Part 3

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.

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. It does not stop here. Nature, whose laws are general and universal, has not created this one only for the restricted compass of the winged animate beings. The law which sustains on the water the leaf and the straw is the same for the gigantic Great Eastern; and the mechanical law of the forces which drives the wheelbarrow also conducts on its iron line the locomotive and its endless train.

XVII.--MECHANICAL PRACTICABILITY OF ARTIFICIAL FLIGHT.

Living beings have been, in every age, compared to machines, but it is only in the present day that the bearing and justice of this comparison are fully comprehensible. Modern engineers have created machines which execute more difficult and various operations 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.

Of course, as different as the wheel of the locomotive is from the limb of the quadruped, and the screw of a steamship from the fin of a fish, so will the coming flying machine differ from the construction of bird, bat or insect.

Walking, swimming and flying are modifications of, and merging into, each other by insensible gradations; and the modifications, resulting therefrom, are necessitated by the amount of support afforded on, and in the different mediums--earth, water, air. Although flight is, indisputably, the finest of the different animal movements, yet it does not essentially differ from the other two, as the material and forces employed are literally the same as those in walking and swimming.

Flight is, therefore, a purely mechanical problem, and in compliance with the law of decrease, as stated before, the surface requisite to transport bodies in the air, is found to be about one-half, proportionately, to twelve times the weight.

Applying this observation to an apparatus of, say 200 [lb]s., we find that the surface of a bird of 18 [lb]s.--about one-twelfth of said 200 [lb]s.--to be 10 square feet; multiplying this by twelve, its weight, we have 120 square feet of surface, and of which one-half accordingly, 60 square feet, is enough for the support of 200 pounds. 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; and, with properly constructed contrivances, he will be able to travel, at an incline upwards of one in thirty, at least twenty miles an hour, by manual power alone. A carrier pigeon flies, for a short time, at the rate of one hundred miles an hour, and some birds much faster. But in employing any of the many excellent motive powers at command now, and with larger machines, we will be able to surpass the swiftest birds.

As for the objection, that the fury of the wind will 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. Besides, the effect of the storm upon a body within its own medium is insignificant to what it is when that body offers resistance by being attached to another medium, as ships on the water, or houses and fences on land.

XVIII.--FLYING MACHINES OF THE PRESENT, THEIR DEFECTS.

When it was found that no marked improvements could be made in balloons, the more advanced thinkers, turning their attention in an opposite direction, commenced to justly regard the winged being as the true model for flying machines; and experiments are now being made, in different parts of the world, of which all go to prove that "_flight is far more a question of mechanical adaptation, construction and manipulation, than of enormous power_," which, of course, in any experiment, must prove unavailable, if improperly applied. Some of the motive engines, lately exhibited in England, produced such remarkable power as certainly no bird possesses. One of four-horse power weighed 40 pounds, and occupied but a few cubic feet; another of 13 pounds exerted over one-horse power; and, at some experiments in France last year, a steam engine of two and a half horse power weighed 80 [lb]s.; and, being applied to a machine with two vertical screw propellers of 12 ft. diameter each, it raised 120 [lb]s. of the whole weight of 160 [lb]s.

But, as far as known, these different motive powers have been employed so far only to elevate and propel machines by vertical fan-like contrivances--helicopterics or by æroplanes, pushed forward and upward by screw propellers; either quite as irrational as ballooning, because the rigid plane, wedged forward and upward at a given angle, in a straight line, or in a circle, does not embody the principles carried out in nature. Hence, the several advocates of the æroplane and helicopteric have met with but indifferent success.

Perhaps the best representative model of a flying machine on the principles of inclined planes, was that of Mr. Stringfellow, exhibited in London, in 1868, and which occasionally could rise. It had three æroplanes, superimposed as advocated by Wenham, the frames of which were made of light wood, with cloth drawn over it tightly, like rigid kites, fixed parallel one above the other, with a tail attached to the middle one. It had a small box underneath for the motive power, and a light screw propeller behind for pushing it forward. 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.

These kite-form machines did not succeed, in spite of their great motive power and lightness, because the supporting planes were not active and flexible, but presented passive or dead surfaces, without power to accommodate themselves to altered circumstances. 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. This arrangement enables wings to seize and utilize the air, and renders them superior to the adverse currents, not of their forming. In this respect they entirely differ from balloons, and all forms of fixed æroplanes.

