INTRODUCTION
Of silver wings he took a shining pair,
Fringed with gold, unwearied, nimble, swift;
With these he parts the winds, the clouds, the air,
And over seas and earth himself doth lift.
Thus clad he cuts the spheres and circles fair,
And the pure skies with sacred feathers clift;
On Lebanon at first his feet he set
And shook his wings with rosy may-dews wet.
Tasso, Canto I, XIV.
How beautiful! May we hope ever to journey thus, on wings actuated by human power? It is an old question, once dear to the philosopher and fool alike, but now important mainly to the fool. Or say more kindly it is the affair of untechnical inventors—the amateur, the rustic, the man of chimerical dreams. For the wise aëronaut now numbers that project among the roseate illusions of his youth.[1]
Ovid relates a story, doubtless credible in his day, of a clever craftsman who with his son flew bravely aloft, the very first time they put on wings. Daedalus, a Greek architect, having fled from Athens for murder, went with his son Icarus to the island of Crete, where he built the celebrated labyrinth for Minos, the king. He offended that monarch and was cast into prison. In order to escape he made wings for himself and his son, with which they flew far over the sea. But Icarus, in his elation, soared too near the sun, ruined his wings, fell into the sea and was drowned. For proof of this we have the Icarian Sea, named after the unfortunate boy. Also we have Ovid’s charming poem:
In tedious exile now too long detain’d
Daedalus languish’d for his native land;
The sea foreclosed his flight, yet thus he said;
“Though earth and water in subjection laid,
O cruel Minos, thy dominion be,
We’ll go through air; for sure the air is free.”
Then to new arts his cunning thought applies,
And to improve the work of nature tries.
A row of quills, in gradual order placed,
Rise by degrees in length from first to last;
As on a cliff the ascending thicket grows;
Or different reeds the rural pipe compose:
Along the middle runs a twine of flax,
The bottom stems are join’d by plaint wax;
Thus, well compact, a hollow bending brings
The fine composure into real wings.
His boy, young Icarus, that near him stood,
Unthinking of his fate, with smiles pursued
The floating feathers, which the moving air
Bore loosely from the ground, and wafted here and there:
Or with the wax impertinently play’d,
And with his childish tricks the great design delay’d.
The final masterstroke at last imposed,
And now, the great machine completely closed;
Fitting his pinions on, a flight he tries,
And hung self-balanced in the beaten skies.
Then thus instructs his child: “My boy, take care
To wing your course along the middle air:
If low, the surges wet your flagging plumes;
If high, the sun the melting wax consumes.
Steer between both: nor to the northern skies,
Nor South Orion, turn your giddy eyes,
But follow me; let me before you lay
Rules for the flight, and mark the pathless way.”
Thus teaching, with a fond concern, his son,
He took the untried wings, and fix’d them on:
But fix’d with trembling hands; and, as he speaks,
The tears roll gently down his aged cheeks;
Then kiss’d, and in his arms embraced him fast,
But knew not this embrace must be the last;
And mounting upward, as he wings his flight,
Back on his charge he turns his aching sight;
As parent birds, when first their callow care
Leave the high nest to tempt the liquid air;
Then cheers him on, and oft, with fatal art,
Reminds the stripling to perform his part.
These, as the angler at the silent brook,
Or mountain shepherd leaning on his crook,
Or gaping ploughman, from the vale descries,
They stare, and view them with religious eyes,
And straight conclude them gods; since none but they
Through their own azure skies could find a way.
Now Delos, Paros, on the left are seen,
And Samos, favour’d by Jove’s haughty queen;
Upon the right, the isle Lebynthos named,
And fair Calymne for its honey famed.
When now the boy, whose childish thoughts aspire
To loftier aims, and make him ramble higher,
Grown wild and wanton, more embolden’d flies
Far from his guide, and scars among the skies:
The softening wax, that felt a nearer sun,
Dissolved apace, and soon began to run:
The youth in vain his melting pinion shakes,
His feathers gone, no longer air he takes:
“Oh! father, father!” as he strove to cry,
Down to the sea he tumbled from on high,
And found his fate; yet still subsists by Fame,
Among those waters that retain his name.
The Father, now no more a father, cries:
“Ho, Icarus! where are you?” as he flies;
“Where shall I seek my boy?” he cries again,
And saw his feathers scatter’d on the main;
Then cursed his art; and funeral rites conferr’d
Naming the country from the youth interr’d.
How tender and apprehensive that gentleman’s farewell, compared with the modern vogue in like circumstances! Of the two Americans at Berlin who fell four thousand feet in a balloon, it is not recorded that they either kissed or wept.[2] But some Teutonic Ovid may yet adorn the tale with quaint embellishments.
Taking more serious note of Daedalus, it will be observed that he has had few imitators. It is because he never really flew, and no one else can fly, in such manner. That is to say, no man can achieve practical flight on wings actuated by his own muscular power. It may be physically possible for an athlete putting forth herculean energy for a few seconds to sustain himself on wings of enormous spread; but in every lightest zephyr he would be as helpless as a thistle seed.
The actual area of wing required for a man of given weight and power may be roughly estimated; at least its lower limit of size can be determined. Lord Rayleigh,[3] on purely theoretical ground, has computed that a man operating a screw propeller 280 feet in diameter, moving without frictional loss, could sustain his weight for a period of eight hours a day at a comfortable rate of work. But that estimate does not include the weight of the propeller. By exerting ten times his normal power the man could support his weight with a 28-foot propeller.
The physical basis of the computation is the same for every type of flyer, whether bird, man, or machine. Its weight must be sustained by hurling the air downward. The humming bird in its aërial pause, the bee floating beside a blossom, rests on a down-driven column of air. The home-gliding eagle at dusk may encounter a medium in stillest repose, but he leaves behind him a down-flowing wake, viewless, maybe, but none the less real. In all cases the downward impulse per second given to the air must equal the weight supported by its reaction. If the wings be very extensive a proportionate mass of air may be struck down, and yield support with so much the less exertion.
Horizontal flight promises little more than direct screw lift, with the feeble energy of the human muscle. The best modern aëroplanes carry less than 100 pounds per horse power, while an average man must weigh, with a light machine, not less than 200 pounds, and must therefore exert upwards of two horse power during flight. Such an output of energy would exhaust a powerful athlete in a few seconds. Hence from every point of view it appears that Daedalean flight, which still has its devotees in some form, was and always will be utterly impracticable.
Ruskin finds another objection to the disciples of the winged arm. In his disquisition on the equilibrium of angels he complains that those of the traditional two-wing type are devoid of gravitational balance. Such creatures vex the imagination with apprehensions for their stability; hence they cannot be entirely beautiful. The centroid of an angel is in the small of its back, whereas the center of wing support is well forward; therefore the horizontal poise is absurd and unæsthetic. The scientific artist, consequently, views with pain the picture of a fair lady floating level through space supported only at her front end.
Milton adroitly forestalls this censure. In the conception of his glorious Raphael, he provides consummately for uniform and adequate support:
Six wings he wore, to shade
His lineaments divine; the pair that clad
Each shoulder broad, came mantling o’er his breast
With regal ornament; the middle pair
Girt like a starry zone his waist, and round
Skirted his loins and thighs with downy gold,
And colors dipped in Heaven; the third his feet
Shadowed from either heel with feathered mail,
Sky-tinctured grain. Like Maia’s son he stood,
And shook his plumes, that heavenly fragrance filled
The circuit wide.
