of the midsummer sun in Greece, is part of the schoolboy's task in Ovid. We find like traditions in the legendary lore of the Peruvians, the East Indians, the Babylonians, even the savage races of darkest Africa. In the Hebrew scriptures the chief badge of sanctity conferred on God's angels was wings, and the ability to fly. If we come down to the mythology of more recent times we find our pious ancestors in New England thoroughly convinced that the witches they flogged and hanged were perfectly able to navigate the air on a broomstick—thus antedating the Wrights' experiments with heavier-than-air machines by more than 250 years.

It is an interesting fact, stimulating to philosophical reflection, that in the last decade more has been done toward the conquest of the air, than in the twenty centuries preceding it, though during all that period men had been dreaming, planning, and experimenting upon contrivances for flight. Moreover when success came—or such measure of success as has been won—it came by the application of an entirely novel principle hardly dreamed of before the nineteenth century.

Some of the earlier efforts to master gravity and navigate the air are worthy of brief mention if only to show how persistent were the efforts from the earliest historic ages to accomplish this end. Passing over the legends of the time of mythology we find that many-sided genius, Leonardo da Vinci, early in the sixteenth century, not content with being a painter, architect, sculptor, engineer and designer of forts, offering drawings and specifications of wings which, fitted to men, he thought would enable them to fly. The sketches are still preserved in a museum at Paris. He modelled his wings on those of a bat and worked them with ropes passing over pulleys, the aviator lying prone, face downward, and kicking with both arms and legs with the vigour of a frog. There is, unhappily, no record that the proposition ever advanced beyond the literary stage—certainly none that Da Vinci himself thus risked his life. History records no one who kicked his way aloft with the Da Vinci device. But the manuscript which the projector left shows that he recognized the modern aviator's maxim, "There's safety in altitude." He says, in somewhat confused diction:

The bird should with the aid of the wind raise itself to a great height, and this will be its safety; because although the revolutions mentioned may happen there is time for it to recover its equilibrium, provided its various parts are capable of strong resistance so that they may safely withstand the fury and impetus of the descent.

Photo by Peter A. Juley.

The Fall of the Boche. From the painting by Lieutenant Farré.

The fallacy that a man could, by the rapid flapping of wings of any sort, overcome the force of gravity persisted up to a very recent day, despite the complete mathematical demonstration by von Helmholtz in 1878 that man could not possibly by his own muscular exertions raise his own weight into the air and keep it suspended. Time after time the "flapping wings" were resorted to by ambitious aviators with results akin to those attained by Darius Green. One of the earliest was a French locksmith named Besnier, who had four collapsible planes on two rods balanced across his shoulders. These he vigorously moved up and down with his hands and feet, the planes opening like covers of a book as they came down, and closing as they came up. Besnier made no attempt to raise himself from the ground, but believed that once launched in the air from an elevation he could maintain himself, and glide gradually to earth at a considerable distance. It is said that he and one or two of his students did in a way accomplish this. Others, however, experimenting with the same method came to sorry disaster. Among these was an Italian friar whom King James IV. of Scotland had made Prior of Tongland. Equipped with a pair of large feather wings operated on the Besnier principle, he launched himself from the battlements of Stirling Castle in the presence of King James and his court. But gravity was too much for his apparatus, and turning over and over in mid-air he finally landed ingloriously on a manure heap—at that period of nascent culture a very common feature of the pleasure grounds of a palace. He had a soul above his fate however, for he ascribed his fall not to vulgar mechanical causes, but wholly to the fact that he had overlooked the proper dignity of flight by pluming his wings with the feathers of common barn-yard fowl instead of with plumes plucked from the wings of eagles!

In sharp competition with the aspiring souls who sought to fly with wings—the forerunners of the airplane devotees of to-day—were those who tried to find some direct lifting device for a car which should contain the aviators. Some of their ideas were curiously logical and at the same time comic. There was, for example, a priest, Le Père Galien of Avignon. He observed that the rarified air at the summit of the Alps was vastly lighter than that in the valleys below. What then was to hinder carrying up empty sacks of cotton or oiled silk to the mountain tops, opening them to the lighter air of the upper ranges, and sealing them hermetically when filled by it. When brought down into the valleys they would have lifting power enough to carry tons up to the summits again. The good Father's education in physics was not sufficiently advanced to warn him that the effort to drag the balloons down into the valley would exact precisely the force they would exert in lifting any load out of the valley—if indeed they possessed any lifting power whatsoever, which is exceedingly doubtful.

