"It's the air," said Stanley.
That evening, after a good meal, the Rover boys had to tell of their various experiences with the biplane. Not a student of Brill had ever gone up in a flying machine although several had gone up in balloons at county fairs and elsewhere. The Rovers had to promise to take up half a dozen of their chums. So far during the fall, talk of football had filled the air, but now all became flying and flying machines. Several of the richer students promised themselves machines in the near future.
"That's the talk!" cried Tom, enthusiastically. "Then we can have some races!"
"Maybe we can even get up an intercollegiate aeroplaning contest," remarked Sam.
"I'm afraid it's a little too early for that yet," answered Dick. "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