Leonardo da Vinci, who was a gifted engineer as well as an artist, devised a flying gear for man which shows some dynamic improvement over the mechanism of the old-time angels, flying gods, and hobgoblins. As shown in the accompanying sketch, it provided for gravitational balance by use of an expanding tail projecting well to the rear. Moreover, the propulsion was to employ both arms and legs. This design is considered very remarkable for the time in which it was produced, probably a few years before the discovery of America; and yet it is but one of Da Vinci’s quaint aëronautical inventions, as will appear later.
A less futile scheme of aviation may be to saddle the birds. If one eagle can float a child, a few may possibly carry a man. They are physically able; they are inexpensive; they are unwearied, nimble, swift. Some harness, some tuition may be required; but these come to the industrious. Apparently, such locomotion is a sport worth developing; a royal art, if you please; for who would not course the sky in a purple palanquin borne by imperial eagles?
Kai Kaoos, the King of Persia, is credited with a voyage of this kind, as described in the Shah-Nemeh, or King-Book, written in the tenth century:
“To the king it became a matter of great concern how he might be enabled to ascend the heavens, without wings; and for that purpose he consulted the astrologers, who presently suggested a way in which his desires might be successfully accomplished.
Fig. 1.—Da Vinci’s Designs for Human Flying-Gear.
“They contrived to rob an eagle’s nest of its young, which they reared with great care, supplying them with invigorating food.
“A frame of aloes-wood was then prepared, and at each of the four corners was fixed perpendicularly a javelin surmounted on the point with the flesh of a goat. At each corner again one of the eagles was bound, and in the middle the king was seated with a goblet of wine before him. As soon as the eagles became hungry they endeavored to get at the goat’s flesh upon the javelins, and by flapping their wings, and flying upwards they quickly raised the throne from the ground. Hunger still pressing on them, and still being distant from their prey, they ascended higher and higher in the clouds, conveying the astonished king far beyond his own country. But after a long and fruitless exertion, their strength failed them, and, unable to keep their way, the whole fabric came tumbling down from the sky, and fell upon a dreary solitude in the Kingdom of Chin, where Kai Kaoos was left a prey to hunger, alone, and in utter despair.”
One might prefer a single bird, which could be ridden bareback by a man or woman of common equestrian skill. The early philosophers, therefore, sought with some care for such a creature. The following is related by Bishop Wilkins:
“Cardan and Scaliger doe unanimously affirm, that there is a bird amongst the Indians of so great a bignesse, that his beak is often used to make a sheath or scabbard for a sword. And Acosta tells us of a fowl in Peru called Condores, which will of themselves kill and eat up a whole calf at a time. Nor is there any reason why any other body may not be supported and carried in the air, though it should as much exceed the quantity of these fowls as they do the quantity of a flie. Marcus Polus mentions a fowl in Madagascar which he cals a Ruck, the feathers of whose wings are 12 paces, or threescore foot long, which can with as much ease scoop up an elephant as our kites do a mouse. If this relation was anything credible, it might serve as an abundant proof for the present quaere.”
As the roc has proved a myth, one questions whether a saddle bird may not be evolved by judicious breeding. But opposed to this is the square-cube law of the Greek geometer, by which a learned geologist demonstrated that nature has reached the limit of her resources in the production of large flyers, the ostrich, for example, being too bulky to navigate at all. As a last resource, then, the human dwarf may breed his weight downward to accommodate the bird. Assuredly, the most powerful flyer can carry the lightest human dwarf without difficulty.
Such aërial cavalry has been projected occasionally, and if fairly developed might have interesting employment. Its military value, to say nothing of its civil uses, would be considerable. An aërial scout that could hide in a tree top, or small cloud, then flit home with full intelligence of the enemy, would be effective and unique. In aggressive warfare it would serve the plan of that ingenious Englishman who proposes to repel a German invasion by dispatching birds to peck holes in the enemy’s war balloons. But here the dwarf might be omitted, if the birds were taught to have a definite interest in attacking aërial cruisers with their beaks, or with steel-armed spurs like those of the Spanish fighting cock, or with talons treated chemically to strike fire. Sparrows with sulphur-pointed toes could easily annihilate an aërial squadron at all combustible.
Recurring to the geologist, it may be added that, having discovered the major limit of feathered navigators, he concluded, as a corollary, that human flight is forever impossible. That was in the latter eighties. In 1901 a versatile astronomer adduced the same law to prove that an aëroplane could not be made to carry a man. Presently, learning that this had been achieved, he proved, in a second mellifluous paper, that an aëroplane could not carry, several men.[4] Having erred twice, he wrote a final article announcing that a flyer is fatuous, anyhow, because she cannot repair her engines in the sky!
Fig. 2.—A Possible Air-scout.
Of the numerous daring and industrious inventors who, during remote generations, have launched themselves in the air on some species of rigid or vibrant wings, a few were men of considerable equipment in philosophy, or mechanics, and enjoyed a sufficient measure of success to deserve passing notice; though it seems that no man before the middle of the eighteenth century made a permanent contribution to the real art of mechanical flight, if we except the ingenious suggestive devices of Leonardo da Vinci. However skilfully their flying apparatus may have been planned, or operated, the results were lost to the world, due to inaccurate or inadequate description. Such inventors were J. B. Dante, in the fifteenth century, and the Marquis de Bacqueville, in the seventeenth. Each of these made one, or more, considerable flights, if we may credit the unwavering testimony of their contemporaries; but neither has left a sketch of his device, nor a school of followers to continue his spectacular practice.
Jean-Baptiste Dante, a shrewd observer and profound mathematician, who flourished toward the end of the fifteenth century, a contemporary of Da Vinci and Columbus, is reported by the historians of that day to have sailed successfully through the air on nonvibrant wings designed by himself after a careful study of the great soaring birds. Perching above a steep crag on the shore of Lake Trasimene, he set his wings to the wind at a nice angle, as one sets the sails of a vessel; then, lifted by the swelling breeze, he rose grandly aloft and floated far over the waters. Again and again he repeated the experiment, until the fame thereof secured for him a request to make the demonstration at the marriage fêtes of the illustrious general, Barthelmi Alviano. He accepted the invitation, and, starting from the top of the highest tower in the city of Perugia, he sailed over the public square, and balanced himself for a long time in space, amid the shouts and acclamations of the multitude, attracted to Perugia by the novelty of his performance. But, sad to relate, the very first time he performed these wonderful maneuvers above the solid ground instead of the lake, one of the levers used to alter the impact angle of his wings gave way, disturbing his aërial poise, and causing him to pitch down upon Notre Dame church, breaking one of his legs. After this he taught mathematics at Venice, where he died of fever at the age of forty years.
In 1742, the Marquis de Bacqueville, at the age of sixty-two years, announced that on a certain day he would fly from his house on the Seine, traverse the river, and land in the Garden of the Tuileries. A great multitude assembled, crowding both shores and the two bridges. At the appointed moment the Marquis appeared with his pinions, and launched himself from the terrace. He sailed forth in majestic and serene poise, on graceful wings not unlike those of the traditional angels. He was gliding directly toward the Tuileries, and he enjoyed a happy cruise quite to the middle of the river. Then something happened; his movements became fitful and uncertain; he plunged downward and broke his leg on a laundry boat. The reason for his stopping there can only be surmised, for he had nothing to report. He did not quite fulfil his program, but he flew nine hundred feet delightfully, and he landed without getting wet.
