Francis A. Collins

“ The feats which the world has watched with such breathless interest at aviation meets at Rheims, Pau, or Los Angeles are reproduced in miniature in these boys’ contests without loss of enthusiasm. The weeks or months of preparation in scores of little workshops are now put to an actual test. The model air-ship, which has cost so many anxious and delightful hours in the building, is to spread its wings with scores of similar air-craft. The superiority of the monoplane or biplane forms is to be tested without fear or favor. ”

“ The flying machine which will navigate successfully in a perfectly quiet atmosphere may be unseaworthy, or rather, unairworthy, when a wind springs up, or the shifting of the wind may spoil all the air pilot’s plans. To add to his troubles, the aviator must move among air currents which change and change again in a moment’s time. As we study the difficulties of air navigation we will appreciate, more than ever, the wonderful patience, skill, and daring of the successful aviators.
The action of the air currents had first to be carefully studied before flight became possible. ”

“ Seen high aloft, with wings outspread, the monoplanes look like great eagles as, gracefully, but very noisily, they rise and fall in long, sweeping curves. The monoplane being a much lighter machine and less complicated is therefore cheaper to build than any multiplane model. Several of the successful models ride the air very steadily and have proven themselves capable of making long and difficult air journeys. ”

“ The rubber is so light that it adds little to the weight of the craft. The motor is of course a makeshift and at best only serves to keep the propeller in motion for a fraction of a minute. Experiments have been made in driving the propeller with compressed air, which is carried in an aluminium rod fastened beneath the planes. But the force of thousands of youthful inventive geniuses is certain to bring forth some new motive power.
It is characteristic of the American boy that our young aviators should feel themselves disgraced to fly a model not of their own make. ”

“ There is much beautiful scenery, high mountain peaks, deep valleys, and level plains formed by these ever shifting air currents through which the aviator must steer his course blindly as best he may. A great bank of whirling clouds driven before the wind shows how rough and tumbling a sea he must navigate.
The air being a much thinner medium [Pg 19] than water is, of course, far more unstable and baffling. Its supporting power is not only very small but constantly varies. ”

“ Each young aviator winds up his craft, adjusts the power with his own hands, and sets the rudder for the flight.
The miniature air-craft must act in flight exactly the same as the great working air-craft which carry men aloft. A toy air-ship must make its flight in a horizontal position, and if it turns over in flight, even though it flies farther and faster than any other, it is disqualified. ”

“ EVERY one knows, of course, that the box-kite flies better than a plane surface, and many believe that the box or cellular type of aëroplane has a similar advantage over the monoplane. The enclosed end keeps the air from slipping off the edges of the plane, and makes for stability. There is all the difference in the world, or rather in the air, between an actual flight and the movement of a model aëroplane. The aviator, by flexing his planes, and adjusting his rudders fore and aft, may balance his craft to suit the air currents. ”

“ The exact position of the weight can only be determined by experiment. The simplest way is to wire a nail or a piece of metal to the edge of the frame. If your glider does not balance perfectly, which is likely to be the case, this fault can be largely remedied by weighting it. The tendency of the glider is likely to be upward, and the weight serves to keep it on an even keel. When your model glides steadily through the air, without rolling or pitching, you have constructed a well-balanced frame. It will then be time to take up the problem of propulsion. ”

“ The question of rudders or guiding planes is very important. It is too much to expect of even the best model that it will fly in an unswerving line. Any simple vertical plane which may be turned from side to side and held in position will act as a rudder. There is great difference of opinion as to the proper size and position [Pg 73] of these guiding surfaces. It is argued by some aviators that the rudder should be placed above the plane, where the air is undisturbed, while others believe that the partial vacuum created above the wings in flight makes the propeller ineffective. ”

“ The great problem in warfare of patrolling the frontier of a country against possible invasion seems to be solved by the dirigible. Two or three men aboard a dirigible, with a traveling radius of several hundred miles, could do more effective work than several thousand men scattered along the frontier line.
For dispatch work the flying machine is expected to be indispensable in warfare. The bearer of dispatches has always played an important part in war. His work is often of the most perilous nature, and his journeys, at best, are slow and uncertain. ”

“ The operator moves a lever; the right wing rises and the machine swings about to the left. You make a very short turn, yet you do not feel the sensation of being thrown from your seat, so often experienced in automobile and railway travel. You find yourself facing toward the point from which you started. The objects on the ground seem to be moving at much higher speed, though you perceive no change in the pressure of wind in your face. ”

“ THE opening of the twentieth century found the world well prepared for actual conquest of the air. Aviation has been developed to an exact science. It had taken centuries of failure to teach man that he could not fly by flapping his wings like the birds but the idea was at last abandoned. ”

