“I understand,” said Bob.
“An’ when the gas in the big envelope expands it simply presses on the little balloon, forces out some of the air through a valve, and, in that way, gets room enough without doin’ any damage.”
“A mighty slick scheme.”
“And when the gas contracts the motor drives more air into the balloonette, which fills out and keeps the big envelope inflated.”
“Sure thing,” remarked Bob. “It regulates the pressure, so that they don’t have to let the gas escape.”
“That’s it, exactly! Of course, though, we’re bound to lose some through leakage. The framework o’ the car is made of light steel tubing. In the middle is our gasoline motor. These big screw propellers, just abreast on either side, are worked by shafts. The boss, if he happens to be in a good humor, may let you go aboard.”
“I only hope he will,” said Bob. “Those planes at the front and rear ends are to maintain the vertical equilibrium, I suppose?”
“Them big words don’t faze you, I see. Yes; you’ve struck it. And the rudder, of course, is at the rear. Wait a second; I’ll speak to the boss.”
Kindale walked rapidly away, soon returning, his face wearing a good-natured grin.
“It’s all right, Bob; he says you may climb aboard. Be a little careful, for it ain’t like gettin’ in an’ out of a Pullman.”