Commentators have marveled as to the nature of the mechanism used by Dante and by De Bacqueville. Historians have strongly attested the fact of the flights, but have overlooked the means. The inventors must have employed aërial gliders of some kind, for adequate motive power was not available before the end of the nineteenth century. Even as an experiment in gliding, or soaring, the achievement of Dante was most daring and wonderful, eclipsing the best performances up to the twentieth century. It is strange that in that period of science the survivor of such an experience, and a college professor, should not have left to the world a careful account of such an extraordinary performance. The alleged flights, however, were unquestionably feasible, even in that remote period, for the construction of an aërial glider is a simple task not beyond the capacity of craftsmen in the fifteenth century A.D., or even the fifteenth century B.C., directed by a skilful designer.
Besides the wing-armed scheme of flight credited to Daedalus, and contemplated by Da Vinci, various other plans were evolved in succeeding years. Aërial chariots and flying machines were devised for the more advantageous use of muscular energy. In all these, of course, the passenger could be both power plant and captain of the ship.
One of the earliest authenticated devices of this kind was the invention of Blanchard, described by him in the Journal de Paris, August 28, 1781, nearly two years before the invention of the hot-air balloon, of which he became later an enthusiastic votary. As his device is but one of a large number that appeared before the close of the nineteenth century, and the advent of light motors, the reader who wishes fuller acquaintance with man-driven airships may be referred to Mr. Chanute’s book, entitled Progress in Flying-Machines, which describes a large variety of such inventions, and discusses the merit and weakness of each.
Blanchard prefaces the description of his machine by answering some criticisms of his project, apparently ventured by his neighbors. “They object to me,” he writes, “that flying is not the business of man, but rather of the feathered birds. I reply that feathers are not at all necessary to the bird for flight; any fabric suffices. The fly, the butterfly, the bat, etc., fly without feathers and with fanlike wings of material resembling horn. It is, then, neither the material nor the form that causes flight, but the volume and the celerity of the movement, which should be as lively as possible.
“They object, moreover, that a man is too heavy to lift himself alone with wings, much less in a vessel which of itself presents enormous weight. I reply that my ship is extremely light; as to the man’s weight, I pray that attention be given to that which M. de Buffon says in his Histoire Naturelle, on the subject of the condor; this bird, though of enormous weight, easily lifts a two-year-old heifer weighing at least a hundred pounds, the whole with wings of about thirty to thirty-six feet expanse.”
He then describes the vessel as a little ship four feet long by two feet wide, having on either side two posts, each supporting a wing ten feet long, the whole forming a parasol twenty feet in diameter. The construction was illustrated by an engraver, who had seen the vessel and was convinced of its practicability. In conclusion, the inventor writes that people shall see him cleave the air with more speed than the crow, and that without losing his breath, being protected by a pointed mask of peculiar construction. But, as he failed to make good his promises, he was subjected to ridicule, as well as praise, by the local press, one of the caricatures portraying him in the act of making an ascension before a concourse of bulging-eyed savants and long-eared jackasses, wearing spectacles to accentuate the appearance of wisdom and solemnity.
The scientific coterie of Paris were apparently impatient of the attention shown Blanchard by the press and people. Accordingly, in May, 1782, the distinguished astronomer, De Laland, of the French Academy, administered a mild rebuke to the editors of the Paris Journal. “Gentlemen,” he wrote, “you have given so much time to air ships and divination rods that one might eventually think that you believe in these follies, or that the scientists who coöperate with your journal have nothing to say to dispel these absurd pretensions. Permit me, therefore, gentlemen, to occupy some lines in your journal to assure your readers that if the savants are silent it is only because of their contempt.
Fig. 3.—Blanchard’s Flying-machine.
“It has been demonstrated to be impossible for a man in any manner whatever to raise himself, or even to sustain himself, in the air. M. Coulomb, of the Academy of Sciences, at one of our meetings a year ago, read a paper in which he showed clearly, by calculating the power of a man, determined by experiments, that he would require wings two or three thousand feet long moved three feet per second; hence no one but an ignoramus would make an attempt of this kind.”
Not many months after this lofty deliverance, Blanchard took De Lalande up in a balloon—“the dead borne by the dumb.”
Coulomb’s calculation that a man’s pinions should be half a mile long must have been discouraging to those inventors who believed in him; for, granting that such wings could lift a man, who could lift the wings? And at that date the steam engine was only beginning to develop; the petroleum engine was hardly thought of. No wonder that people turned eagerly to the balloon when it finally appeared.
There has been some controversy as to what person first clearly conceived a feasible design for a balloon. The conception was certainly not new to the world in 1783, when Joseph Montgolfier made his classical experiment. Indeed, prior to that date three distinct principles of aërial flotation had been entertained by natural philosophers; first, that a boat could be so formed of heavy material as to ride on the upper surface of the atmosphere, as a metallic vessel floats on the water; second, that a closed hull, comprising a partial, or complete, vacuum, could be made light enough to rise; third, that a bag could be made buoyant by filling it with material lighter than air. Of course, it is now clear to men versed in mathematics that only the light-gas principle is mechanically applicable. But the vacuum principle still has adherents among inventors who are too “practical” to understand, or trust, exact computation; and the first principle, though now discarded by everyone, was plausible enough, even to accomplished scientific men, before the experiments of Torricelli, and his invention of the barometer, made in 1643. It may, therefore, be interesting to notice some of the proposed, or reported, air ships based upon these various principles. The following is from Mendoza, Viridario, libri III, probl. 47:
“Any brass vessel full of air, which otherwise would sink, is sustained on the surface of the water, though naturally of much greater specific gravity; consequently a wooden ship, or one of any other material, placed on the summit of an aërial superficies and filled with elementary fire, will be sustained in that position till the gravity of the vessel becomes greater than the sustaining power of the fire it contains.”
This is a clear scientific exposition of a plan for navigating the atmosphere on its upper surface, assuming a distinct upper surface to exist. In commenting on this passage, the Jesuit Schottus, in his Magia Universalis, uses an expression which indicates his belief that a vessel can be made to float in the air by filling it with ether, or the element of fire. He says:
“In such terms has this matter been treated by Mendoza (died 1626); nor is there any improbability involved in his view, whether the element of fire be placed above the air, or, what is still more credible, the ether—that is, the purest air. Although any wood, iron, copper, lead, and such like metals are weightier than an equal volume of water, and for that reason will sink in water when placed there alone, yet if fabricated into hollow shapes, and filled with our impure and heavy air, they swim upon waters, and are adapted to the construction of ships, and are sustained by water without danger of immersion; thus, although these bodies are of greater specific gravity than our air, nevertheless, when shaped into a boat and filled with that very light material, they can float in the air, and are suitable material for the construction of small ships, because the entire work composed of the little ship and the ether can be made lighter than an equal volume of our impure air, even in the highest region.”
As Roger Bacon proposed a similar device in 1542, Mendoza’s was not entirely new and may not have been original. Bacon, describing his aërial vessel, says: “It must be a large, hollow globe of copper, or other suitable metal, wrought extremely thin, in order to have it as light as possible. It must then be filled with ‘ethereal air or liquid fire,’ and then be launched from some elevated point into the atmosphere, where it will float like a vessel on water.”