Another project, which sounded logical enough, was based on the irrefutable truth that as air has some weight—to be exact 14.70 pounds for a column one inch square and the height of the earth's atmosphere—a vacuum must be lighter, as it contains nothing, not even air. Accordingly in the seventeenth century, one Francisco Lana, another priest, proposed to build an airship supported by four globes of copper, very thin and light, from which all the air had been pumped. The globes were to be twenty feet in diameter, and were estimated to have a lifting force of 2650 pounds. The weight of the copper shells was put at 1030 pounds, leaving a margin of possible weight for the car and its contents of 1620 pounds. It seemed at first glance a perfectly reasonable and logical plan. Unhappily one factor in the problem had been ignored. The atmospheric pressure on each of the globes would be about 1800 tons. Something more than a thin copper shell would be needed to resist this crushing force and an adequate increase in the strength of the shells would so enhance their weight as to destroy their lifting power.

Lana's Vacuum Balloon.

To tell at length the stories of attempt and failure of the earliest dabblers in aeronautics would be unprofitable and uninteresting. Not until the eighteenth century did the experimenters with lighter-than-air devices show any practical results. Not until the twentieth century did the advocates of the heavier-than-air machines show the value of their fundamental idea. The former had to discover a gaseous substance actually lighter, and much lighter, than the surrounding atmosphere before they could make headway. The latter were compelled to abandon wholly the effort to imitate the flapping of a bird's wings, and study rather the method by which the bird adjusts the surface of its wings to the wind and soars without apparent effort, before they could show the world any promising results.

Nearly every step forward in applied science is accomplished because of the observation by some thoughtful mind of some common phenomenon of nature, and the later application of those observations to some useful purpose.

It seems a far cry from an ancient Greek philosopher reposing peacefully in his bath to a modern Zeppelin, but the connection is direct. Every schoolboy knows the story of the sudden dash of Archimedes, stark and dripping from his tub, with the triumphant cry of "Eureka!"—"I have found it!" What he had found was the rule which governed the partial flotation of his body in water. Most of us observe it, but the philosophical mind alone inquired "Why?" Archimedes' answer was this rule which has become a fundamental of physics: "A body plunged into a fluid is subjected by this fluid to a pressure from below to above equal to the weight of the fluid displaced by the body." A balloon is plunged in the air—a fluid. If it is filled with air there is no upward pressure from below, but if it is filled with a gas lighter than air there is a pressure upward equal to the difference between the weight of that gas and that of an equal quantity of air. Upon that fact rests the whole theory and practice of ballooning.

The illustration of James Watt watching the steam rattle the cover of a teapot and from it getting the rudimentary idea of the steam engine is another case in point. Sometimes however the application of the hints of nature to the needs of man is rather ludicrously indirect. Charles Lamb gravely averred that because an early Chinaman discovered that the flesh of a pet pig, accidentally roasted in the destruction by fire of his owner's house, proved delicious to the palate, the Chinese for years made a practice of burning down their houses to get roast pig with "crackling." Early experimenters in aviation observed that birds flapped their wings and flew. Accordingly they believed that man to fly must have wings and flap them likewise. Not for hundreds of years did they observe that most birds flapped their wings only to get headway, or altitude, thereafter soaring to great heights and distances merely by adjusting the angle of their wings to the various currents of air they encountered.

In a similar way the earliest experimenters with balloons observed that smoke always ascended. "Let us fill a light envelope with smoke," said they, "and it will rise into the air bearing a burden with it." All of which was true enough, and some of the first balloonists cast upon their fires substances like sulphur and pitch in order to produce a thicker smoke, which they believed had greater lifting power than ordinary hot air.

