William G. Krueger

“ The flight of a shoal of flying-fish as they shoot forth from the dark green wave in a glittering throng, gleaming brightly in the sunshine, is a charming sight. But these fish can scarcely be classed with the creatures of the air, because true flight, that is the manipulation of the wings, is lacking. They are mentioned because they represent, like the kite, the first step toward that true flight which all other creatures in the air possess. ”

“ In contemplating the boundless atmosphere, we perceive it to be tenanted by a multitude of creatures of varied form and size, who move and direct themselves with marvellous ease and skill. These beings, so different in their nature, form and construction—from [pg 24] the proud eagle to the "blood-thirsty" mosquito—resemble one another in the possession of three important fundamental principles which constitute the power of flight. These are—weight or gravity, surface or resistance of the atmosphere against it, and force or power of projection. ”

“ Again, higher up, or when clouds intervene, the sky, at all times darker when viewed from an elevation, seems almost black with the intensity of night; while, by contrast, the stars redoubled in their lustre, shine like sparks of the whitest silver, scattered upon the jetty dome around. Nothing can exceed this density of night. Not a single object of terrestrial nature can [pg 15] anywhere be distinguished, and an unfathomable abyss of "darkness visible" encompasses one on every side. ”

“ The sparrow weighs about ten times less than the pigeon, and has twice as much surface in proportion. The Australian crane—one of the heaviest birds, it weighs over twenty pounds, or almost three million times as much as the gnat—possesses the least surface—not quite ten square feet, or one hundred and twenty times less than that insignificant but formidable animal. Yet its flight is, gliding softly on the air, without effort or fatigue, with but little exertion, the longest maintained, and it can, with few exceptions, elevate itself the highest. ”

“ The problem of artificial flight is of such great importance to civilization; so interesting and fascinating, not only to the student, but to every one; and it allows us to indulge in such a wide field for speculation as to the great changes which will be wrought by the practical solution of it in the social, political and commercial world, that I must beg of you to consider only my good intentions in appearing before you, and pardon my shortcomings as a lecturer. ”

“ Atmospheric pressure, exerting nearly 30,000 pounds upon a human being of full growth, has much to do with the mechanical functions of life. At a moderate elevation, one-tenth of this weight can be relieved, and at greater hights, even one-third, as balloon experiments have sufficiently proven. This pressure, then, diminishing upon the muscular system, allows it to expand. The lungs at once become more voluminous and breathing purer air; the freedom with which all the circulating fluids of the system are allowed to act in the rare atmosphere, intensely quicken the animal and mental faculties ”

“ As for the objection, that the fury of the wind will [pg 37] hinder artificial flight, it is refuted by observing that even a hurricane, which, traveling over eighty miles an hour, occurs but rarely, does hardly prevent the flight of fast birds, and still less would that of a compact and solid flying machine, because of its greater weight and momentum. And even if an occasional storm should be dangerous, the machine, by its greater swiftness, could be turned above, below or sideways, out of the path of destruction, or it need not travel at such rare times. ”

“ It must be convincing, therefore, that it is possible for man to apply the laws of flight to industrial purposes in the same manner as he has been able, in these days, to apply all the other grand physical laws that he has taken the trouble to study and fathom. The law of surface and force reigns in the most absolute and exact manner over all flying animals. ”

“ Modern engineers have created machines which execute more difficult and various operations [pg 35] than animate beings are capable of; yet it is always from nature first that man has to draw his inspirations.
Of the different functions of animal mechanism, that of locomotion is certainly one of the most important and interesting; and as we have brought this art on land and water, by successfully imitating the natural movements of walking and swimming, to quite a high state of perfection, the next great problem, equally possible, because flight is a natural movement, remains to be solved. ”

“ By giving the machine an upward angle, the planes strike continually upon new layers of air, and so cause a rise, like a kite pushed from behind. The whole structure had about thirty-six square feet of surface, and weighed, including the steam engine, which exerted nearly one-half horse power, under 12 pounds. It proved conclusively that, while the inclined plane, in a practical and different form, is necessary for ærostation, the secret of solving the problem lays far more in the mechanical application of certain laws governing the art of flight, than in enormous power. ”

“ If the air passenger suffers from gout, rheumatism, or is susceptible to sea-sickness, he will experience no inconvenience, because there is no jogging, no rumbling over cobble-stones or broken rails, or riding on a heavy sea; he will feel no motion at whatever hight he may be, but will glide voluptuously—without perception almost—like a summer cloud through the vast ocean of the ærial fluid. ”

“ What extra strength the animal possesses has to be used in pursuit or escape, from the powerful eagle to the minutest insect; they must be prepared to exert at a given moment all the strength that nature has given to them in store.
Their strength is no greater than that of fishes or quadrupeds; all possess surplus power greatly above the need of their average use, and the strength exhibited therefore by flying creatures shows only that but a small portion of it is used for lifting and propelling purposes. ”

“ Flying will become a business, a trade, and the advantages derived from it for industrial purposes will be wonderfully great. New channels of employment will be opened to thousands, yes, millions of starving fellow-beings. A new era will be inaugurated in history; and great as has been the destiny of our race, it will be quite outlustred by the grandeur and magnitude of coming events.
Traveling at a speed of over one hundred miles an hour, distance will become comparatively annihilated. ”

