The empire of the air is truly named; it has fostered the marked development of a new science of the air—aerology. It has spurred radio technicians to new inventions and new discoveries; its roaring machines burn some $12,000,000 worth of oil land fuel annually and its greedy engines have demalided—and research technicians have met the demands— a higher and higher octane fuel.
r the aviation industry is com-Drehensive and now so much a part of American life that the curious who gaped amazed at Wright and Curtiss and Latham three decades ago now would feel confused and lost without the humdrum sound of great wings roaring through the skies, with. out the casual sight of man—fying.
And that age-old dream of Daed-alns is reaching full maturity at last in the long assembly lines at the aircraft factories—for better in the new and greater DE-4's; the flying Clippers, the commercial air liners which span seas and girdle continents; for worse in the new, more deadly and ever larger military flying fleets which brood like swarming hosts of death and destruction above the world.
The aircraft factory is the kingpin, the keystone in the whole complicate ed structure of the aviation industry. Although the plants which manufacture planes, engines and equipment represent perhaps only about one-sixth of the total investment in the industry, nevertheless they set the pace, they blaze the tral in man's conquest of the empire of the sky.
We have come a long way since ihe days of the old bicycle shop in Dayton where the Wright brothers dreamed of a crate that flew, but the principles back of the aircraft factory are the same. And today other men are dreaming their blueprint dreams in the engineering divisions of a dozen plants so that tomorrow 3,000 horse-power engines, 125-ton "planes may fly the air. For the factories are the centres of research and invention and development, as well as the manufáctories of practical flying machines.
They are the incubators of aerial knowledge; the alma maters of countless pilots, "mech" (mechanics), technicians, flying salesmen and specialists, who become human laboratories, individual researchers in the flying game. -The things they learn, the knowledge these sons of the factories gain in the field comes back again eventually io the fountain head and repository of almost all knowledge in the aviation industry—the factor; model and the test stand for the new engine are the practical labor-atones of the research engineers, for in these gigantic "test tubes" are born the planes, the engines of tomorrow. Wind tunnels are -what their names imply—great bell-throated tunnels through which a blast of air driven by giant fans moves at tremendous speed. The research engineers build a small but precise model of their dream-plane, anchor it tighUy in the air flow of the wind tunnel and by means of complicated instruments measure the model's efficiency, Model after model may be built, ihe wings reshaped here, the fuselage streamlining perfected, the positions of the motors altered. Sometimes—but rarely—the original model "flies" so well in the blast of the wind tunnel that its design is adopted; more often there are repeated changes—as in the case of a recently announced two-engined Curtis transport plane, for which nine different models of wings were tried in the wind tunnels.
The test stand where experimental engines are run, tinkered with and run some more is the laboratory of the engine builders; delicate instruments record the engine's performance. And thus, by trial-and-error methods and painstaking, precise work, the research' engineers arrive at last at a suitable design for their planes of tomorrow.
Text read from the printed page and cleaned; old type leaves the occasional error.