In the race for actual accomplishment the balloonists, the advocates of lighter-than-air machines, took the lead at first. It is customary and reasonable to discard as fanciful the various devices and theories put forward by the experimenters in the Middle Ages and fix the beginning of practical aeronautical devices with the invention of hot-air balloons by the Montgolfiers, of Paris, in 1783.

The Montgolfier brothers, Joseph and Jacques, were paper-makers of Paris. The family had long been famous for its development of the paper trade, and the many ingenious uses to which they put its staple. Just as the tanners of the fabled town in the Middle Ages thought there was "nothing like leather" with which to build its walls and gates, thereby giving a useful phrase to literature, so the Montgolfiers thought of everything in terms of paper. Sitting by their big open fireplace one night, so runs the story, they noticed the smoke rushing up the chimney. "Why not fill a big paper bag with smoke and make it lift objects into the air?" cried one. The experiment was tried next day with a small bag and proved a complete success. A neighbouring housewife looked in, and saw the bag bumping about the ceiling, but rapidly losing its buoyancy as the smoke escaped.

Montgolfier's Experimental Balloon.

"Why not fasten a pan below the mouth of the bag," said she, "and put your fire in that? Its weight will keep the bag upright, and when it rises will carry the smoke and the pan up with it."

Acting upon the hint the brothers fixed up a small bag which sailed up into the air beyond recapture. After various experiments a bag of mixed paper and linen thirty-five feet in diameter was inflated and released. It soared to a height of six thousand feet, and drifted before the wind a mile or more before descending. The ascent took place at Avonay, the home at the time of the Montgolfiers, and as every sort of publicity was given in advance, a huge assemblage including many officials of high estate gathered to witness it. A roaring fire was built in a pit over the mouth of which eight men held the great sack, which rolled, and beat about before the wind as it filled and took the form of a huge ball. The crowd was unbelieving and cynical, inclined to scoff at the idea that mere smoke would carry so huge a construction up into the sky. But when the signal was given to cast off, the balloon rose with a swiftness and majesty that at first struck the crowd dumb, then moved it to cheers of amazement and admiration. It went up six thousand feet and the Montgolfiers were at once elevated to almost an equal height of fame. The crowd which watched the experiment was wild with enthusiasm; the Montgolfiers elated with the first considerable victory over the force of gravity. They had demonstrated a principle and made their names immortal. What remained was to develop that principle and apply it to practical ends. That development, however, proceeded for something more than a century before anything like a practical airship was constructed.

But for the moment the attack on the forces which had kept the air virgin territory to man was not allowed to lag. In Paris public subscriptions were opened to defray the cost of a new and greater balloon. By this time it was known that hydrogen gas, or "inflammable air" as it was then called, was lighter than air. But its manufacture was then expensive and public aid was needed for the new experiment which would call at the outset for a thousand pounds of iron filings and 498 pounds of sulphuric acid wherewith to manufacture the gas.

The first experiment had been made in the provinces. This one was set for Paris, and in an era when the French capital was intellectually more alert, more eager for novelty, more interested in the advancement of physical science and in new inventions than ever in its long history of hospitality to the new idea. They began to fill the bag August 23, 1783 in the Place des Victoires, but the populace so thronged that square that two days later it was moved half filled to Paris's most historic point, the Champ de Mars. The transfer was made at midnight through the narrow dark streets of mediæval Paris. Eyewitnesses have left descriptions of the scene. Torch-bearers lighted on its way the cortège the central feature of which was the great bag, half filled with gas, flabby, shapeless, monstrous, mysterious, borne along by men clutching at its formless bulk. The state had recognized the importance of the new device and cuirassiers in glittering breastplates on horseback, and halbardiers in buff leather on foot guarded it in its transit through the sleeping city. But Paris was not all asleep. An escort of the sensation-loving rabble kept pace with the guards. The cries of the quarters rose above the tramp of the armed men. Observers have recorded that the passing cab drivers were so affected by wonder that they clambered down from their boxes and with doffed hats knelt in the highway while the procession passed.

