Chapter I: The Conquest of the Air (1)

We know next to nothing of man's greatest achievements. His written history is the history of yesterday, and leaves him very much the same being as it finds him, with the same habits, the same prejudices, and only slightly enhanced powers. The greatest and most significant advances were prehistoric. What invention, of which any record remains, can compare in importance with the invention of speech; and what day in the world's history is more worthy of celebration than that day, the birthday of thought and truth, when a sound, uttered by the breath, from being the expression of a feeling became the mark of a thing? The man who first embarked on the sea has been praised for the triple armour of his courage; but he must be content with praise; his biography will never be written. The North American Indians are reckoned a primitive people, but when first they come under the notice of history they bring with them one of the most perfect of human inventions--the birch-bark canoe. What centuries of dreams and struggles and rash adventures went to the inventing and perfecting of that frail boat? What forgotten names deserve honour for the invention of the paddle and the sail? The whole story is beyond recovery in the rapidly closing backward perspective of time. Man's eyes are set in his head so that he may go forward, and while he is healthy and alert he does not trouble to look behind him. If the beginnings of European civilization are rightly traced to certain tribes of amphibious dwellers on the coast of the Mediterranean, who reared the piles of their houses in the water, and so escaped the greater perils of the land, then some sort of rudimentary navigation was the first condition of human progress, and sea-power, which defies the devastators of continents, had earlier prophets than Admiral Mahan. But the memory of these thousands of years has passed like a watch in the night.

The conquest of the sea can never be recorded in history; even the conquest of the air, which was achieved within the lifetime of all but the very youngest of those who are now alive, admits of no sure or perfect record. The men who bore a part in it, and still survive, are preoccupied with the future, and are most of them impatient of their own past. Where knowledge begins, there begin also conflicting testimonies and competing claims. It is no part of the business of this history of the war in the air to compare these testimonies or to resolve these claims. To narrate how man learned to fly would demand a whole treatise, and the part of the history which ends in December 1903 is the most difficult and uncertain part of all. Yet the broad outlines of the process can be sketched and determined. It is a long story of legends and dreams, theories and fancies, all suddenly transformed into facts; a tale of the hopes of madmen suddenly recognized as reasonable ambitions. When in the light of the present we look back on the past our eyes are opened, and we see many things that were invisible to contemporaries. We are able, for the first time, to pay homage to the pioneers, who saw the promised kingdom, but did not enter it. No place has hitherto been found for their names in serious history. _The Dictionary of National Biography_, with its supplement, includes the lives of all the famous men of this nation who died before King George the Fifth was king. Yet it contains no mention of Sir George Cayley, the Father of British Aeronautics; nor of John Stringfellow, who, in 1848, constructed the first engine-driven aeroplane that ever flew through the air; nor of Francis Herbert Wenham, whose classic treatise on Aerial Locomotion, read at the first meeting of the Aeronautical Society, in 1866, expounds almost every principle on which modern aviation is founded; nor of James Glaisher, who, in 1862; made the highest recorded balloon ascent; nor of Percy Sinclair Pilcher, who lost his life in experimenting with one of his own gliders in 1899. These men attracted little enough notice in their own day, and were regarded as amiable eccentrics; but they all thought long and hard on aerial navigation, and step by step, at their own costs, they brought it nearer to accomplishment.

Now that the thing has been done, it seems strange that it was not done earlier. At no time was it possible for man to forget his disabilities; the birds were always above him, in easy possession. If he attributed their special powers wholly to the lightness of their structure and the strength of their muscles, the variety of flying creatures might have taught him better. The fact is that there is no unique design for flight; given the power and its right use, almost anything can fly. If the sea-gull can fly, so can the duck, with a much heavier body and a much less proportion of wing. The moth can fly; but so can the beetle. The flying-fish can fly, or rather, can leap into the air and glide for a distance of many yards. With the requisite engine-power a portmanteau or a tea-tray could support itself in the air. The muscular power of man, it is now generally accepted, is not sufficient to support his weight in level flight on still air, but if the principles of flight had been understood, there was no need to wait for the invention of the powerful internal-combustion engine; a steam-engine in a well-designed aeroplane might have performed very useful flights. It was knowledge that lingered. Newton, when he saw an apple fall in his garden at Woolsthorpe, 'began to think of gravity extending to the orb of the moon'. If he had been in the habit of skimming flat stones on calm water, he might have bent his mind to the problem of flight, and might even have anticipated some of the discoveries in aerodynamics which were reserved for the last century--in particular, the relations of speed and angle of incidence to the reactions of air resistance on a moving plane. The fact which is the basis of all aeroplane flight is that a perfectly horizontal plane, free to fall through the air, has its time of falling much retarded if it is in rapid horizontal motion. This is what makes gliding possible. Now let the plane which is being propelled in a horizontal direction be slightly tilted up, so that its front, or leading edge, is higher than its back, or trailing edge. The reaction of the air can then be resolved into two components, technically called 'lift' and 'drag'; lift, which tends to raise the plane, and drag, which retards it in its forward motion. When the angle of incidence of the plane is small, that is, when it is only slightly tilted from its direction of motion, the greater part of the air reaction is converted into lift. This is what makes flying possible. A moderate speed through the air will enable the plane to lift much more than its own weight.

