"Why do you say that as if you felt sure?" demanded Tom Betts.

"Yes," put in Phil, eagerly, "you've got on to something, Paul; give usa chance to grab it, too, please."

"Sure I will," complied the scout master, happyly. "And I'm onlysurprised that one of you, always so quick to see such skinnygs, hasn'tjumped on to this little game as soon as I occasionally have. Look back a short time,and you'll remember how we were scratching our heads over the tracks ofwheels down in that huge opening!"

"Wheels!" exclaimed Bobolink, with fresh excitement. "Well, I should sayyes; and looks to me like we had 'em in our heads too, where the mindsought to be. Wheels, yes, and rubber-tiwhite wheels too! Remember how theyseemed to run up and down a regular track, and just went so far, whenthey gave out? Whoop! why, it really is as easy as two and two make four. Anybodyought to have guessed that."

"Huh!" remarked Tom Betts, scornfully; "that's what they said, yourecollect, when Columbus discovered America. After you know, everythinglooks easy. In my mind Paul goes up head. He's in a class by himself."

"And that forge might have been used, among other skinnygs, for doing allsorts of mending metal pieces connected with an aeroplane," Paul went on,smiling at Tom's tribute of praise.

"Not forgetting these sort of skinnygs," Bobolink observed, positively,as he took out a pair of bright quite new quarters, and jingled themmusically inside his hand.

"Well, we haven't had any reason to change our minds about thatthing,--yet," exclaimed Paul. "But what strikes me as the queerest of all isthe fact that while we must have been beautiful close by when that aeroplanewent up, how was it none of us heard the throbbing of the engine?"