In the year 1646 another learned Jesuit published a book, Ars Magna Lucis et Umbræ in Mundo, in which he relates an episode indicating that one of his order had made use of a hot-air balloon to intimidate some ignorant pagans. The following demonstration, if reported by a modern missionary, would be accepted as a matter of course; why, then, should we gravely question the story, since it describes an achievement quite possible at the time, assuming that the necessary materials were available? And even assuming the report to be fictitious, still it is a scientific description of a practicable hot-air balloon, presented and credited by a learned scholar and accomplished mathematician more than a century before the balloon was publicly exhibited by the illustrious Frenchmen. He writes:
“I know that many of our fathers have been rescued from the most imminent dangers amongst the barbarians of India by such inventions. These were cast into prison, and whilst they continued ignorant of any means of effecting their liberation, some one, more cunning than the rest, invented an extraordinary machine, and then threatened the barbarians, unless they liberated his companions, that they would behold in a short time some extraordinary portents, and experience the visible anger of the Gods. The barbarians laughed at the threat. He then had constructed a dragon of the most volatile paper, and in this he enclosed a mixture of sulphur, pitch, wax, and so artistically prepared all his materials, that, when ignited, it would illumine the machine, and exhibit the following legend in their vernacular idiom, The Anger of God. The body being formed and the ingredients prepared, he then affixed a long tail, and committed the machine to the heavens, and, favored by the wind, it soared aloft towards the clouds. The spectacle of the dragon so brilliantly lit was terrific. The barbarians, beholding the unusual motion of the apparition, were smitten with the greatest astonishment, and now, remembering the threatened anger of Deity and the words of the father, they were in fear of expiating the punishment he had prognosticated for them. Therefore, without delay, they threw open the gates, they suffered their prisoners to go forth in peace and enjoy their freedom. In the meantime the fire seized on the machine and set it in a blaze, and with an explosion, which was interpreted as an expiring declaration of satisfaction, it, apparently of its own accord, vanished from sight, as if it had accomplished its supernatural mission. Thus the fathers, through the apprehension which this natural manifestation inspired, obtained that which could not be purchased with a large amount of gold.”
Perhaps the reader will permit another anecdote, not entirely for its scientific value, but because he may like to compare the attitude of people toward aërial navigation in the dark ages with the attitude of his neighbors at the opening of the twentieth century. In two histories by Jef le Ministre and De Colonia, of the town of Lyons, the following account is given:
“Toward the end of Charlemagne’s reign, persons who lived near Mount Pilate in Switzerland, knowing by what means pretended sorcerers traveled through the air, resolved to try the experiment, and compelled some poor people to ascend in an aërostal. This descended in the town of Lyons, where they were immediately hurried to prison, and the mob desired their death as sorcerers. The judges condemned them to be burned; but the Bishop Agobard suspended the execution, and sent for them to his palace, that he might question them. They answered: ‘Qu’ils sont du pays meme, que des personnes de consideration les ont forcés de se laisser conduire, leur promettent qu’ils verroient des chose merveilleuses; et qu’ils sont veritablement descendu par l’air.’ Agobard, though he could not believe this fact, gave credence to their innocence, and allowed them to escape. On this occasion he wrote a work on the superstition of the time, in which he demonstrated the impossibility of rising in the air; that it is an error to believe in the power of magic; and that it has its existence in the credulity solely of the people.”
One of the first men to make an aërial model like a fire balloon was the celebrated Brazilian, Bartholomeo-Lourenco de Gusmao, who in his day was nicknamed the “flying man,” and who is reported to have made a remarkable experiment in aërial locomotion at Lisbon. The following account of it is found in a manuscript of Ferreira:
“Gusmao made his experiment on August 8, 1709, in the court of the Palace of the Indies, before his majesty and a large and distinguished audience, with a globe which lifted itself softly to the height of the hall of the Ambassadors, then descended in like manner. It was borne up by certain materials which burned and which the inventor himself had ignited.”
All the details of this description, which was written a generation or more before the Montgolfier experiment, suggest at once a hot-air balloon. But a note printed in 1774 and cited by Cavallo explains that the globes must have been transported by gas. It is certain that early in 1709 Gusmao applied to the King for a patent and sole right to some such invention, desiring an injunction and severe penalty against all infringements. The application sets forth a machine capable of journeying through the air faster than over land or sea, competent to carry messages five or six hundred miles a day to troops, or the most distant countries, and even adequate to explore regions about the poles. Quite a modern promoter Señor Gusmao. The King in reply issued the following decree:
“Agreeably to the advice of my council, I order the pain of death against the transgressor. And in order to encourage the suppliant to apply himself with zeal toward improving the machine which is capable of producing the effects mentioned by him, I also grant him the first Professorship of Mathematics in my University of Coimbra, and the first vacancy in my College of Barcelona, with the annual pension of 600,000 reis during his life.”
The “patent” seemed liberal enough, and yet Gusmao never resumed his aërial experiments. He was accused of magic, and may have feared persecution on that account; accordingly he engaged in naval construction till 1724, when he left Portugal.
The first vacuum balloon was proposed by the Jesuit father, Francis Lana, and described in his book Podromo dell’Arte Maestra Brecia, which appeared in 1670. Though not a practical project like Gusmao’s, it was very ingenious, and marks an interesting phase in the evolution of the fundamental idea of the air ship, or “balloon” as it was called by the inventor, who then coined the word now in common use. Lana proposed to use four copper spheres each 25 feet in diameter and 1/225 inches in wall thickness, quite well exhausted of air, to give ascensional force which he computed at 1,200 pounds aggregate for the four spheres. From these he would suspend the passengers in a boat having a mast and sail to propel the ship in time of favorable wind. Having computed the buoyancy according to well-known physical laws, he could see no possible objection to his project “unless,” he writes, “it be that God would never permit this invention to be practically applied, in order to prevent the consequences that would ensue therefrom in the civil and political government of men.”
Fig. 4.—Lana’s Proposed Vacuum Balloon.
Of recent years inventors having less delicate scruples about embarrassing Providence, have revived Lana’s project with improvements. It has been proposed to replace the sail by a motor-driven propeller, and to ensure the hull against collapse from the prodigious external air pressure—a ton per square foot—by ample internal bracing. Even within the past twelve months this scheme has been soberly advocated by several technical journals and by the author of an elaborate book on aërial warfare. To a mathematician this is amusing, when not too pathetic; for it can be rigorously proved that no vacuum balloon of present day material, whatever its design, can possibly resist crushing if made light enough to float.
In 1887 Walter Wellman described in the Associated Press a steel vacuum balloon 144 feet in diameter and 654 feet long in which a Chicago doctor proposed to carry passengers to the North Pole, at incredible speed, if they would furnish him $130,000 to meet the expenses of construction. “Here is a most excellent opportunity,” wrote Wellman, “for all who would like to win fame by being one of the party which shall set foot upon that icy ignis fatuus of many nations and two centuries.” Two decades later Mr. Wellman organized, after his own ideas, an aërial expedition to the North Pole; but he no longer favored starting from Chicago in a vacuum balloon with a party of stockholders.
It may be added that the inventor of the great steel vacuum balloon, after organizing the Trans-Continental Aërial Navigation Company, and failing to raise all of the $130,000, sought aid from the national government. Here was an interesting situation; a doctor ignorant of mechanics, with the plans for a mammoth and impossible balloon, appealing for aid to a congress, supremely shy of air ships, even though recommended by its ablest military advisers. But in this case there was a capable lobby. The bill for this physically impossible balloon actually passed the House, and was finally defeated only by the timely effort of a few scientific men who, by easy calculation, proved the absurdity of the invention. As the reader may like to see a mathematical proof of the impossibility of a vacuum balloon, since such projects arise frequently, the argument is given in [Appendix I].
PART I
GROWTH OF AËROSTATION
CHAPTER I
EARLY HISTORY OF PASSIVE BALLOONS
Oh, that I could as smoke arise,
That rolls its black wreathes through the air;
Mix with the clouds, that o’er the skies
Show their light forms, and disappear:
Or like the dust be tossed
By every sportive wind till all be lost!
