Every-day Science: Volume 7. The Conquest of Time and Space

by Henry Smith Williams; Edward Huntington Williams

That such a fabulous tale could gain credence is explained by the prevailing belief in the powers of the astrologers and sorcerers at that time. People who could seriously believe that an alchemist could create gold and prolong life and youth indefinitely, would find nothing startling in the announcement that he could also perform the relatively simple feat of flying—a thing that birds and bats accomplish with such obvious facility. And nothing is more certain than that attempts at aerial flight have been made at various times since the beginning of history.

As with almost everything else in the matter of modern scientific advancement, the mysterious writings of the monk, Roger Bacon, are supposed to contain passages to show that the worthy friar had an inkling of the secret of air navigation. But he himself admits that he had only a theoretical knowledge of the subject, and had never seen a flying-machine of any kind in actual flight.

Much more definite and tangible are the designs of possible flying-machines still extant in the sketch-book of Leonardo da Vinci, made in the fifteenth century. From Leonardo's sketches it appears that the artist had conceived the idea of constructing jointed wings to be worked with strings and pulleys, the motive power to be that of a man's arms and legs. It appears also that later he had very definite ideas as to the possibilities of an aerial screw, and he is believed to have constructed one of these screws made on the same general plan as that of the ordinary type of windmill in use at that time. But nothing of practical importance came of any of Leonardo's experiments.

It is probable that his abandonment of the project of flying by means of wings worked by muscular force was due to the discovery that the strength of the muscles of even the strongest man was relatively slight as compared with the corresponding muscle of birds. Leonardo was peculiarly capable of discerning this discrepancy in strength, since he himself was one of the strongest men of his time. It is said that he could bend and straighten horseshoes with his hands. But in his experiments with the aerial screw he probably discovered very soon that even such muscular force as he was capable of exerting was entirely inadequate; and there being no other mode of producing power at that time, the idea of aerial navigation by this means was also abandoned.

About this time some imaginative persons, realizing the possibilities of muscular development when begun in childhood and persistently practiced, attempted the development of a race of men whose abnormally strong pectoral muscles would enable them to use artificial wings for flying. For this purpose a certain number of young boys were selected and constantly drilled in exercises of flapping the arms, to which broad sails were attached. These attempts were persisted in for several years, and it is said that some of these boys became so expert that by skipping along the surface of the ground and vigorously flapping their wing-attachments, they could travel at incredible speed, although never able actually to rise from the ground.

In 1678, a Frenchman named Besnier invented a flying-machine that is credited with being more successful than any hitherto attempted. His machine consisted of two bars of wood which were so hinged to a man's shoulders that they could be worked up and down by movements of the hands and feet. At the ends of these two bars were muslin wings made like shutters, so arranged that they were opened by a downward stroke and closed automatically by a reverse motion. The general appearance presented by these wings was that of four book-covers fastened by their backs to the ends of the bars, opening and closing alternately as the bars were worked up and down.

The inventor began his experiments in a modest way. His first attempt at flight was by jumping from a chair; next he tried a table; and finally, emboldened by his success, he made flights from window-sills and even house-tops. On one occasion he is said to have sailed from his attic window over the roof of a neighboring cottage, alighting, without injury, some distance beyond. It was even rumored at one time that he would try to fly across the Seine, but if such a feat was ever contemplated, it was never attempted.

Half a century later, however, the Marquis de Bacqueville actually made such an attempt with a machine somewhat similar to that of Besnier. The marquis had practiced in private with his machine with such encouraging results that he felt confident the feat was not an impossible one—in fact, that he was sure of accomplishing it. He therefore announced publicly that at a certain time the attempt would be made, and on the appointed day an immense crowd of people gathered on the banks of the river to witness the spectacle. Starting from a building some little distance away from the stream, the marquis made good progress at first, but just as he reached the river-bank his machine collapsed and he was tumbled out, alighting on a barge moored at the edge of the stream. Fortunately, the only injury he sustained was a broken leg; but this single attempt seems to have satisfied his aeronautic ambitions.

Until this time all attempts made at aerial flight had been those in imitation of birds; but during the early part of the eighteenth century the idea of the balloon was developed. This was the result of the numerous important discoveries made about that time as to the qualities of the atmosphere, and also several other "airs," as gases were called, such as their expansion and contraction under different conditions of temperature.

In 1766 the English philosopher, Henry Cavendish, discovered that hydrogen gas has only about one-seventh the weight of an equal bulk of air, this scientific discovery pointing naturally to balloon construction, since obviously if such a light gas were confined in a suitable receptacle, the device would rise to a certain height through the heavier atmosphere, as a cork rises through water. At the same time the experiments of the chemist, Dr. Joseph Black, and those of his younger contemporary, Doctor Priestly, were directed along the same lines, all of them pointing to the possibility of constructing an aerostat with buoyancy and lifting-power, and Priestly's Experiments Relating to the Different Kinds of Air is said to have been directly responsible for stimulating the efforts of Stephen and Joseph Montgolfier, the French paper manufacturers, who finally invented and sent up the first balloon.