This is not a technical treatise, but some further facts of signal importance in the theory and practice of flight are better explained at once, in so far as the beautiful exactitude of mathematical demonstration can be expressed in the crudities of popular speech. The lift produced by the reaction of the air acts on the whole plane, but not equally on all parts of it. At a flying angle, that is, when the angle of incidence of the plane is small, the upward force is greatest on those parts of the plane which are immediately behind the leading edge. The wings of any soaring bird are long and narrow, and thus are perfectly designed for their work. A square-winged bird would be a poor soarer; a bird the breadth of whose wings should be greater than their length could hardly fly at all. The wings of a flying machine are called planes, or aerofoils; the length of the wing is called the span of the plane; the breadth of the wing is called the chord of the plane. The proportion of the span to the chord, that is, the proportion of the length of the wing to its breadth, is called the 'aspect ratio' of the plane; and a plane, or wing, that is long and narrow is said to have a high aspect ratio. A higher aspect ratio than is found in any bird or any flying machine would theoretically improve its powers of flight, but the practicable span of the plane, or length of the wing, is limited by the need for rigidity and strength. The albatross, nevertheless, the king of soaring birds, has enormously long and narrow wings; and the planes of some flying machines have an aspect ratio almost as high as the slats of a Venetian blind.

The wings of a flying machine, it has been said, are called planes, but they are not true planes. Like the wings of a bird, they are 'cambered', that is to say, they curve upward from the leading edge and downward again to the trailing edge. Some of the most valuable work contributed by the laboratory to the science of flight has had for its object the determination of the best form of camber, or curve of the plane. In the result, that form of camber has been found to be best which attains its maximum depth a little way only behind the leading edge, and gradually becomes shallower towards the trailing edge. Such a form of curve produces a comparatively smooth and untroubled partial vacuum above the plane, just behind its leading edge, and this vacuum is the factor of chief importance in the lift of the plane.

The above is a brief and rough statement of some principles of aviation which have been ascertained by long experiment and the labour of many minds. It is by experiment that flight has been achieved. The Newton who shall reduce all the observed phenomena to a few broad and simple laws is yet to come. A bird is simpler than an aeroplane in that its wings both support it and drive it forward, whereas all aerial machines, both those that are heavier than air and those that are lighter than air, are at present driven forward by the thrust of an airscrew, revolving at the rate of some twenty to thirty times a second.

There are only two kinds of flying machine, the lighter than air and the heavier than air, of which two kinds the simplest types are the soap-bubble and the arrow. These two kinds have often been in competition with each other; and their rivalry, which has sometimes delayed progress, still continues. The chief practical objection to machines lighter than air is that they are buoyed up by vulnerable receptacles containing hydrogen or some other highly inflammable gas. As soon as helium, which is a light non-inflammable gas, shall be produced in quantity at a reasonable expense, this objection will be lessened. The advantage of the lighter-than-air, or floating, machine over the heavier-than-air, or soaring, machine is that it can remain stationary in the air without loss of height, and that its great size and lifting power enable it to supply comfortable quarters for its staff, who not only travel in it, but, if need be, can inhabit it for days. The airship has a promising future, but it can never wholly supersede the soaring machine, which is heavier than air, and flies as birds fly.

A fascinating story, part legend, part fiction, might be told of the earliest reputed inventors. The fable of Daedalus perhaps grew up round the memory of a man of mechanical genius, for Daedalus was the author of many inventions before he flew from Crete to Italy. Aulus Gellius, in his entertaining book of anecdotes called the _Attic Nights_, tells how the philosopher Archytas of Tarentum invented a mechanical pigeon, which was filled with some kind of light air, and flew. The two schools of aeronautics were here reconciled. Other mechanists were Roger Bacon, who is reported to have designed a flying chariot; and Regiomontanus, astronomer and mathematician, who made a mechanical eagle which flew to meet the Emperor Charles the Fifth, on his solemn entry into the city of Nuremberg. It is not necessary to inquire whether these stories are true or false; what is certain is that the inventors did not leave their inventions as a legacy to their fellows. For a like reason Leonardo da Vinci, who busied himself with a mechanism which should enable man to operate wings with his legs, and who left a short treatise on the art of flight, has no place in the history. His mechanism is merely a drawing; his treatise remained in manuscript. The adventurers who risked their lives on wings of their own making are truer ancestors of the flying man. In 1507 John Damian, who was held in esteem as an alchemist and physician at the court of King James IV of Scotland, 'took in hand to fly with wings, and to that effect he caused make a pair of wings of feathers, which being fastened upon him, he flew off the castle wall of Stirling, but shortly he fell to the ground and brake his thigh-bone'.[1] The poet Dunbar attacked him in a satirical poem, and the reputation of a charlatan has stuck to him, but he deserves credit for his courageous attempt. So does the Marquis de Bacqueville, who, in 1742, attached to his arms and legs planes of his own design, and launched himself from an upper story of his house in Paris, in the attempt to fly across the river Seine to the Tuileries, about two hundred yards away. He glided some distance, and then fell on a washerwoman's barge in the stream, breaking his leg in the fall. These and other disastrous attempts might be defended in the words of Wilbur Wright, written in 1901, while he was experimenting with his own gliders. 'There are two ways', he says, 'of learning how to ride a fractious horse: one is to get on him and learn by actual practice how each motion and trick may be best met; the other is to sit on a fence and watch the beast awhile, and then retire to the house and at leisure figure out the best way of overcoming his jumps and kicks. The latter system is the safest; but the former, on the whole, turns out the larger proportion of good riders. It is very much the same in learning to ride a flying machine; if you are looking for perfect safety you will do well to sit on a fence and watch the birds; but if you really wish to learn you must mount a machine and become acquainted with its tricks by actual trial.'[2] This pronouncement, by the highest authority, may serve as an apology for some of those whose attempts were reckoned madness or quackery, and whose misfortunes, during many long centuries, are the only material available for the history of human flight.