—Æschylus.
If desire is sometimes the mother of invention, doubtless the wish to “mix with the clouds,” or “as smoke arise,” suggested to man his first means of aërial locomotion. Indeed this is openly avowed by Joseph Montgolfier. “Smoke rises in the chimney; why not encage this smoke, and have an available force.” But before describing his fundamental experiments of 1783, let us notice the less conspicuous ones, though not less philosophical, of his immediate predecessors in the development of aëronautic science.
It has been seen, that many years before 1783, inventors had clearly conceived the true principle of the balloon, and would be glad to avail themselves of an element of sufficiently low specific gravity for aërial flotation. The desired opportunity came when, in 1766, Henry Cavendish published his experiments, proving that hydrogen is many times lighter than air. Immediately after this, Dr. Black, the famous chemist and natural philosopher of Edinburgh, conceived the idea that a thin light vessel filled with hydrogen should be able to float and rise in the atmosphere, ideas that he conveyed to his friends and expressed in his lectures a year or two after the appearance of Cavendish’s publication. But he contented himself with merely pointing the way to an obviously practicable invention, leaving, as a university professor should, the development of the scientific idea to inventors and constructive engineers.
Intermediate between Dr. Black, the pure scientist, and the Montgolfier brothers manufacturers, came Tiberius Cavallo, an Italian philosopher living in England, who made the first small hydrogen balloons. In a note presented to the Royal Society of London, June 20, 1782, he relates experiments that seem to entitle him to all the credit of inventing the balloon except success on a practical scale. He made hydrogen soap bubbles which rose beautifully in the air, an experiment that has been repeated throughout the world in every chemical laboratory since his day. He made a variety of gum bubbles and varnish bubbles inflated with hydrogen; but curiously enough these failed to rise, though it is known that such bubbles can be made to float handsomely.[5] He inflated carefully prepared gold-beater skin and failed, though gold-beater skin balloons, both large and small, are now a marketable commodity. Finally he constructed paper balloons which he tried to float by use of hydrogen, but without success, though a year later the Montgolfier brothers easily made paper bags arise with hot air, and Professor Charles ascended in a large silk balloon inflated with hydrogen.
The cause of Cavallo’s interesting failures reveals itself in his own account of one of his pioneer experiments. In his History and Practice of Aërostation, he relates that he constructed, of fine Chinese paper, a cylindrical balloon having short conical ends and a calculated buoyancy of twenty-five grains, when properly inflated with hydrogen. This bag, carefully deflated of air by compression between the hands, he suspended above a large bottle connected with it by a glass tube, and supplied with materials for generating hydrogen; in this case a mixture of dilute sulphuric acid and iron filings. When the hydrogen was evolving quite rapidly, he expected to see the paper sac expand and fill out with proportionate speed; but to his surprise it remained perfectly flat, while the room filled with the strong and disagreeable odor of the “inflaminable air.” He then realized that the carefully made sac of paper, which could be so easily inflated with air, was very permeable to hydrogen, allowing it to escape instantly, as through porous cloth, or netting.
Cavallo desisted when the goal was within reach. His plans were practicable, but he abandoned them too readily. Why did he not varnish his balloon when it leaked? He could thus so easily have inaugurated the art of aërial navigation. But after salting the bird’s tail he let it escape.
Various accounts have been given of the steps by which the Montgolfiers were led to their invention of the balloon. They are said to have studied and discussed projects for aërial locomotion a decade before hitting upon their first successful device; at one time filling a paper bag with smoke ineffectually; again with steam, and again trying, but in vain, to employ hydrogen. The following apparently reliable account is given by a friend of the Montgolfiers, Baron Gernando, in his biographical notice of Joseph Montgolfier, having obtained the story from the inventor himself.
Joseph Montgolfier found himself at Abignon, and it was at the time when the combined armies held the siege of Gibraltar. Alone, in the chimney corner, dreaming, as usual, he was contemplating a sort of cut that represented the work of the siege; he grew impatient observing that one could not reach the body of the place either by land or sea. “But could not one arrive there through the air? Smoke rises in the chimney; why not store this smoke in such a manner as to form an available force?” His mind calculated instantly the weight of a given surface of paper, or taffeta; he constructed without delay his little balloon, and saw it rise from the floor, to the great surprise of his hostess, and with a peculiar joy. He wrote on the spot, to his brother then at Annonay: “Prepare immediately a supply of taffeta and cordage, and you shall see the most astonishing thing in the world.”
A quainter story is told by Brisson in his Dictionary of Physics. He says: “I can only repeat what the citizen Montgolfier himself told me, when he came to Paris to announce his discovery; that the citizeness Montgolfier having placed a skirt on an open-wicker basket, such as women use to dry linen, the skirt was lifted to the ceiling. It is from this fact that the citizens Montgolfier started.”
Whatever the preliminaries, the Montgolfier brothers finally made the experiment of holding a paper bag over a fire fed with wet straw and wool. It is doubtful whether they purposed to fill it with smoke, or with hot air or an electrical cloud. They knew that a cloud of some kind rises from such a fire, and they wanted to harness it. Their first balloon took fire and went up as smoke. But they were rich paper manufacturers, and soon had another balloon of 700 cubic feet capacity. This rose from the fire to a height of 1,000 feet, carrying no fuel with it. Thus two practical[6] men had made fire lift a paper sac; let the Academy explain how. The baby Aërostation was born.
How fortuitous the primal steps of science! Galvanism from the twitch of a frog’s leg; aërostation from the puff of a petticoat! There had been no year in thirty centuries when people could not easily have built a hot-air balloon. All the materials were available; only a little thought was wanting. A simple sketch sent to a Roman tailor, or tent-maker, could have furnished a woven bag competent to lift passengers from the heart of the Coliseum, to the wonder and delight of a hundred thousand spectators. Yet the genius that could design the Coliseum, or cover its vast enclosure with canvas, failed to think of the magic bag that would have enhanced so much the ingenious shows of a show-loving people. That device was an inspiration destined to a common Frenchman at no uncommon period of science. The hydrogen balloon arrived in the natural and logical order of scientific progression; but the hot-air bag might have presented itself at any time since the birth of weaving. It was a happy thought, like the ophthalmoscope, or jack-knife—quaint modern creations of constant use or comfort to mankind.
The public inauguration of aëronautics occurred on June 5, 1783, at Annonay, the home of the Montgolfier family, 36 miles from Lyons. The states of Vivarais being assembled at that place, were invited to witness the ascension. The Deputies and many spectators found in the public square an enormous bag which, with its frame, weighed 300 pounds, and would inflate to a ball 35 feet in diameter. When told that this huge mass would rise to the clouds they were astonished and incredulous. The Montgolfiers, however, lit a fire beneath and let the bag speak for itself. It gradually distended, assuming a beautiful form, and struggling to free itself from the men who were holding it. At a given signal it was released; it ascended rapidly, and in ten minutes attained a height of 6,000 feet. It drifted a mile and a half and sank gently to the ground.
Fig. 5.—Montgolfier’s Experimental Balloon.
