“These movable sections of the planes, the first unique feature of the new airship, telescope within and without the standard sections of the wings. By means of the gauge and spring drums they are extended automatically when the machine is not in swift flight. When the craft has made an ascent and attained a speed sufficient to create a vacuum under the dipping or front edge of the planes, the suction or reverse pressure on the gauges allows the drums to reel in the extension surfaces. When in full motion, as these come in, speed is naturally increased and all the extensions are housed securely beneath or over the main section of the wing.”
“How about the wing trusses?” broke in the skeptical Glidden.
“Corrugated rigidity,” replied Stewart promptly, remembering the phrase he had heard applied to the long, untrussed wings.
“The first section or extension,” his story continued, “running in its grooves, so closely overlaps the outside of the main section as to appear to be its proper covering. The rear section, with separate leaves, like the feathers of a bird’s wing, likewise disappears, leaving only the long narrow wing which has always been the ideal speed machine.
“To drive this huge craft, whose body consists of two stories or decks with pilot house, staterooms, fuel chambers, engine room, bridges above and protective galleries, a much higher percentage of motor power than ever secured before had to be turned into propulsive energy. The waste, or ‘slip’ of the ordinary propellers not only allowed a great deal of the motor’s power to escape, but it applied the remaining power so far from the shaft of the propeller that the resultant leverage greatly reduced the actual thrust.” (As Stewart finished this sentence, after several pauses and corrections, he turned the page over to Glidden with some pride. Then he paused while the older reporter read it.)
“Is that right?” asked Stewart with a curious smile.
“Absolutely,” answered Glidden. “What’s next?”
Stewart’s typewriter began clicking again.
“The new French ‘moon propeller’ does away with this ‘slip’ and allows the full power of the engine to be applied advantageously. Viewed sidewise this new form of propeller looks exactly like the new moon, its tips bending ahead of its shaft attachment. Its object is to gather the air at the outside of the circle,—”