“I’ll be glad to see this professor of yours, Durham,” said Mr. Strapp.

“Hello!” broke in Pep, abruptly. “Here’s somebody.”

The door of the little office swung open as someone knocked timidly on it.

Frank, craning his neck, discerned a man standing still and apparently awaiting an answer to his summons. It struck Frank that the visitor must be near-sighted, or very absent-minded, to thus mistake a wide open door for a closed one.

“Come in,” he sang out and the caller seized the knob of the door. As he did this, the unexpected ease with which the door swung towards him moved him off his balance, drove him back and banged shut, quite taking him off his feet.

“Stupendous!” gasped the caller, as he went sprawling upon the floor headlong, his tall silk hat rolling in one direction, the goggles he wore in another.

“Why!” cried Frank, “It’s Professor Barrington himself!”

CHAPTER II
AN ABSENT-MINDED VISITOR

“Outrageous—unpardonable!” gasped the professor, as he struggled to his feet, thus rudely aroused from his habitual abstraction.

Pep stooped to pick up the rolling hat and to hide a grin. Randy, as he rescued the glasses, bit his lip to keep his face straight. Even Mr. Strapp was amused; but he did not allow himself to show it.