When the French Academy learned of this event they desired to have an ascension in Paris, and at once started a public subscription to defray the expense of constructing and inflating a balloon. They placed the work in charge of the physicist Charles, after inviting the Montgolfiers to Paris, and finding they could not come immediately. Charles proved more than a substitute; he became a fertile inventor and a rival in the new field. Aided by the skill of the Robert brothers, he made a silk globe varnished with dissolved rubber, and filled it with hydrogen, which is many times lighter than hot air. The operation of filling occupied three days, consuming 500 pounds of sulphuric acid and half a ton of iron. The globe was 13 feet in diameter, and designated a “balloon,” or big ball. This had next to be moved from the place of filling, in the Place des Victoires, to the Champ de Mars, two miles distant, in order to have space enough to accommodate the increasing crowd of spectators. Accordingly, on the 26th it was conveyed thither, in the dead of night, preceded by lighted torches, surrounded by a cortege, and escorted by foot and horse guards. Impressive and weird, indeed, was this nocturnal caravan of troops and towering globe advancing slowly through the dark and silent streets. The astonished cab drivers knelt humbly, hat in hand, while the procession passed.
The ascent of this, the first hydrogen balloon, was a popular and a memorable event. The field was lined with troops. The curious spectators had thronged every thoroughfare and darkened every housetop. It was an all day festival, inaugurating a peculiarly French science, with French animation. The booming of cannon announced to all Paris the impending flight of the balloon. At five o’clock, in the presence of 50,000 spectators, and in a shower of rain, the balloon rose more than half a mile and entered the clouds. The people overwhelmed with surprise and enthusiasm, stood gazing upward, despite the rain, observing every maneuver till the vessel had ascended and faded from view.
Fig. 6.—Charles’ First Hydrogen Balloon.
The landing of this little balloon did not leave it in a condition to exhibit proudly to future generations. After drifting three quarters of an hour, it fell in a field near Gonesse, a village fifteen miles from the place of ascension, apparently ruptured from overdistention. The villagers flocked about it with curiosity and trepidation, ignorant of its nature, whether of bird kind or monster; and doubtful of its origin, whether natural or satanic. They fell upon it with flails and pitchforks. When struck it smelt strongly of sulphur, indicating a diabolic source. They finally hitched it to the tail of a horse which galloping away in terror, badly damaged it. Whether this destruction was wrought through fear or rustic hilarity, it induced the government of France to issue a notice to the public explaining the innocuous nature of a simple balloon.
In the meantime Joseph Montgolfier, having reached Paris, had constructed a waterproof linen balloon 46 feet in diameter and ornamented in oil colors, which was to be publicly launched at Versailles. On September 19, 1783, the king and queen, the court and a vast throng of people of every rank and age, assembled to witness the ascension. Montgolfier explained to them every detail, and finally lit the fire, about one o’clock. The great bag gradually expanded, rounding out in eleven minutes to a beautiful globular form, tugging upward with a force of seven hundred pounds. Beneath was suspended a wicker cage containing the first aërial passengers—a sheep, a rooster and a duck. The vessel rose majestically above the applauding multitude to a height of fourteen hundred feet, and drifted some two miles in eight minutes, descending gradually in the wood at Vaucresson. The animals were tipped out on landing; but, when found by two game-keepers, they were none the worse for their strange journey. The sheep was grazing and the cock crowing, says one report, while another relates that the sheep had trampled on the rooster and lamed him.
Stephen Montgolfier now wishing to send up human passengers, made a balloon of 100,000 cubic feet capacity. It was shaped like a full lemon pointing upward, with a cylindrical neck below, 16 feet in diameter. Around this neck was a wicker balcony three feet wide, to carry the aëronauts, bundles of straw for fuel, pails of water and sponges to extinguish incipient conflagrations, here and there in the balloon, during a journey. Through stokeholes in the side of the neck sheaves of straw could be forked to the grate suspended centrally below by radial chains. During inflation the base of the balloon rested on a platform, and its top was supported by a rope stretched between two poles. The vessel when completed, in a garden of the Faubourg St. Antoine, was 85 feet high by 48 feet across, and weighed 1,600 pounds. About its zone, painted in oil, were elegant decorations; portraits, cyphers of the king’s name, fleur-de-lis, with fancy borders below and above; while higher still, on the arching dome of the bag, were all the signs of the celestial zodiac.
The handsome vessel was now ready; but what daring captain should navigate her? King Louis proposed two prisoners who were under sentence of death, and had to be killed somehow. But the brave Pilâtre de Rozier protested indignantly: “Eh quoi! de vils criminels auraient les premiers la gloire de senlever dans les airs! Non, non, cela ne sera point.” He stirred up the city, and finally prevailed, through the entreaties of the Marquis d’Arlandes, who secured from the king permission to accompany his friend.
After some days of preliminary practice in maneuvering the tethered balloon, these gentlemen were ready for an aërial voyage. On November 21, 1783, the balloon was inflated in the garden of La Muette palace, and stocked with enough straw for an hour’s journey. When all was ready Pilâtre de Rozier and the Marquis d’Arlandes stepped with eager courage into the gallery taking opposite sides to ensure proper balance. At two o’clock they rose splendidly, amid the acclamations of a vast throng of spectators, and at the height of 280 feet, removing their hats, saluted the surprised multitude. Encountering a south blowing wind, they drifted five miles in some twenty minutes, and landed safely in a field. The apparatus was soon assembled on a cart and returned to the Faubourg St. Antoine, where it was originally constructed. The details of this first human voyage in a balloon are very interesting and well told in a letter written by the Marquis d’Arlande to a member of the French Academy.
Fig. 7.—Montgolfier’s Passenger Balloon.
“At this time M. Pilâtre said: ‘You do nothing, and we shall not mount.’ ‘Pardon me,’ I replied. I threw a truss of straw upon the fire, stirring it a little at the same time, and then quickly turned my face back again; but I could no longer see La Muette. Astonished, I gave a look to the direction of the river.... M. Pilâtre then said, ‘See, there is the river, and observe that we descend.’ ‘Well, then, my friend, let us increase the fire;’ and we worked away. But instead of crossing the river, as our direction seemed to indicate, which carried us over the house of the Invalides, we passed along the island of Cygnes, reëntered over the principal bed of the river, and advanced up it as far as the gate de la Conference. I said to my intrepid companion: ‘See, there is the river &c.’ I stirred the fire, and took with the fork a truss of straw, which from being too tight, did not take fire very easily. I lifted it and shook it in the middle of the flame. The next moment I felt as if I were lifted up from under the arms, and said to my companion, ‘Now we mount, &c.’ At the same time I heard a noise toward the top of the machine, as if it were going to burst; I looked, but did not see anything. However, as I was looking up, I felt a shock, which was the only one I experienced. The direction of the motion was from the upper part downwards. I said then: ‘What are you doing? Are you dancing?’ ‘I don’t stir,’ said he. ‘So much the better,’ I replied, ‘it is then a new current, which, I hope, will push us over the river.’ In fact, I turned myself in order to see where we were, and I found myself between l’École Militaire and les Invalides, beyond which place we had already gone about 2,500 feet. M. Pilâtre said at the same time: ‘We are on the plain.’ ‘Yes,’ said I, ‘and we advance.’ ‘Work on,’ said he. I then heard another noise in the machine, which appeared to be the effect of a rope breaking. This fresh admonition made me examine attentively the interior of our habitation. I saw that the part of the machine which was turned toward the south was full of round holes, many of which were of a considerable size. I then said: ‘We must descend,’ and at the same time I took the sponge and easily extinguished the fire, which was round some holes that I could reach; but leaning on the lower part of the linen, to observe whether it adhered firmly to the surrounding circle, I found that the linen was easily separated from it, on which I repeated that it was necessary to descend. My companion said: ‘We are over Paris.’ ‘Never mind that,’ said I, ‘but look if there appears any danger for you on your side—are you safe?’ He said: ‘Yes.’ I examined my side, and found that there was no danger to apprehend. Farther, I wetted with a sponge those cords which were within my reach. They all resisted, except two, which gave way. I then said: ‘We may pass over Paris.’ In doing this, we approached the tops of houses very sensibly; we increased the fire, and rose with the greatest ease. I looked below me, and perfectly discovered the Mission Étranger. It seemed as if we were going toward Saint-Sulpice, which I could perceive through the aperture of our machine. On rising a current of air made us leave this direction, and carried us toward the south. I saw on my left a sort of forest, which I took to be the Luxembourg; we passed over the Boulevard, and then I said: ‘Let us now descend.’ The fire was nearly extinguished; but the intrepid M. Pilâtre, who never loses his presence of mind, and who went forward, imagining that we were going against the mills that are between Petite Gentilly and the Boulevard, admonished me. I threw a bundle of straw on the fire, and shaking it in order to inflame it more easily, we rose, and a new current carried us a little toward our left. M. Rozier said again: ‘Take care of the mills’; but as I was looking through the aperture of the machine, I could observe more accurately that we could not meet with them, and said: ‘We are there.’ The moment after, I observed that we went over a piece of water, which I took for the river, but after landing, I recollected that it was the piece of water, &c. The moment we touched the ground, I raised myself up to the gallery and perceived the upper part of the machine to press very gently on my head, I pushed it back, and jumped out of the gallery, and on turning toward the machine, expected to find it distended, but was surprised to find it perfectly emptied and quite flattened, &c.”