[Footnote 1: From the _History of Scotland_, by John Lesley, Bishop
of Ross, written about 1570.]

[Footnote 2: _Journal of the Western Society of Engineers_, vol. vi,
No. 6, December 1901.]

Two periods of modern European history are notable for a quickening of human interest in the problem of aerial navigation. They are the age of Louis XIV of France, and the age of the French Revolution. Both were times of great progress in science, and of illimitable hopes; but the earlier period, which in England witnessed the foundation of the Royal Society, was notable chiefly for advance in the physical and mathematical sciences; while the later period was more addicted to chemistry, and was the age of Lavoisier, Priestley, Cavendish, and Black. The former age, though it attained to nothing practical, made some progress in the theory of flight; the latter age invented the balloon.

The Royal Society took its origin in the meetings in London, during the troublous times of the Civil War, of 'divers worthy persons inquisitive into natural philosophy'. One of these worthy persons was John Wilkins, mathematician, philosopher, and divine, who, being parliamentarian in his sympathies, was, on the expulsion of the Royalists from Oxford, made Warden of Wadham College in that University. At Wadham, in the Warden's lodgings, the 'Experimental philosophical Club', as Aubrey calls it, renewed its meetings. Sprat, the early historian of the Royal Society, explains that religion and politics were forbidden topics. 'To have been always tossing about some theological question would have been to make that their private diversion of which they had had more than enough in public; to have been musing on the Civil Wars would have made them melancholy; therefore Nature alone could entertain them.' After the Restoration a meeting was held at Gresham College in London, and a committee was appointed, with Wilkins as chairman, to draw up a scheme for the Royal Society. The King approved of the scheme submitted to him, and the society received its charter in 1662.

Wilkins was a famous man in his day; he married a sister of Oliver Cromwell, and in his later years was Bishop of Chester. But his great work was the founding of the Royal Society; and his philosophical (or, as they would now be called, scientific) writings, which belong to his earlier years in London, show very clearly with what high expectations the society started on its labours. The first of these writings, published in 1638, is a discourse to prove that there may be another habitable World in the Moon. The second considers the possibility of a passage thither. The third maintains that it is probable that our Earth is one of the planets. The fourth, which is entitled _Mercury; or, the Secret Messenger_, discusses how thoughts may be communicated from a distance. The fifth and last, published in 1648, is called _Mathematical Magic_, and is divided into two books, under the titles _Archimedes; or, Mechanical Powers_, and _Daedalus; or, Mechanical Motions_. In this latter book Wilkins treats of mills, clocks, and the contrivance of motion by rarefied air; of the construction of an ark for submarine navigation, and of its uses in war; of a sailing chariot, to be driven on the land as ships are on the sea; of the possibility of perpetual motion; and, in chapters vii and viii, of the art of flying. There are four ways, according to Wilkins, whereby flying in the air may be attempted. The first is by spirits or angels; but this branch of the subject does not belong to natural philosophy. The next is by the help of fowls, which the learned Francis Bacon thought deserving of further experiment. Two ways remain of flying by our own strength; we may use wings fastened immediately to the body, or we may devise a flying chariot. If we are to use wings, he says, we must be brought up in the constant practice of them from youth, first 'running on the ground, as an ostrich or tame goose will do ... and so by degrees learn to rise higher.... I have heard it from credible testimony, that one of our own nation hath proceeded so far in this experiment, that he was able by the help of wings, in such a running pace, to step constantly ten yards at a time.' The arms of a man extended are weak, and easily wearied, so he thinks it would be worth the inquiry whether the wings might not be worked by the legs being thrust out and drawn in again one after the other, so as each leg should move both wings. But the best way of flying would be by a flying chariot, big enough to carry several persons, who might take turns to work it. Wilkins is quite honest in recognizing the difficulties of this scheme. He deals fully with the chief of them--whether so large and heavy a machine can be supported by so thin and light a body as the air; and whether the strength of the persons in it can be sufficient for the motion of it. In his attempt to show that these objections are not insuperable, he makes some true remarks. He had watched soaring birds, and had seen how they could swim up and down in the air without any sensible motion of the wings. When the right proportions of the machine are found out, and men by long practice have attained to skill and experience, we may perhaps, he thinks, be able to imitate the birds. If, after all, it be found that some greater motive power is required, we must not despair of the invention of such a power. The main difficulty will be not so much in maintaining the machine in flight as in raising it from the ground. 'When once it is aloft in the air, the motion of it will be easy, as it is in the flight of all kind of birds, which being at any great distance from the earth, are able to continue their motion for a long time and way, with little labour and weariness.' The right proportion of the wings, both for length and breadth; the special contrivances necessary for ascent, descent, or a turning motion--these and many more such questions can only be resolved, he maintains, by particular experiments. The sails of ships have been perfected by degrees, and the attempt to fly must meet with many difficulties and inconveniences for which only long experience and frequent trial can suggest a remedy.