The ascension, which occurred two days later, was another moving spectacle. In the centre of the great square which has seen so many historic pageants, rose the swaying, quivering balloon, now filled to its full capacity of twenty-two thousand feet. Whether from the art instinct indigenous to the French, or some superstitious idea like that which impels the Chinese to paint eyes on their junks, the balloon was lavishly decorated in water colours, with views of rising suns, whirling planets, and other solar bodies amongst which it was expected to mingle.

Ranks of soldiers kept the populace at a distance, while within the sacred precincts strolled the King and the ladies and cavaliers of his court treading all unconsciously on the brink of that red terror soon to engulf the monarchy. The gas in the reeling bag was no more inflammable than the air of Paris in those days just before the Revolution. With a salvo of cannon the guy-ropes were released and the balloon vanished in the clouds.

Benjamin Franklin, at the moment representing in France the American colonies then struggling for liberty, witnessed this ascension! "Of what use is a new-born child?" he remarked sententiously as the balloon vanished. 'Twas a saying worthy of a cautious philosopher. Had Franklin been in Paris in 1914 he would have found the child, grown to lusty manhood, a strong factor in the city's defence. It is worth noting by the way that so alert was the American mind at that period that when the news of the Montgolfiers' achievement reached Philadelphia it found David Rittenhouse and other members of the Philosophical Society already experimenting with balloons.

Photo by Peter A. Juley.

A Rescue at Sea. From the painting by Lieutenant Farré.

A curious sequel attended the descent of the Montgolfier craft which took place in a field fifteen miles from Paris. Long before the days of newspapers, the peasants had never heard of balloons, and this mysterious object, dropping from high heaven into their peaceful carrot patch affrighted them. Some fled. Others approached timidly, armed with the normal bucolic weapons—scythes and pitchforks. Attacked with these the fainting monster, which many took for a dragon, responded with loud hisses and emitted a gas of unfamiliar but most pestiferous odour. It suggested brimstone, which to the devout in turn implied the presence of Satan. With guns, flails, and all obtainable weapons they fell upon the emissary of the Evil One, beat him to the ground, crushed out of him the vile-smelling breath of his nostrils, and finally hitched horses to him and dragged him about the fields until torn to tatters and shreds.

When the public-spirited M. Charles who had contributed largely to the cost of this experiment came in a day or two to seek his balloon he found nothing but some shreds of cloth, and some lively legends of the prowess of the peasants in demolishing the devil's own dragon.

The government, far-sightedly, recognizing that there would be more balloons and useful ones, thereupon issued this proclamation for the discouragement of such bucolic valour:

A discovery has been made which the government deems it wise to make known so that alarm may not be occasioned to the people. On calculating the different weights of inflammable and common air it has been found that a balloon filled with inflammable air will rise toward heaven until it is in equilibrium with the surrounding air; which may not happen till it has attained to a great height. Anyone who should see such a globe, resembling the moon in an eclipse, should be aware that far from being an alarming phenomenon it is only a machine made of taffetas, or light canvas covered with paper, that cannot possibly cause any harm and which will some day prove serviceable to the wants of society.

Came now the next great step in the progress of aeronautics. It had been demonstrated that balloons could lift themselves. They had even been made to lift dumb animals and restore them to earth unhurt. But if the conquest of the air was to amount to anything, men must go aloft in these new machines. Lives must be risked to demonstrate a theory, or to justify a calculation. Aeronautics is no science for laboratory or library prosecution. Its battles must be fought in the sky, and its devotees must be willing to offer their lives to the cause. In that respect the science of aviation has been different from almost any subject of inquiry that has ever engaged the restless intellect of man, unless perhaps submarine navigation, or the invention of explosives. It cannot be prosecuted except with a perfect willingness to risk life. No doubt this is one of the reasons why practical results seemed so long in the coming. Nor have men been niggardly in this enforced sacrifice. Though no records of assured accuracy are available, the names of forty-eight aeronauts who gave up their lives in the century following the Montgolfiers' invention are recorded. That record ended in 1890. How many have since perished, particularly on the battlefields of Europe where aircraft are as commonplace as cannon, it is too early yet to estimate.