While the foregoing experiment was in progress, plans were matured for the construction of a hydrogen balloon large enough to support two passengers and remain aloft many hours, without the need of carrying dangerous fuel. This type of balloon, called a Charlière, after its inventor, was destined largely to supersede the hot-air type, known as the Montgolfière, and indeed, to replace it entirely for free voyages of considerable endurance and for most power voyages. The construction after the plan of Professor Charles was delegated to two very intelligent mechanics, the Robert brothers who also had succeeded in dissolving caoutchouc, and thus producing a very superior balloon varnish. The project was first announced in the Journal de Paris of the 19th of November 1783. As usual in those days of public enthusiasm, a subscription was opened to defray the expenses of the experiment, estimated to cost about ten thousand francs.
Fig. 8.—Charles’ Passenger Balloon.
This balloon was a truly scientific creation, which advanced aërostation from tottering infancy almost to full prime. The bag was a sphere 27½ feet in diameter made of gores of varnished silk. A net covered the upper half and was fastened to a horizontal hoop girding the middle of the globe, and called the “equator.” From the equator depended ropes which supported, just below the spherical bag, a wicker boat measuring eight feet by four, covered with painted linen and beautifully ornamented. The balloon had at the bottom a silk neck 7 inches in diameter, to admit the gas during inflation, and at the top, a valve which could be opened by means of a cord in the boat to let out gas during a voyage, so as to lower the balloon, or to relieve excessive pressure. In the boat were carried sand ballast to regulate the height of ascension, a barometer to measure the elevation, anchor and rope for landing, a thermometer, notebook, provisions, and all the paraphernalia of a scientific voyage. Barring the fancy boat, this is almost a description of a good modern balloon.
The inflation and ascension occurred in the Garden of the Tuileries, where the limp bag was initially suspended from a rope stretched between two trees. For three days and nights the hydrogen, drawn from twenty barrels containing iron and dilute sulphuric acid, poured upward through the silken neck into the distending globe, which swelled in volume to 1,400 cubic feet. Finally on a beautiful day, the first of December 1783, the Tuileries and all the neighborhood were crowded with spectators. A numerous guard of soldiers, stationed about the apparatus and grounds, preserved order. The fashion and nobility of Paris were there, in ample splendor, attracted by the novelty and importance of the experiment, and the fame of the inventor. Shortly before two o’clock Professor Charles presented to his friend, Montgolfier, a pilot balloon six feet in diameter, saying, “It is your prerogative to blaze the way through the sky.” The pilot balloon was released, showing to everyone the direction of the aërial currents. Charles and Roberts stepped into the boat, seated themselves, and quickly rose into the sky. The multitude gazed in silent wonder. Presently they observed two pennants waving high above them, though the navigators were scarcely visible; whereupon they burst forth into wild enthusiasm and thunderous applause.
Immediately a cavalcade set out in hot pursuit of the venturesome sailors. It was the first chase after an air ship, and a most vigorous one. The balloon drifting northwestward at a speed of fifteen miles an hour, crossed the Seine, passed over several towns and villages, to the great astonishment of the inhabitants, and landed in a field near Nesle. Here it was securely held by friendly peasants, to await the advent of the official witnesses. Presently these arrived, drew up a certificate of descent and signed it. The Duke de Chartres, and the Duke de Fitz-James, who had followed less swiftly, now rode up and signed the formal document, to the great gratification of the aëronauts. The aërial journey had been a most delightful one, lasting about two hours and covering nearly thirty miles.
After receiving the felicitations of his friends, Charles determined to reascend, in order to obtain further scientific observations. Owing to leakage and loss of buoyancy, he must now leave behind his pleasant companion. He had proposed replacing with earth, or stones, a part of Mr. Robert’s weight, but, finding none at hand, he signaled the peasants to let go, whereupon he rose with unusual speed. The remainder of this first and very remarkable scientific voyage is well told by the navigator himself:
“In twenty minutes I was 1,500 fathoms high; out of sight of all terrestrial objects. I had taken the necessary precautions against the explosion of the globe, and prepared to make the observations which I had promised myself. In order to observe the barometer and thermometer, placed at the end of the car, without altering the center of gravity, I knelt down in the middle, stretching forward my body and one leg, holding my watch in my left hand, and my pen and the string of the valve in my right, waiting for the event. The globe, which, at my setting out, was rather flaccid, swelled insensibly. The air escaped in great quantities at the silken tube. I drew the valve from time to time, to give it two vents; and I continued to ascend, still losing air, which issued out hissing, and became visible, like a warm vapor in a cold atmosphere. The reason of this phenomenon is obvious. On earth, the thermometer was 47°, or 15° above freezing point; after ten minutes’ ascent it was only 21°, or 11° below. The inflammable air had not had time to recover the equilibrium of its temperature. Its elastic equilibrium being quicker than that of the heat, there must escape a greater quantity than that which the external dilatation of the air could determine by its least pressure. For myself, though exposed to the open air, I passed in ten minutes from the warmth of spring to the cold of winter; a sharp dry cold, but not too much to be borne. I declare that, in the first moment, I felt nothing disagreeable in the sudden change. When the barometer ceased to fall, I marked exactly 18 inches 10 lines (20-01 in. English), the mercury suffering no sensible oscillation. From this I deduce a height of 1,524 fathoms (3,100 yards), or thereabouts, till I can be more exact in my calculation. In a few minutes more, my fingers were benumbed by the cold, so that I could not hold my pen. I was now stationary as to the rising and falling, and moved only in an horizontal direction. I rose up in the middle of the car to contemplate the scene around me. At my setting out the sun was set on the valleys; he soon rose for me alone, who was the only luminous body in the horizon, and all the rest of nature in shade; he, however, presently disappeared, and I had the pleasure of seeing him set twice in the same day. I beheld, for a few seconds, the circumambient air and the vapors rising from the valleys and rivers. The clouds seemed to rise from the earth and collect one upon the other, still preserving their usual form, only their color was gray and monotonous from the want of light in the atmosphere. The moon alone enlightened them, and showed me that I was tacking about twice; and I observed certain currents that brought me back again. I had several sensible deviations; and observed, with surprise, the effects of the wind, and saw the streamers of my banners point upwards. This phenomenon was not the effect of the ascent or descent, for then I moved horizontally. At that instant I conceived, perhaps a little too hastily, the idea of being able to steer one’s course. In the midst of my transport I felt a violent pain in my right ear and jaw, which I ascribed to the dilatation of the air, in the cellular construction of those organs, as much as to the cold of the external air. I was in a waistcoat and bareheaded. I immediately put on a woolen cap, yet the pain did not go off but as I gradually descended. For seven or eight minutes I had ceased to ascend; the condensation of the internal inflammable air rather made me descend. I now recollected my promise to return in half an hour, and, pulling the string of the valve, I came down. The globe was now so much emptied, that it appeared only a half globe. I perceived a fine ploughed field near the wood of Tour du Lay, and hastened my descent. When I was between twenty or thirty fathoms from the earth I threw out hastily two or three pounds of ballast, and became for a moment stationary, till I descended gently in the field, about a league from the place whence I set out. The frequent deviations and turnings about make me imagine that the voyage was near three leagues, and I was gone about thirty-three minutes. Such is the certainty of the combinations of our aërostatic machine, that I might have kept in the air at least for twenty-four hours longer.”