So far Wilkins went; and he went no farther. His speculations, however, made a deep impression on his own age, gave a bias to the researches of his fellows, and, incidentally, aroused a storm of ridicule. When Joseph Glanvill, in his vigorous little treatise called _Scepsis Scientifica_ (1665), wrote a forecast of the possible achievements of the Royal Society, he borrowed his hopes from Wilkins. 'Should these heroes go on', he says, 'as they have happily begun, they will fill the world with wonders, and posterity will find many things that are now but rumours, verified into practical realities. It may be, some ages hence, a voyage to the southern unknown tracts, yea, possibly the Moon, will not be more strange than one to America. To them that come after us it may be as ordinary to buy a pair of wings to fly into remotest regions, as now a pair of boots to ride a journey. And to confer at the distance of the Indies, by sympathetic conveyances, may be as usual to future times, as to us in a literary correspondence. The restoration of grey hairs to juvenility, and renewing the exhausted marrow, may at length be effected without a miracle; and the turning the now comparative desert world into a paradise, may not improbably be expected from late agriculture.' Again, when Sir William Temple, some thirty years later, cast contempt upon the Moderns in his _Essay of Ancient and Modern Learning_, it was the speculations of Wilkins that provoked his keenest satire. 'I have indeed heard of wondrous Pretensions and Visions of Men, possess'd with Notions of the strange Advancement of Learning and Sciences, on foot in this Age, and the Progress they are like to make in the next; as, the Universal Medicine, which will certainly cure all that have it; the Philosopher's Stone, which will be found out by Men that care not for Riches: the transfusion of young Blood into old Men's Veins, which will make them as gamesome as the Lambs, from which 'tis to be derived; an Universal Language, which may serve all Men's Turn, when they have forgot their own: the Knowledge of one another's Thoughts, without the grievous Trouble of Speaking: the Art of Flying, till a Man happens to fall down and break his Neck: Double-bottom'd Ships, whereof none can ever be cast away, besides the first that was made: the admirable Virtues of that noble and necessary Juice called Spittle, which will come to be sold, and very cheap, in the Apothecaries' Shops: Discoveries of new Worlds in the Planets, and Voyages between this and that in the Moon, to be made as frequently as between York and London: which such poor Mortals as I am think as wild as those of Ariosto, but without half so much Wit, or so much Instruction; for there, these modern Sages may know where they may hope in Time to find their lost Senses, preserved in Vials, with those of Orlando.'

Both Sir William Temple and Joseph Glanvill were men of acute intelligence and complete sanity; the one an aged statesman deeply versed in the deceits and follies of men; the other a young cleric, educated in the Oxford of the Commonwealth, and stirred to enthusiasm by what he had there heard of the progress of natural philosophy. In this perennial debate the man of the world commonly triumphs; he plays for the stakes that are on the table, and does not put faith in deferred gains. For something like two hundred years Sir William Temple's triumph was almost complete. Now things have changed, and Glanvill's rhapsody comes nearer to the truth. Wireless telegraphy, radium, the discoveries of bacteriology, and not least the conquest of the air, have taken the edge off the sallies of the wit, and have verified the dreams of the prophet.

What most delayed the science and art of flight, which made no progress during the whole of the eighteenth century, was an imperfect understanding of the flight of birds. The right way to achieve flight, as events were to prove, was by the study and practice of gliding. But birds were believed to support, as well as to raise, themselves in the air chiefly by what in the jargon of science is called orthogonal flight, that is, by direct downward flapping of the wings. This view received authoritative support from a famous treatise written in the seventeenth century by Giovanni Alfonso Borelli, an Italian professor of mathematical and natural philosophy. Borelli, who held professorships at the Universities of Florence and Pisa, and corresponded with many members of the Royal Society, was an older man than Wilkins, but his book on the movements of animals (_De Motu Animalium_), which included a section on the flight of birds (_De Volatu_), was not published till 1680, when both he and Wilkins were dead. It was long held in high esteem for its anatomical exposition of the action of flying, and some of its main contentions cast a damp upon the hopes of man. The bones of a bird, says Borelli, are thin tubes of exceeding hardness, much lighter, and at the same time stronger, than the bones of a man. The pectoral muscles, which move the wings, are massive and strong--more than four times stronger, in proportion to the weight they have to move, than the legs of a man. And he states his conclusion roundly--it is impossible that man should ever achieve artificial flight by his own strength. This view, dogmatically stated by one who was a good mathematician and a good anatomist, became the orthodox view, and had an enduring influence. All imitation of the birds by man, and further, all schemes of navigating the air in a machine dynamically supported, seemed, by Borelli's argument, to have been thrust back into the limbo of vanities.