Montgolfier's Passenger Balloon.

After the success of the ascension from the Champ de Mars, the demand at once arose for an ascension by a human being. It was a case of calling for volunteers. The experiments already made showed clearly enough that the balloon would rise high in air. Who would risk his life soaring one thousand feet or more above the earth, in a flimsy bag, filled with hot air, or inflammable gas, without means of directing its course or bringing it with certainty and safety back to a landing place? It was a hard question, and it is interesting to note that it was answered not by a soldier or sailor, not by an adventurer, or devil-may-care spirit, but by a grave and learned professor of physical science, Pilatre de Rozier. Presently he was joined in his enterprise by a young man of the fashionable world and sporting tastes, the Marquis d'Arlandes. Aristocratic Paris took up aviation in the last days of the eighteenth century, precisely as the American leisure class is taking it up in the first days of the twentieth.

The balloon for this adventure was bigger than its predecessors and for the first time a departure was taken from the spherical variety—the gas bag being seventy-four feet high, and forty-eight feet in diameter. Like the first Montgolfier balloons it was to be inflated with hot air, and the car was well packed with bundles of fuel with which the two aeronauts were to fill the iron brazier when its fires went down. The instinct for art and decoration, so strong in the French mind, had been given full play by the constructors of this balloon and it was painted with something of the gorgeousness of a circus poster.

A tremendous crowd packed the park near Paris whence the ascent was made. Always the spectacle of human lives in danger has a morbid attraction for curiosity seekers, and we have seen in our own days throngs attracted to aviation congresses quite as much in the expectation of witnessing some fatal disaster, as to observe the progress made in man's latest conquest over nature. But in this instance the occasion justified the widest interest. It was an historic moment—more epoch-making than those who gathered in that field in the environs of Paris could have possibly imagined. For in the clumsy, gaudy bag, rolling and tossing above a smoky fire lay the fundamentals of those great airships that, perfected by the persistence of Count Zeppelin, have crossed angry seas, breasted fierce winds, defied alike the blackest nights and the thickest fogs to rain their messages of death on the capital of a foe.

Contemporary accounts of this first ascension are but few, and those that have survived have come down to us in but fragmentary form. It was thought needful for two to make the ascent, for the car, or basket, which held the fire hung below the open mouth of the bag, and the weight of a man on one side would disturb the perfect equilibrium which it was believed would be essential to a successful flight. The Marquis d'Arlandes in a published account of the brief flight, which sounds rather as if the two explorers of an unknown element were not free from nervousness, writes:

"Our departure was at fifty-four minutes past one, and occasioned little stir among the spectators. Thinking they might be frightened and stand in need of encouragement I waved my arm."

This solicitude for the fears of the spectators, standing safely on solid earth while the first aeronauts sailed skywards, is characteristically Gallic. The Marquis continues:

M. de Rozier cried: "You are doing nothing, and we are not rising." I stirred the fire and then began to scan the river, but Pilatre again cried: "See the river. We are dropping into it!" We again urged the fire, but still clung to the river bed. Presently I heard a noise in the upper part of the balloon, which gave a shock as though it had burst. I called to my companion: "Are you dancing?" The balloon by this time had many holes burnt in it and using my sponge I cried that we must descend. My companion however explained that we were over Paris and must now cross it; therefore raising the fire once more we turned south till we passed the Luxembourg, when, extinguishing the flames, the balloon came down spent and empty.

If poor Pilatre played the part of a rather nervous man in this narrative he had the nerve still to go on with his aeronautical experiments to the point of death. In 1785 he essayed the crossing of the English Channel in a balloon of his own design, in which he sought to combine the principles of the gas and hot-air balloons. It appears to have been something like an effort to combine nitro-glycerine with an electric spark. At any rate the dense crowds that thronged the coast near Boulogne to see the start of the "Charles—Montgolfier"—as the balloon was named after the originators of the rival systems—saw it, after half an hour's drift out to sea, suddenly explode in a burst of flame. De Rozier and a friend who accompanied him were killed. A monument still recalls their fate, which however is more picturesquely recorded in the signs of sundry inns and cafés of the neighbourhood which offer refreshment in the name of Les Aviateurs Perdus.