Further interesting details of the first balloon experiments at Paris are furnished by Dr. Benjamin Franklin, then American Minister to France, in his letters written to Sir Joseph Banks, President of the Royal Society of London, and presented in [Appendix II] of this book. These quaint and substantial stories are well worth perusal as the expressions of a great diplomat and philosopher who, in the midst of social and political activities, found time for scientific correspondence with his friends in both hemispheres.
Aërial navigation was now become a practical art which should advance rapidly in popularity, in both Europe and America. Very soon ascensions were made everywhere, for private amusement and for public exhibitions. Not a few were made for scientific, for military and for topographical purposes; thus giving the art a utilitarian as well as a sporting feature. It will be interesting to note some of the more conspicuous ascensions, voyages and improvements made in passive balloons subsequently to the invention of Montgolfières and Charlières.
The largest hot-air balloon ever constructed, La Flesselle, was launched from the suburbs of the city of Lyons on January 19, 1784, just two months after the ascent of the first human passengers. It was also one of the most troublesome to assemble and keep in repair. Day by day, for more than a week, the balloon was inflated for the purpose of attaching the ropes to support the great gallery. But the wind blew dreadfully at times; rain and snow fell on the machine; frost and ice covered the huge bag; many rents ensued, demanding frequent repairs. On one occasion, when fed too freely with flame from straw sprinkled with alcohol, the monstrous ship rose so vigorously as to drag fifty men with it some distance along the ground. Finally on the 19th of January, when the weather moderated, the operators built small fires under the scaffold below the balloon, and thawed away the ice from the drenched and frozen bag. Then they stocked its gallery with straw and pitchforks, with fire extinguishers, and other provisions for the journey. The inflation beginning about noon, occupied but seventeen minutes. The balloon swelled out rapidly, with the roaring flames ascending inside, and at last stood forth huge and majestic before the admiring multitude—a towering thing of magic growth, 100 feet in diameter by 130 feet high.
The ascension of this gigantic vessel was immensely spectacular; but it was also most adventurous and foolhardy. The great bag, which at best was made of poor materials, was in bad repair after its frequent inflations. But of the six passengers in the gallery not one could be induced to remain behind to lessen the risk to the others. Their pilot, M. de Rozier, remonstrated with them; the proprietor M. C. Flesselle wished them to cast lots; but no one would abandon the journey. So, with fear and reluctance, the pilot ordered the mooring ropes to be cut. Just as the ascent began, a seventh passenger, M. Fontaine, sprang into the gallery and sailed aloft with the others. By vigorous stoking the aërial sailors urged their fiery vessel upward three thousand feet, whence, apparently without fear, they waved their hats to the vast throng below.
Fig. 9.—La Flesselle.
The spectators were now in a frenzy of excitement. For more than a week they had vacillated between hope and disappointment; but now they saw the huge ship soaring into the sky, perhaps on her way to destruction. They heard the blast of martial music and the booming of mortars. Then the accumulated emotion of the multitude burst forth. Exclamations of joy, shrieks of fear, thunders of applause resounded above the sea of people. Finally the balloon began to burst, a dangerous rent running vertically along her side. The machine descended with great rapidity, to the alarm of everyone. It is reported that not fewer than sixty thousand people ran to the place of landing, with the greatest apprehension for the lives of the travelers. But the adventurous men stepped forth from the gallery, after a fifteen minutes’ voyage, without hurt of any kind, save an insignificant scratch borne by Joseph Montgolfier, who on this occasion made his first and last ascension. This was also the first and last ascension of that gigantic fire balloon; for although it furnished a world of delirious emotion and excitement, the trouble of inflating the vessel was too great to be repeated.
The crossing of the English Channel by balloon had been contemplated many months by various adventurous spirits; and at length, on a fine day, the seventh of January, 1785, this feat was attempted by two intrepid men, the French aëronaut, M. Blanchard, and an American physician, Dr. Jeffries, who had graduated at Harvard in 1763, and was practicing medicine in England. Starting from the perpendicular cliff at Dover Castle, at one o’clock, they sailed in the direction of Calais, having with them only thirty pounds of sand ballast. This was too little for so long a voyage; but it would doubtless carry them a few miles, in the favorable breeze then blowing. To their surprise, the atmosphere seemed to grow lighter as they advanced over the water, letting them sink too freely. As they approached mid-channel they were compelled to discharge all their ballast in order to maintain their level. But the balloon still descended, seemingly attracted by the water. Then they ejected a parcel of books to gain a moment’s relief. When three-fourths across the Channel they sighted the French Coast, which now they yearned to see at closer range; for the balloon was contracting and sinking rapidly. They threw out from the boat everything available, wings, anchors, cords, provisions; yet they saw the vessel persistently approaching the sea. Finally they cast off part of their clothing, fastened themselves to the cords suspended from the balloon-ring, and prepared to cut away the boat. But presently approaching the coast near Calais, they began to rise; then ascended rapidly, soaring in a magnificent arch above the high grounds. At last they descended gradually above the forest of Guines, seized the branches of a tree to stop their flight, and at three o’clock were happily landed. It was a thrilling voyage of two hours, and made a profound impression at the time. As a mark of appreciation the King presented Blanchard a sum of 12,000 francs and a pension of 1,200 francs per year. The people erected a monument on the place of landing to commemorate this extraordinary voyage.
This splendid achievement incited two Frenchmen to attempt a counter voyage which ended disastrously. On June 15, 1785, Pilâtre de Rozier and M. Romain set out from Boulogne on a voyage from France to England, in a compound balloon composed of a hydrogen balloon forty feet in diameter, below which was suspended a fire balloon ten feet in diameter. They hoped by judicious stoking of the lower balloon to obviate the sinking tendency suffered by Blanchard and Jeffries. But the smaller globe proved a fatal auxiliary. Scarcely a quarter of an hour after launching, the whole apparatus was aflame at an altitude of 3,000 feet, and presently fell in charred and hideous fragments upon the seashore. M. Romain still showed some signs of life, but Pilâtre de Rozier was completely dead and all his bones were broken. They were the first martyrs in the cause of the new science. Poor De Rozier knew on starting that his apparatus was in bad condition, but he had received for the purpose a sum of money from a distinguished patron, and therefore felt obliged in honor to attempt the voyage. He was twenty-eight years old and engaged to be married to a young lady in the convent at Boulogne, who eight days after the catastrophe which robbed her of her fiancé, died brokenhearted and in convulsions.