for he had to use all his lung power to be heard above that racket. "Did it explode?"
"Explode nothing!" shouted Tom. "That's the re-built motor in action."
"In action! I should say it was in action. Is it always going to roar like that?"
Indeed the motor was roaring away, spitting fire and burnt gases from the exhaust pipe, and enveloping the aeroplane in a whitish haze of choking smoke.
"No, I have the muffler cut out, and that's why she barks so. But she runs easier that way, and I want to get her smoothed out a bit."
"Whew! That smoke!" gasped his chum. "Why don't you—whew—this is more than I can stand," and holding his hands to his smarting eyes, Ned, gasping and choking, staggered away to where the air was better.
"It is sort of thick," admitted Tom. "But that's only because she's getting too much oil. She'll clear in a few minutes. Stick around and we'll go up."
Despite the choking vapor, the young inventor stuck to his task of regulating the motor, and in a short while the smoke became less, while the big propeller blades whirled about more evenly. Then Tom adjusted the muffler, and most of the noise stopped.