There remained only the hope that some means might be found of buoying man up in the air, thereby leaving him free to apply his muscular and mechanical powers to the business of driving himself forward. Another celebrated treatise of the seventeenth century pointed the way to such a means. Francesco Lana, a member of the Society of Jesus in Rome, spent the greater part of his life in scientific research. He planned a large encyclopaedia, embodying all existing science, in so far as it was based on experiment and proof. Of this work only two volumes appeared during his lifetime; he died at Brescia in the year 1687. But long before he died, he had produced, in 1670, a preliminary sketch of his great work; and it is this earlier and shorter treatise which contains the two famous chapters on the Aerial Ship. The aerial ship is to be buoyed up in the air by being suspended from four globes, made of thin copper sheeting, each of them about twenty-five feet in diameter. From these globes the air is to be exhausted, so that each of them, being lighter than air, will support the weight of two or three men. The ship being thus floated can be propelled by oars and sails.

Any modern reader, without asking for further specifications, can pronounce this design absurd. Lana was prevented by his vow of poverty from spending any money on experiment, so that he had to meet only argumentative objections, not those much more formidable obstacles, the ordeal of the inventor, which present themselves when a machine is theoretically perfect and will not work. The difficulties which he foresaw are real enough. The process of exhausting the air from the globes might, he thought, prove troublesome. The pressure of the atmosphere on the outer surface, it might be held, would crush or break the globes, to which he replied that that pressure would be equal on all sides, and would therefore rather strengthen the globes than break them. The ship, some might object, could not be propelled by oars; Lana thinks it could, but suggests, to comfort the objectors, that oars will rarely be necessary, for there will always be a wind. The weight of the machine and of the persons in it will fortunately prevent it from rising to heights where breathing becomes impossible. 'I do not foresee', says Lana, 'any other difficulties that could prevail against this invention, save one only, which to me seems the greatest of them all, and that is that God would never surely allow such a machine to be successful, since it would create many disturbances in the civil and political governments of mankind. Where is the man who can fail to see that no city would be proof against surprise, when the ship could at any time be steered over its squares, or even over the courtyards of dwelling-houses, and brought to earth for the landing of its crew?... Iron weights could be hurled to wreck ships at sea, or they could be set on fire by fireballs and bombs; nor ships alone, but houses, fortresses, and cities could be thus destroyed, with the certainty that the airship could come to no harm as the missiles could be hurled from a vast height.'

The extravagance of Lana's design must not be allowed to rob him of the credit of being, in some sense, the inventor of the balloon. A balloon filled with gas, and lighter than air, was in his day inconceivable; the composition of the atmosphere was unknown, and the chemistry of gases was not understood. But he had followed the physical investigations of the seventeenth century, and was well acquainted with Torricelli's demonstration of the weight of the atmosphere. The only practical way for him to make a vessel lighter than air was to empty it of the air within it, and Torricelli's invention of the barometer seemed to bring such a device within reach. The common pump begat the barometer; the barometer begat the balloon. But the enormous pressure of the atmosphere on a vessel encasing a vacuum, though Lana had triumphed over it in argument, could not be so easily dealt with in practice. The success of the balloon was delayed until, by the discovery and production of a gas lighter than air, a frail and thin envelope could be supported against the pressure from without by an equal pressure from within.

For ballooning what was chiefly necessary was a thorough knowledge of gases and of the means of producing them. The older chemistry, or alchemy, devoted all its attention, for centuries, to the precious metals, and knew nothing of gas. Medical chemistry, which succeeded it, was concerned chiefly with the curative properties of various chemical preparations. When Robert Boyle, and the investigators who came after him, put aside this age-long preoccupation with wealth and healing, and set themselves to determine, by observation and experiment, the nature of common substances, and the possibility of resolving them into simpler elements, modern chemistry began. Four states of matter, namely, earth, air, fire, and water, were recognized by the older chemists, and were by them called elements; it was the work of the eighteenth century to investigate these, and especially to separate the constituents of air and of water. In 1774 Joseph Priestley discovered oxygen. In 1782 Henry Cavendish showed that hydrogen, when burnt, produces water. At a much earlier date hydrogen had been produced by the action of acid on metals, and had been found to be many times lighter than air. Dr. Joseph Black, professor of chemistry in the University of Edinburgh, was the first to suggest, in 1767, that a balloon inflated with hydrogen would rise in the air; and the experiment was successfully tried with soap-bubbles by Tiberius Cavallo, in the year 1782.

