till I lock the shop, and then we'll take a little
spin before heading for the campus, just to warm the engine up."

"There's nothing lying around, is there?" asked Andy, anxiously; "in
case a fellow took a notion to break in here while the circus is on in
town, and everybody interested in our biplanes?"

"I've made sure of that," smiled his cousin; adding significantly: "I
suppose you're thinking of Mr. Marsh right now?"

"That's who I am," came the prompt reply. "Don't you see how he would
have loads of time to get in and rummage around, while all of us were
off--even Colonel Josiah is bound to be at the high school building
this p. m. Perhaps Mr. Marsh had that game in mind when he asked so
many questions about the race."

"Oh! you suspicious chap," laughed Frank. "But rest easy, Andy, Mr.
Marsh could look a long while through here without discovering any sign
of my experiments; or at any rate, what success I had met with in the
same. If he goes to all the trouble to get into the shop he'll have
his work for nothing."

"And I'm going to make it a point to keep an eye out for that same
gent," declared Larry, positively; "and if he vanishes from the campus
just you make up your mind your Uncle Larry will be camping on his
trail. I'd just like to see him breaking into a private building, no
matter if it is only the workshop of two boys. Let him try it, if he
wants to see what nice quarters Chief Waller has in the Bloomsbury
lockup. You hear me?"

"After you give us the shove-off, boys, get on your wheels and hike for
the campus. We expect you to be there to start us in the race.
Something depends on a clever get-away, you know," Frank observed, as
he locked the door, and put the key in his pocket.

A short time later the biplane rose swiftly, like a hawk that had been
startled, and began to mount upward in gigantic circles, the faithful
little Kinkaid engine throbbing with the regularity of heart beats.

As directed, no sooner had Larry, Elephant and Nat seen the Bird boys
well off, than they mounted their waiting wheels, brought over for this
especial purpose, and started for town.

Anybody could see without trouble that Bloomsbury was in the throes of
a tremendous excitement that afternoon. People abandoned their houses
in crowds, and flocked toward the campus of the high school, which
seemed to be the hub of a vast wheel, the squads of citizens taking the
part of spokes, all headed toward the commo