Boys Comparing Models.
The rules for these contests are rigidly observed. Each air-craft is sent aloft by its inventor or owner. The start must be made from a mark, and of course each aëroplane must toe the mark. There must be three judges for each event. One stands at the starting-line and gives the word of command for the start of the race or flight, as the case may be. A second judge stands midway down the course, and the third at or near the finishing-line. 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. The craft must also fly in a reasonably straight line toward the goal, and should it be deflected for any reason and go off at a tangent, the flight, no matter how successful otherwise, will not be counted. In case of a collision between air-craft, the race is repeated. The responsibility for adjusting the power, arranging the steering-gear, and giving direction to the flight at the start is entirely in the hands of the young engineer himself.
In measuring the length of the flights, again, the point at which the air-ship first touches the ground is fixed arbitrarily as the end. Often the little craft merely grazes the ground to rise and skid for many feet, but in the official count this secondary flight is not considered. First and last, no one but the owner of the little craft is permitted to touch it. The grace with which the ship lands is also taken into consideration in granting the prizes. Each boy is permitted three trials. As in the regular aviation world, these records rarely stand for more than a few days at a time.
These air-ships are driven by ropes of rubber bands which are turned on themselves until they are tightly knotted, when in unwinding they serve to drive the propeller around some hundreds of times. 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. As a result, miniature craft of amazing ingenuity and workmanship are being turned out by the amateur aviators all over the country. The materials employed, such as rattan, bamboo, or light lath, and the silk for covering the planes, or the wires for bracing the frame, cost but a few pennies. Toy aviation is one of the most democratic of sports.
CHAPTER II
WHY THE AEROPLANE FLIES
THE aviator must venture in his frail craft upon an unknown and uncharted sea. The great problem is to ride the shifting air currents and keep the machine right side up. Although we cannot see the air currents, we know that they are constantly ebbing and flowing, piling themselves in great heaps, or slipping away in giddy vortices. 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 than water is, of course, far more unstable and baffling. Its supporting power is not only very small but constantly varies. 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.