Nevertheless, the famous first balloon, which ascended in 1783, was not filled with hydrogen, and was invented by what may be called a happy accident. The brothers Joseph and Jacques Montgolfier were the sons of a wealthy paper-maker at Annonay, not very far from Lyons. The suggestion of their balloon came to them from observing that thick opaque clouds float high in the air. Linen material was readily accessible to them at the factory, and they resolved to try whether a large balloon, some thirty-three feet in diameter, filled with smoke vapours, would rise in the air. Their experiment was successful. On the 5th of June 1783 they filled their balloon with smoke (and therefore with hot air) over a fire of chips and shavings; it rose easily, and travelled to a distance of about a mile and a half before it cooled and sank. The fame of this experiment quickly reached Paris, the centre of science and fashion, and awakened rivalry. Under the direction of Professor Charles, a well-known physicist, two brothers whose surname was Robert made from varnished silk a balloon of about thirteen feet in diameter; it was filled with hydrogen, and on the 27th of August 1783, in the presence of a large and excited assembly, it rose from the Champ de Mars and travelled some fifteen miles into the country, where it fell, and produced a panic among the peasantry. On the 19th of September Joseph Montgolfier was brought to Versailles to give a demonstration of his new invention in the presence of the King and Queen. On this occasion his balloon rose 1,500 feet into the air, carrying with it a sheep, a cock, and a duck, the first living passengers, whom it deposited unhurt when it came to ground again after a short flight. Thereafter society went balloon-mad. Pilatre de Rozier, a young native of Metz, determined to attempt an aerial voyage. During the month of October he experimented with a captive balloon of the Montgolfier type, from which he suspended a brazier, so that by a continued supply of heated air the balloon should maintain its buoyancy. On the 21st of November 1783, accompanied by the Marquis d'Arlandes, he rose in a free balloon from the Bois de Boulogne, and made a successful voyage of twenty minutes, during which time he travelled over Paris for a distance of about five miles. Ten days later, on behalf of the savants, M. Charles retorted with a voyage of twenty-seven miles, in a hydrogen balloon, from Paris to Nesle; he was accompanied by one of the brothers Robert, and when Robert left the car at Nesle the balloon, lightened of a part of its burden, rose rapidly with M. Charles to a height of two miles in the air. Most of the fittings of the modern hydrogen balloon, the hoop and netting, for instance, from which the car is suspended, and the valve at the top of the balloon for the release of the gas, were devised by Charles. The unfortunate Pilatre de Rozier met his death on the 15th of June 1785, in an attempt to cross from Boulogne to England. In order to avoid a constant wastage of hydrogen in controlling the height of the balloon, he devised a double balloon; the larger one, above, was filled with hydrogen, the smaller one, below, was worked with hot air from a brazier, on the Montgolfier principle. At a height of some three thousand feet, while it was still over French territory, the double balloon caught fire and fell flaming to the earth.

The earliest balloon ascents in England followed close upon the French experiments. On the 25th of November 1783 Count Francesco Zambeccari sent up an oil-silk hydrogen balloon, ten feet in diameter, from the Artillery Ground in Moorfields; it travelled forty-eight miles, and fell at Petworth in Sussex. On the 22nd of February 1784 a balloon of five feet in diameter, liberated at Sandwich in Kent, travelled seventy-five miles, and after crossing the Channel, fell at Warneton in Flanders. To inflate a bag with gas and let it take its chance in the air is no great achievement, but these were flights of good promise. The first person in Great Britain to navigate the air was James Tytler, a Scot, who on the 27th of August 1784 ascended in a fire-balloon, that is, a balloon filled with hot air, from Comely Gardens, Edinburgh, and travelled about half a mile. Tytler had been employed by the booksellers to edit the second edition of the _Encyclopaedia Britannica_, of which he wrote the greater part, at a salary of seventeen shillings a week; he passed his life in poverty, and his balloon adventure attracted little attention. The public mania for ballooning as a spectacle began with the ascents of Vincenzo Lunardi, secretary to the Neapolitan ambassador in England. Lunardi's first ascent, which was well advertised, was made from the Artillery Ground in Moorfields on the 15th of September 1784, in the presence of nearly two hundred thousand spectators. His hydrogen balloon, of about thirty-two feet in diameter, sailed high over London, and descended near Ware in Hertfordshire. His record of his sensations, written in imperfect English, and published in 1784 under the title of _An Account of the First Aerial Voyage in England_, deserves quotation:

'At five minutes after two, the last gun was fired, the cords divided, and the Balloon rose, the company returning my signals of adieu with the most unfeigned acclamations and applauses. The effect was that of a miracle on the multitudes which surrounded the place; and they passed from incredulity and menace into the most extravagant expressions of approbation and joy.

'At the height of twenty yards, the Balloon was a little depressed by the wind, which had a fine effect; it held me over the ground for a few seconds, and seemed to pause majestically before its departure.

'On discharging a part of the ballast, it ascended to the height of two hundred yards. As a multitude lay before me of a hundred and fifty thousand people, who had not seen my ascent from the ground, I had recourse to every stratagem to let them know I was in the gallery, and they literally rent the air with their acclamations and applause. In these stratagems I devoted my flag, and worked with my oars, one of which was immediately broken and fell from me. A pigeon too escaped, which, with a dog, and cat, were the only companions of my excursion.