Thereafter experimenters with balloons multiplied amazingly. The world thought the solution of the problem of flight had been found in the gas bag. Within two months a balloon capable of lifting eighteen tons and carrying seven passengers ascended three thousand feet at Lyons, and, though sustaining a huge rent in the envelope, because of the expansion of the gas at that height, returned to earth in safety. The fever ran from France to England and in 1784, only a year after the first Montgolfier experiments, Lunardi, an Italian aeronaut made an ascension from London which was viewed by King George III. and his ministers, among them William Pitt. But the early enthusiasm for ballooning quickly died down to mere curiosity. It became apparent to all that merely to rise into the air, there to be the helpless plaything of the wind, was but a useless and futile accomplishment. Pleasure seekers and mountebanks used balloons for their own purposes, but serious experimenters at once saw that if the invention of the balloon was to be of the slightest practical value some method must be devised for controlling and directing its flight. To this end some of the brightest intellects of the world directed their efforts, but it is hardly overstating the case to say that more than a century passed without any considerable progress toward the development of a dirigible balloon.

Charles's Balloon.

But even at the earlier time it was evident enough that the Quaker philosopher, from the American Colonies, not yet the United States, whose shrewd and inquiring disposition made him intellectually one of the foremost figures of his day, foresaw clearly the great possibilities of this new invention. In letters to Sir Joseph Banks, then President of the Royal Society of London, Franklin gave a lively account of the first three ascensions, together with some comments, at once suggestive and humorous, which are worth quoting:

Some think [he wrote of the balloon] Progressive Motion on the Earth may be advanc'd by it, and that a Running Footman or a Horse slung and suspended under such a Globe so as to have no more of Weight pressing the Earth with their Feet than Perhaps 8 or 10 Pounds, might with a fair Wind run in a straight Line across Countries as fast as that Wind, and over Hedges, Ditches and even Waters. It has been even fancied that in time People will keep such Globes anchored in the Air to which by Pullies they may draw up Game to be preserved in the Cool and Water to be frozen when Ice is wanted. And that to get Money it will be contriv'd, by running them up in an Elbow Chair a Mile high for a guinea, etc., etc.

With his New England lineage Franklin could hardly have failed of this comparison: "A few Months since the Idea of Witches riding through the Air upon a broomstick, and that of Philosophers upon a Bag of Smoke would have appeared equally impossible and ridiculous."

To-day when aircraft are the eyes of the armies in the greatest war of history, and when it appears that, with the return of peace, the conquest of the air for the ordinary uses of man will be swiftly completed, Franklin's good-humoured plea for the fullest experimentation is worth recalling. And the touch of piety with which he concludes his argument is a delightful example of the whimsical fashion in which he often undertook to bolster up a mundane theory with a reference to things supernatural.

© U. & U.

A French Observation Balloon on Fire.

I am sorry this Experiment is totally neglected in England, where mechanic Genius is so strong. I wish I could see the same Emulation between the two Nations as I see between the two Parties here. Your Philosophy seems to be too bashful. In this Country we are not so much afraid of being laught at. If we do a foolish thing, we are the first to laugh at it ourselves, and are almost as much pleased with a Bon Mot or a Chanson, that ridicules well the Disappointment of a Project, as we might have been with its success. It does not seem to me a good reason to decline prosecuting a new Experiment which apparently increases the power of Man over Matter, till we can see to what Use that Power may be applied. When we have learnt to manage it, we may hope some time or other to find Uses for it, as men have done for Magnetism and Electricity, of which the first Experiments were mere Matters of Amusement.

This Experience is by no means a trifling one. It may be attended with important Consequences that no one can foresee. We should not suffer Pride to prevent our progress in Science.

Beings of a Rank and Nature far superior to ours have not disdained to amuse themselves with making and launching Balloons, otherwise we should never have enjoyed the Light of those glorious objects that rule our Day & Night, nor have had the Pleasure of riding round the Sun ourselves upon the Balloon we now inhabit.

