“You’ll laugh when you know what put that idea in my head.” Hal grinned a little sheepishly as he thought about it. “I got it from watching something that never was in any way intended to fly, something that no one ever thought of in connection with flying at all—a player piano!”
“A player piano—huh!” The Colonel turned about so sharply that he nearly spilled the plane model out of his grasp. “How in the deuce did you ever extract an idea on aviation out of one of those contraptions?”
“The thing just came to me all of a sudden one day when I was watching one of those mechanical pianos pounding out that ghostly sort of music where the piano keys press up and down, and the music blares out, but no human hand touches the keys. Through the glass front, I was watching the paper roll in the piano, how it passed in front of a place where air was applied. The air was blown through the little holes in the paper, thus striking the keys and playing the piano. Right then the idea got me that when the airplane gets off the horizontal or longitudinal axis, a stream of air blowing through small holes in a gyroscopic instrument could strike the controls with the strength of a powerful hand, thus bringing the plane back to its normal position—”
“Right O, that’s just what it does, too!” The Colonel thoughtfully spun the wind wheels of the toy and watched how the thing righted itself, no matter how he tilted it. “You’ve got the biggest thing of the age here, boy, if it just works out right in real flying mechanisms! Bring your plans out to the laboratories this week and let’s work the thing out in a real powered model.”
For weeks to come, Hal Dane was up to the ears in work on his gyroscope. And Colonel Wiljohn hung over him like a hen with one chick, as eager as any boy over the outcome of this revolutionary scheme of applying player-piano principles to airships.
At last a model was done, an all-metal miniature, perfect as any real service-flight plane, even to the engine on its nose. But in many phases it ignored the known rules for making the regulation type plane. It had small, fixed wing surfaces, without even an attempt at ailerons. The rear spread into an unknown fantasy of a biplaned tail. On a metal framework above the body of the plane were affixed four limber metal rotor blades that hung with a flimsy droop when the plane was still.
Colonel Wiljohn’s countenance drooped somewhat when he saw the finished product. This model, so much larger than the tiny creation he had balanced on his palm that night in Hal’s room, had an awkward, fearfully flimsy look. Was this the thing he had pinned such faith to a few weeks ago?
Then the motor of the big toy was warmed up. Flimsy blades, that a moment ago had hung limp, now stiffened with the whirl of rotor force to a firmness that would withstand a hundred horse power. Centrifugal force did it! When the whir of its blades gathered power, the thing rose—not with a glide, or a slanting run to take the air, not at all—it rose straight up.
“Beautiful, beautiful!” shouted Colonel Wiljohn, his face tensing with excitement. “I did not believe she could do it!”
Now the little plane was coming down. A mechanism cut the motor dead. The thing stopped in its “tracks,” so to speak, began to drift down in a perfect vertical, the gentle whir of the rotor blades holding the body balanced to every air-bump or current of wind that tended to shift the axis.