The different small helicopteric models, relying entirely on the aid of the screw, made from time to time, were also lacking, as stated before, in some of the true principles of flight; although some of these models could not only rise, but also carry a certain amount of freight, as was shown by the delicately constructed clockwork models of M. Nadar, a prominent French scientist, and others. One remarkable model, exhibited some years ago, was that of M. Phillips. It was made entirely of metal, weighed two pounds, had four two-bladed fans inclined to the horizon at an angle of twenty degrees, and made to revolve in opposite directions with immense energy. The motive power employed was obtained from the combustion of charcoal, nitre and gypsum, the products of combustion mixing with water in the boiler and forming gas-charged steam, which was delivered at a high pressure from the extremities of the arms of the fans, on the principle discovered by Hero, of Alexandria.

The production of flight by artificial wings is the most ancient method proposed, and will, undoubtedly, in a greatly modified form, and in combination with other contrivances, solve the problem; but to exactly imitate natural wings will be found as impossible as the production by the other different methods proposed so far.

Of the more recent attempts at the solution of the problem by means of artificial wings, worked by steam power, the perhaps most determined was that of Mr. Kauffman, of Glasgow. The machine had superimposed æroplanes, similar to those used by Stringfellow. The two wings were of great length, narrow, pointed towards the end, and were made to flap up and down somewhat like the wings of a bird. The model exhibited weighed, complete, 42 [lb]s., but the dimensions for a large machine were to be: length, about 30 ft.; hight, 5 ft.; width, 6 ft.; length of each wing, 60 ft.; surface of each, 400 ft.; total weight of machine, 8000 [lb]s.; nominal power, 120 horses; intended speed, 60 miles per hour; with water supply for five hours and oil as fuel for ten hours. Besides, a pendule, weighing 85 [lb]s., and 40 ft. in length, was attached, which could, telescope-like, be drawn up when necessary. The model was made exactly, to show the inventor's theory, and to ascertain if the connection to the wings could be made strong enough to withstand the violent twisting and bending strains to which they were exposed. When steam at a pressure of over 150 [lb]s. was turned on, the wings made a short series of furious flaps and broke. The experiment failed, because, to exactly imitate the movements of the long and delicate wings of fast-flying birds on a large scale, is impossible; the leverage to flap up and down 60 ft. long wings being simply enormous beyond computation, and no material can be found strong enough to withstand it.

Another machine, the propulsion of which was also to be effected by means of artificial wings, was exhibited some years ago in England. It differed entirely from the other in this respect, that it was very light, weighing scarcely 30 [lb]s., and was intended for a man to fly by his own muscular power. It had about 70 square feet of surface, two short wings, and the ribs were made of paragon wire, such as is used in umbrellas, and covered with silk. By a preliminary quick run, the inventor could take short, jump-like flights of more than 100 feet; but this machine was also in a very crude state of perfection.

These different practical experiments, although more or less unsuccessful, and others similar, but of which many models were far more ingenious than practical, have at least established the certain prospect and certainty of an early solution of the problem. And were it not that but very few, comparatively, of the great number of theories, which have been proposed from time to time for the accomplishment of this great object, have been submitted to anything resembling even the remotest approach to practical tests, and that the lack of means is generally the insurmountable barrier in experimenting, ærial navigation would to-day be an established fact.

XIX.--THE PRACTICAL FLYING SHIP OF THE NEAR FUTURE.

Possessing then, all the datas possible on the subject, it is, perhaps, not so very difficult as is generally supposed, to arrive at a satisfactory result; and, like other great inventions before, the coming air ship will also be a rather simple affair. While it will not likely possess such prodigious weight as 8000 to 10,000 pounds, with a hundred and twenty horse-power steam engine--sufficient almost for a man of war, it will neither be as light as a feather, comparatively, but hold the golden middle.

The inclined planes, in a greatly modified form, will by no means be discarded, as in fact no flying machine could be built otherwise. But, as stated before, this is only one principle long recognized, the A B C, so to speak, towards the solution of the problem. These planes, in wedging forward, for certain reasons, should be _elastic_, in some manner, and which has not been attempted by any inventor yet. The frames and covering of all models, built so far, have been rigid and immoveable, and yet, even with these great defects, partial success has been obtained already.

The fan or screw never will be used as the _only_ means in propelling, but will be very effective in doing service as a part of the whole, with other contrivances in driving and guiding. But their form and style must be considerably different from anything known at present.

A modified and peculiar form and style of wings, as mentioned here before, must also be employed in combination with the planes and fans, to serve the double purpose of driving and lifting. By the manipulation of these wings the accumulating and compressed air is thrown underneath the machine, thereby urging the same in a forward and upward direction, and by which the planes in front are made to continually rise upon new layers of the elastic medium, like a kite when the boy runs forward.

The planes must be fixed in such a manner that they can be set at different angles with the horizon, in order that the machine may rise sooner when the angle is greatest, because of the greater resistance of the air against a larger surface exposed; and to glide through the atmosphere swifter, after elevation has been attained, when the angle of the planes is most acute, thereby offering the least amount of surface to the horizontally opposing air. No flying creature rises in the air vertically, but ascends at an incline.