“ The kite is maintained in the air by two opposing forces: the impelling power of the wind—lifting it by striking against it at an angle, and the restraining powers of the string—motive-force and gravitation combined; so that in the kite, above all, we possess in a crude form, the three principles requisite for artificial flight: the plain, weight and propelling force. By improving upon the kite, therefore, we will arrive at the practical solution of the problem of artificial flight. ”

“ It is not creditable to the present age that the problem [pg 19] of ærial navigation has not been solved. But one of the causes has undoubtedly been the discovery of the balloon, which has retarded this science for nearly a century by misleading men's minds, and causing them to look for a solution of the problem by the aid of a machine lighter than air, and which has no analogue in nature.
Weight is one of three essential factors in flight, for a light body cannot be propelled through a heavier one. ”

“ The half obscured sun shedding his mellow light upon the picture, gives it a rich and dazzling lustre. Reverence for the work of nature, the solemn stillness, an admiration indescribable, all combined, seem to make a sound of praise. ”

“ Hence, all flying animals are many hundred times heavier than air, and the heaviest are generally the best flyers, yet require the least amount of surface and force in proportion.
The sympathy existing between weight and power is very great. Weight acts in flight upon the oblique surfaces of the wings in conjunction with the power expended, and thereby husbanding the latter immensely. ”

“ The machine being under perfect control, can be made to travel very slow when towards the point of destination, and may be stopped at any hight to remain stationary or leisurely descend. And lastly, speed appears greatly diminished when the object is viewed from a distance, as we can observe on a railroad train. A telegraph pole standing near the track will flit by like a flash of lightning, so to speak; but if any considerable distance off, it disappears very slow. But when an object is followed by the eye from a considerable elevation, this fact is still more striking. ”

“ When the novelty and excitement of this style of travel will have subsided, we may take the next step in ærostation by carrying a much greater number of passengers and heavier freight; not in a single machine, but by making two or more to support inclined planes of certain construction between them. These planes, in swift horizontal flight, could be made to carry, in suitable cars underneath, much more than their own weight, because the power of support which the air affords to inclined planes at a great speed is simply enormous, amounting to 50 ℔s. ”

“ Weight acts on flying creatures in a similar manner as we see it in the clock, where weight is the moving power, and the pendulum merely regulates its movements.
Of course, the belief of many, that birds have large air cells in their interior, that those cavities contain heated air, and that this heated air in some mysterious manner contributes to, if it does not actually produce, flight, falls to the ground upon the least reflection. ”

“ These planes were made to strike the air at a given angle, instead of continually changing to suit the elastic medium, and in which respect the ordinary kite is a better flying machine. If not driven with great velocity, such a machine can not support itself in the atmosphere; besides, on account of its great surface exposed, a strong wind can easily capsize it; while natural wings, on the contrary, present small flying surfaces, and their great speed converts the space through which they are driven, into a solid basis for support. ”

“ Therefore, bodies in the air are light or heavy in proportion to their surfaces, and the heaviest may become light by an alteration of form. For successful flight, then, a just proportion of surface and weight is necessary; because, as stated, the air being elastic, its resistance is much more effectual with light bodies than heavy ones; and this proportion is such that the extent of surface is always in an inverse ratio to the weight of the winged animal. ”

“ The fish first acquires initial velocity by a preliminary rush through the water, when it throws itself suddenly into the air, and, at the same moment, spreads out, kite-like, at a slight inclination upwards, its extraordinarily large pectoral fins. It keeps up the great speed until its momentum is exhausted, when the same performance is repeated.
[pg 34] The fact in favor of mechanical flight is certainly incontrovertible that less surface and less power is required and flight maintained the longest, in proportion to heavier bodies. ”

“ Such a machine, although possessing much less surface than parachutes generally do, is in the form of inclined planes of proper construction, fully sufficient for man to slide down safely through the air, without exertion, from an elevation at least ten times the vertical distance, that is, from the top of the Palace Hotel to the foot of Baldwin's.
As to the force required, although impossible to give datas, the law of decrease with greater weight reigns absolute here also. Man's muscular power for tolerably swift horizontal flight is far greater than necessary ”

“ A swallow, one of the very best flyers, lifts itself with difficulty from the ground. An eagle, particularly after eating, has to run some distance flapping its wings vigorously before it can rise. An insect, possessing considerable spring-power in its limbs, always takes a good jump at the moment its wings are spread out for elevation, at an upward angle forward. With similar contrivances for the purpose must a practical flying machine be provided. ”

“ Nature has wisely established a compensation to make amends for the diminutiveness of organs by rapidity of movement, and has, consequently, furnished the animal with the necessary power to produce this rapidity. ”

“ The great common characteristic of the different winged beings are the same throughout all the modifications of detail. These are, as stated, weight, extension of surface, and the mechanical application of the propelling force; so that the animal is a gliding plane, part of which is fixed and the other moveable, and the whole being maintained in stable equilibrium by the weight of the body, placed a little below the plane of suspension. ”

“ Borelli estimated the power of a three pound bird to be over one hundred and thirty horses relatively. But, Navier, more reasonably, calculated a force of five horses sufficient for the flight of a pigeon. Coulomb, again, offset this "great liberality" by demonstrating that the surface to support a man must be two miles long and two hundred feet wide, with the power of a "Corliss engine" to propel such a "fifty acre ranch."
Now, facts prove that man can, without danger, descend from an high elevation under a surface of much less than fifteen feet diameter ”