B. Franklin.

The earliest experimenters thought that oars might be employed to propel and direct a balloon. The immediate failure of all endeavours of this sort, led them, still pursuing the analogy between a balloon and a ship at sea, to try to navigate the air with sails. This again proved futile. It is impossible for a balloon, or airship to "tack" or manœuvre in any way by sail power. It is in fact a monster sail itself, needing some other power than the wind to make headway or steerage way against the wind. The sail device was tested only to be abandoned. Only when a trail rope dragging along the ground or sea is employed does the sail offer sufficient resistance to the wind to sway the balloon's course this way or that. And a trailer is impracticable when navigating great heights.

Roberts Brothers' Dirigible.

For these reasons the development of the balloon lagged, until Count Zeppelin and M. Santos-Dumont consecrated their fortunes, their inventive minds, and their amazing courage to the task of perfecting a dirigible. In a book, necessarily packed with information concerning the rapid development of aircraft which began in the last decade of the nineteenth century and was enormously stimulated during the war of all the world, the long series of early experiments with balloons must be passed over hastily. Though interesting historically these experiments were futile. Beyond having discovered what could not be done with a balloon the practitioners of that form of aeronautics were little further along in 1898 when Count Zeppelin came along with the first plan for a rigid dirigible than they were when Blanchard in 1786, seizing a favourable gale drifted across the English Channel to the French shore, together with Dr. Jefferies, an American. It was just 124 years later that Bleriot, a Frenchman, made the crossing in an airplane independently of favouring winds. It had taken a century and a quarter to attain this independence.

In a vague way the earliest balloonists recognized that power, independent of wind, was necessary to give balloons steerage way and direction. Steam was in its infancy during the early days of ballooning, but the efforts to devise some sort of an engine light enough to be carried into the air were untiring. Within a year after the experiments of the Montgolfier brothers, the suggestion was made that the explosion of small quantities of gun-cotton and the expulsion of the resulting gases might be utilized in some fashion to operate propelling machinery. Though the suggestion was not developed to any useful point it was of interest as forecasting the fundamental idea of the gas engines of to-day which have made aviation possible—that is, the creation of power by a series of explosions within the motor.

In the effort to make balloons dirigible one of the first steps was to change the form from the spherical or pear-shaped bag to a cylindrical, or cigar-shape. This device was adopted by the brothers Robert in France as early as 1784. Their balloon further had a double skin or envelope, its purpose being partly to save the gas which percolated through the inner skin, partly to maintain the rigidity of the structure. As gas escapes from an ordinary balloon it becomes flabby, and can be driven through the air only with extreme difficulty. In the balloon of the Robert brothers air could from time to time be pumped into the space between the two skins, keeping the outer envelope always fully distended and rigid. In later years this idea has been modified by incorporating in the envelope one large or a number of smaller balloons or "balloonets," into which air may be pumped as needed.

The shape too has come to approximate that of a fish rather than a bird, in the case of balloons at least. "The head of a cod and the tail of a mackerel," was the way Marey-Monge, the French aeronaut described it. Though most apparent in dirigible balloons, this will be seen to be the favourite design for airplanes if the wings be stripped off, and the body and tail alone considered. Complete, these machines are not unlike a flying fish.

In England, Sir George Cayley, as early as 1810 studied and wrote largely on the subject of dirigibles but, though the English call him the "father of British aeronautics," his work seems to have been rather theoretical than practical. He did indeed demonstrate mathematically that no lifting power existed that would support the cumbrous steam-engine of that date, and tried to solve this dilemma by devising a gas engine, and an explosive engine. With one of the latter, driven by a series of explosions of gunpowder, each in a separate cell set off by a detonator, he equipped a flying machine which attained a sufficient height to frighten Cayley's coachman, whom he had persuaded to act as pilot. The rather unwilling aviator, fearing a loftier flight, jumped out and broke his leg. Though by virtue of this martyrdom his name should surely have descended to fame with that of Cayley it has been lost, together with all record of any later performances of the machine, which unquestionably embodied some of the basic principles of our modern aircraft, though it antedated the first of these by nearly a century.