“ The ground under you is at first a perfect blur, but as you rise the objects become clearer. At a height of one hundred feet you feel hardly any motion at all, except for the wind which strikes your face. ”

“ At every stage of this development the aviators are indebted to the birds for information. The successful aëroplanes have great width compared to their depth, they gain stability by flexing the tips of the wings, and their planes are arched upward and forward exactly as are the wings of a bird. The aviator arranges his center of gravity after the same general model, below the planes and well forward. He places his engine forward, just as the bird has its strongest muscles in the chest, and he builds his frame of hollow tubes like the bones of a bird. ”

“ There is no use in wasting time and patience over the machine as it is.
Many a beginner, with mistaken zeal, constructs a too powerful motor. The power in this case turns the propeller too swiftly for it to grasp the air. It merely bores a hole in the air and exerts little propelling force. An ordinary motor when wound up one hundred and fifty turns should take about ten seconds, perhaps a trifle longer, to unwind. It is a good plan to time it before chancing a flight.
Bad bracing is another frequent source of trouble. The planes should be absolutely rigid. ”

“ To store up energy for the flight, simply turn your propeller round and round until the rope of rubber bands is tightly knotted. You can readily tell when it is sufficiently wound and the danger-point is reached, which comes when the pull of the rubber grows too strong for your frame. The average motor should be turned about one hundred and fifty times. When the propeller is released the rubber bands in unwinding will give you back almost exactly the same number of revolutions, less perhaps one or two, which represents the loss through friction. ”

“ It was this book, incidentally, which inspired the Wright Brothers to begin their experiments. Lilenthal was not only a great scientist, but he worked on the principle that an ounce of actual experience was [Pg 182] worth a ton of theory. In aviation, where the weight is all important, this saving was naturally of the greatest importance. Lilenthal built gliders, many of them, and put to actual test the theories which others had merely talked and figured about. Finally he set up an engine on a glider but the machine turned over and he was instantly killed. ”

“ MODEL AEROPLANES
CHAPTER I THE NEW SPORT FOR BOYS
IN the boy’s calendar nowadays the aëroplane season comes in with sledding and runs all through skating, marble, top, kite-flying, and bicycle time. The delights of all the old games seem to be found in this marvelous new toy. The fun in throwing a top cannot compare with that of launching an aëroplane, while kite-flying is a very poor substitute for the actual conquest of the air. ”

“ It is amusing to find that while the birds are always flying before our eyes no one has guessed their secrets. Many attempts have been made to wrest their secrets from them by attaching dynometers to their wings to measure the force of the muscles but little has been learned in this way. One scientist calculated that a goose exerts 200 horse power while another investigator figured out that it was one tenth of one horse power. Many of the theories of flight have been quite as far apart. ”

“ The double motor insures a steadier as well as a longer flight. Always turn the propellers in opposite directions. In flying they must spin around either toward each other or away from each other. If they turn the same way they will give the model a torque which no rudder could possibly overcome.
The efficiency of your motor depends more upon its length than its diameter. In constructing the motor-base, especially for the larger models, arrange to have the strands of rubber bands extend the entire length of your aëroplane, and if necessary, project well forward of the front plane. ”

“ The speed of the craft is remarkable since it has flown for short distances at the rate of forty-seven miles an hour. Its weight, 780 pounds, is not unusual.
An entirely new idea has been introduced in mounting this model. It rests upon only two wheels, one at the front, the other at the end of the central frame. Wheels are also attached to the outer edges of the main plane. When at rest, the model tilts over to one side or the other and rests on one of these wheels. Once the motor has been started, the machine quickly rights itself, as the speed increases, and runs along on two wheels. ”

“ On every hand one sees the inventors tuning up their air-craft for the final test. There are lively discussions [Pg 10] in progress over the marvelous little toys. The layman hears a new language spoken with perfect confidence about him. The boys have already made the picturesque vocabulary of the world of aviation their own. The discussion ranges over monoplanes and biplanes, cellular types, and flexed planes, or of rigid and lateral braces. To hear a crowd of these enthusiasts shout their comments as the air-ships fly about is in itself an education in advanced aëronautics. ”

“ The science of aviation is still so young that there is ample opportunity for invention and discovery for all, and every new trial adds something to our information, and carries the science a step nearer perfection. ”

“ The varying fortunes of the race, the temporary lead gained by one craft, to be lost the next moment to another, which a second later itself falls behind, and the final heat between the survivors in the race as they approach the goal, are enough to drive the average boy crazy with delight. ”