"But such contests may come one of these days." The Rover boys were tired out from their day of labor and excitement and ten o'clock found them in their rooms ready to go to bed.

Tom and Sam had started to take off their shoes when there came a faint tap on the door and Bob Grimes appeared.
"Hello, Bob!" cried Tom.

"What can I do for you ?" "Hush! not so loud!" whispered the other student, with a glance over his shoulder down the corridor.

"Listen, both of you," he went on hurriedly.

"Don't ask me any questions, but if you don't want your biplane ruined be sure and guard it closely!" And having spoken thus, Bob Grimes hurried down the corridor and out of sight..