'When the thermometer had fallen from 68 deg. to 61 deg. I perceived a great difference in the temperature of the air. I became very cold, and found it necessary to take a few glasses of wine. I likewise eat the leg of a chicken, but my bread and other provisions had been rendered useless by being mixed with the sand which I carried as ballast.

'When the thermometer was at fifty, the effect of the atmosphere, and the combination of circumstances around, produced a calm delight, which is inexpressible, and which no situation on earth could give. The stillness, extent, and magnificence of the scene rendered it highly awful. My horizon seemed a perfect circle; the terminating line several hundred miles in circumference. This I conjectured from the view of London; the extreme points of which, formed an angle of only a few degrees. It was so reduced on the great scale before me, that I can find no simile to convey an idea of it. I could distinguish Saint Paul's and other churches, from the houses. I saw the streets as lines, all animated with beings, whom I knew to be men and women, but which I should otherwise have had a difficulty in describing. It was an enormous beehive, but the industry of it was suspended. All the moving mass seemed to have no object but myself, and the transition from the suspicion, and perhaps contempt, of the preceding hour, to the affectionate transport, admiration and glory of the present moment, was not without its effect on my mind. I recollected the puns[3] on my name, and was glad to find myself calm. I had soared from the apprehensions and anxieties of the Artillery Ground, and felt as if I had left behind me all the cares and passions that molest mankind.

[Footnote 3: In some of the papers, witticisms appeared on the
affinity of Lunatic and Lunardi.]

'Indeed, the whole scene before me filled the mind with a sublime pleasure, of which I never had a conception. The critics imagine, for they seldom speak from experience, that terror is an ingredient in every sublime sensation. It was not possible for me to be on earth in a situation so free from apprehension. I had not the slightest sense of motion from the Machine, I knew not whether it went swiftly or slowly, whether it ascended or descended, whether it was agitated or tranquil, but by the appearance or disappearance of objects on the earth. I moved to different parts of the gallery, I adjusted the furniture, and apparatus, I uncorked my bottle, eat, drank, and wrote, just as in my study. The height had not the effect, which a much lesser degree of it has near the earth, that of producing giddiness. The broomsticks of the witches, Ariosto's flying-horse, and even Milton's sunbeam, conveying the angel to the earth, have all an idea of effort, difficulty, and restraint, which do not affect a voyage in the Balloon.

'Thus tranquil, and thus situated, how shall I describe to you a view, such as the ancients supposed Jupiter to have of the earth, and to copy which there are no terms in any language. The gradual diminution of objects, and the masses of light and shade are intelligible in oblique and common prospects. But here every thing wore a new appearance, and had a new effect. The face of the country had a mild and permanent verdure, to which Italy is a stranger. The variety of cultivation, and the accuracy with which property is divided, give the idea ever present to a stranger in England, of good civil laws and an equitable administration; the rivers meandering; the sea glist'ning with the rays of the sun; the immense district beneath me spotted with cities, towns, villages, houses, pouring out their inhabitants to hail my appearance: you will allow me some merit at not having been exceedingly intoxicated with my situation.

'The interest which the spectators took in my voyage was so great, that the things I threw down were divided and preserved as our people would relicks of the most celebrated saints. And a gentlewoman, mistaking the oar for my person, was so affected with my supposed destruction, that she died in a few days.'

* * * * *

For many months after this the Flying Man was the chief topic of conversation in the town. Even in the previous year reports of the French ascents had produced a fever of excitement in London. 'Balloons', said Horace Walpole, writing in December 1783, 'occupy senators, philosophers, ladies, everybody.' All other interests yielded precedence. Miss Burney's _Cecilia_ was the novel of the season, but it had to give way. 'Next to the balloon,' said Mrs. Barbauld, in a letter written in January 1784, 'Miss Burney is the object of public curiosity.' A few weeks earlier, Dr. Johnson passed the day with three friends, and boasted to Mrs. Thrale that no mention had been made by any of them of the air balloon, 'which has taken full possession, with a very good claim, of every philosophical mind and mouth'. Some days after Lunardi's first ascent Johnson wrote to a friend, 'I had this day in three letters three histories of the flying man in the great Ballon. I am glad that we do as well as our neighbours.' Three letters were enough, and on the same day Johnson wrote to Sir Joshua Reynolds, 'Do not write about the balloon, whatever else you may think proper to say'. On the 29th of September 1784 Lunardi's balloon caught fire by accident, and was burnt on the ground. Johnson's quiet and sensible comment is conveyed in a letter to his friend Dr. Brocklesby, on the 6th of October: 'The fate of the balloon I do not much lament: to make new balloons is to repeat the jest again. We now know a method of mounting into the air, and, I think, are not likely to know more. The vehicles can serve no use till we can guide them; and they can gratify no curiosity till we mount with them to greater heights than we can reach without; till we rise above the tops of the highest mountains, which we have yet not done. We know the state of the air in all its regions, to the top of Teneriffe, and therefore, learn nothing from those who navigate a balloon below the clouds. The first experiment, however, was bold, and deserved applause and reward.'