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. It should, in combination with a certain amount of spring power, to enable it to rise with greater ease at the final moment, and also to reduce the shock in alighting to a minimum, have wheels to run over the ground, until sufficient force and momentum has been attained to launch it into the boundless realms of space.

To be thoroughly practical, the machine must be under perfect control, and be made to descend upon any spot desired with absolute safety and ease. This can be accomplished by the combined effort of the propellors and wings. By exerting the power of these contrivances in opposite directions the disturbed atmosphere is thrown in volumes underneath the machine, which, on account of its similarity to a parachute, although of a greatly different form, can be made to descend vertically and very slow.

The doubt expressed by many, that the guidance of an air ship is possible, is easily refuted. All bodies, possessing the propelling force within them, can guide themselves in an elastic medium. Of this we have millions of examples before us in all flying creatures.

Finally, a practical shape and proper size and weight will form one of the most essential elements in a successful flying machine, and which has been disregarded more or less so far. Of course, it is impossible to calculate already, before an actual machine has been built and datas can be fixed, the limits of these factors in the average ærial structure. My impressions are, that the weight of a single carriage will be from 400 to 500 lbs., inclusive; a motive force of 3 to 5 horse power. It will have a total length of from forty to fifty feet, by about the same in width, from tip to tip; and a surface of from 500 to 600 square feet will be more than sufficient to sustain a total weight of 1000 lbs.; for such a machine will be capable to carry from three to four persons, or its equivalent weight of express matter, letters, newspapers, and other light freight. Of course, free mail facilities for our wise solons will, perhaps, unfortunately have to be barred out.

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 [lb]s. per square ft. in a pressure of 100 miles per hour. For this purpose, the manner of placing these æroplanes one above the other, as proposed by Mr. Wenham many years ago, would be practical to some extent.

The great swiftness with which these machines are expected to travel, seems at first to rouse fear in us to trust our more or less valuable lives into such a wonderful structure; and it possibly staggers our belief that such great speed can be performed with any degree of safety to brittle bone and breathing valve. But all these objections are easily refuted. The ærial traveler sits securely inside the strong machine, in no danger of catching a cold from the strong air-current rushing by, very much like the passenger in a railroad car; and if of an inquisitive turn of mind for the beauty of the surrounding panorama, he has suitable windows for observation. 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.

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. The eye can command at a glance almost hundreds of miles of country, and a city can be seen at a distance of at least fifty miles in advance, giving the æronaut ample time for preparing a descent, if so desired. Of course, he must be well acquainted with landmarks, to know what part of country he is in; but this knowledge will be acquired much easier than water navigation.

Such about will be the coming flying-machine of the near future. The natural elements, so far from presenting barriers and obstacles, as they do to a great extent on land and ocean navigation, seem to be peculiarly inviting to ærostation.

Previous to nearly every great discovery, difficulties have been thought to exist which its completion dissolved. In the days of stage-coaching, the expectations held out by those interested in steam transport were considered, even by most competent and intelligent men, as wholly chimerical; yet the locomotive far surpasses the race-horse in speed and endurance. When practice proved and datas could be fixed, that smooth tires met all the requirements on railroads--in place of cogwheels to gear into racks--how easy all calculations on adhesive force and friction then became. So with flight.

XX.--WHAT THE CHANGES FOR THE BETTER WILL BE.

It is impossible to overestimate the benefits which will accrue to mankind from such a creation. Flying will become a studied art, an amusement, an accomplishment, and inconvenience from sultry heat, or freezing cold, or deadly epidemics will no longer be suffered. 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. Cutting through the air from San Francisco to New York, for instance, in twenty-four hours, at one-sixth in cost and time; far safer, because of no irregulations nor obstructions of road, no snow-blockades or unnecessary delays; far cheaper, because of no great expense for outfit or maintenance, the ærial carriage will soon become the great means of travel throughout the world.

The vast uninhabited but productive regions of this globe will be populated from overcrowded and impoverished communities, because of the extraordinary cheap, safe, and rapid travel by flying machines. New life will again be imparted to enterprise, speculation and labor; and lands will be cultivated and great cities be built in regions where the foot of human being has not trod for ages.

The Andes and Rocky Mountains will become as familiar to us as the hills of our own city; and mining and other discoveries will follow each other with wonderful rapidity. The vexing and expensive explorations in the interiors of Africa and Australia, and towards the North Pole, will soon be brought to a speedy and satisfactory conclusion; and some of the wildest dreams of men be realized.

XXI.--CONCLUDING REMARKS.