Johnson died in December of that same year; the balloon had made its appearance just in time for his comments. Another critic, Horace Walpole, was in two minds about balloons. Sometimes they seemed to him 'philosophic playthings'. He was growing old, and did not care to spend his time in 'divining with what airy vehicles the atmosphere will be peopled hereafter, or how much more expeditiously the east, west, or south will be ravaged and butchered, than they have been by the old clumsy method of navigation'. Yet in spite of his elegant indifference, he could not help being interested; and some of his divinations come very near to the truth. He pictures Salisbury Plain, Newmarket Heath, and all downs, arising into dockyards for aerial vessels; and he professes himself willing to go to Paris by air, 'if there is no air sickness'. The best defence of the new invention was spoken by Benjamin Franklin, who when he was asked in Paris, 'What is the use of balloons?' replied by another question--'What is the use of a newborn infant?'

The infancy of the balloon lasted long; indeed, if lack of self-control be the mark of infancy, the balloon was an infant during the whole of the nineteenth century. In the early days, new achievements, in distance or height, kept public expectation alive. Jean Pierre Blanchard, a French aeronaut, and rival of Lunardi, succeeded, on the 7th of January 1785, in crossing the English Channel from Dover. Thereafter ascents became so numerous that it is impossible to keep count of them. Glaisher, writing about 1870, says that the most remarkable ascent of the century was that fitted out by Robert Hollond, Esq., M.P. The balloonist was Charles Green, and they were accompanied by Mr. Monck Mason, who published an account of the voyage. In Mr. Green's balloon, afterwards called the _Great Nassau_, they left Vauxhall Gardens on the afternoon of Monday, the 7th of November 1836, with provisions to last a fortnight. They were soon lost in the clouds, and after crossing the sea, had no very clear idea of what country they were over. After eighteen hours' journey, fearing that they had reached Poland or Russia, they came to earth, and found that they had travelled five hundred miles, to the neighbourhood of the town of Weilburg, in the duchy of Nassau. Charles Green was the most experienced aeronaut of his time; he was the first to use coal-gas in place of hydrogen, and he was the inventor of the guide-rope, which is dropped from a balloon to allow her to be secured by a landing party, or is trailed on the ground to reduce her speed and to assist in maintaining a steady height.

The dangers of the balloon were diminished by the labours of scientific men, but its disabilities remained. No one who travelled in a balloon could choose his destination. The view of the earth, and of the clouds, obtainable from a height, was beautiful and unfamiliar, but in the absence of any specific utility the thing became a popular toy. In public gardens a balloon could be counted on to attract a crowd, and the showman soon gave it its place, as a miracle of nature, by the side of the giant and the dwarf, the living skeleton, and the fat woman. A horse is not seen to advantage in the car of a balloon, but it is a marvel that a horse should be seen there at all, and equestrian ascents became one of the attractions of the Cremorne Gardens in 1821.

It was not until 1859 that an organized attempt was made to reclaim the balloon for the purposes of science. In that year a committee, appointed by the British Association to make observations on the higher strata of the atmosphere, met at Wolverhampton. Volunteers were lacking until, in 1862, James Glaisher, one of the members of the committee, declared his willingness to prepare the apparatus and to make the observations from a balloon. Glaisher had spent many years on meteorological observation, in Ireland, at Cambridge University, and at the Royal Observatory, Greenwich. He proposed to investigate the effect of different elevations on the temperature of the dew-point; on the composition and electrical condition of the atmosphere, and on the rate and direction of the wind currents in it; on the earth's magnetism, and the solar spectrum; on sound, and on solar radiation. From 1862 to 1866 he made twenty-eight ascents, with Henry Coxwell as his balloonist. The most famous of these was from Wolverhampton on the 5th of September 1862, when Glaisher claimed to have reached a height of fully seven miles. After recording a height of 29,000 feet Glaisher swooned; Coxwell lost the use of his limbs, but succeeded in pulling the cord of the valve with his teeth. When Glaisher swooned the balloon was ascending rapidly; when he came to, thirteen minutes later, it was descending rapidly, and the height that he claimed was an inference, supported by the reading of a minimum thermometer. Critics have pointed out that his calculations made no allowance for the slackening of the upward pace of the balloon as it neared its limit, nor for the time it would take, with the valve feebly pulled, to change its direction and acquire speed in its descent. They are inclined to allow him a height of about six miles, which is a sufficiently remarkable achievement.

All these ascents, though they proved that the balloon had a certain utility for the exploration of the upper reaches of the atmosphere, did little or nothing for aerial navigation. The great vogue of the balloon distracted attention from the real problem of flight. That problem was not abandoned; a number of men, working independently, without any sort of public recognition, made steady advance during the whole course of the nineteenth century. By the end of the century, three years before flight was achieved, those who were most deeply concerned in the attempt knew that success was near. The great difficulty of scientific research lies in choosing the right questions to ask of nature. Every lawyer knows that it is easy to put a question so full of false assumptions that no true answer to it is possible; and many a laborious man of science has spent his life in framing such questions, and in looking for an answer to them. The contribution of the nineteenth century to the science of flight was that it got hold of the right questions, and formulated them more or less exactly, so that the answers, when once they were supplied by continued observation and experiment, were things of value.