bicyclist has been seen there. I hope you can describe the wheel so they
might know it."

"Yes, I even know the number. Besides, I've got my address scratched on
the under-part of the frame. But whatever do you suppose Jules wanted to
set our hangar on fire for?" Frank asked.

"Huh!" replied the chief; "don't know, unless it was a spirit of
revenge. Some of these French rascals have the same nature as the
Corsican or the Sicilian and hug the idea of revenge to their hearts."

"Revenge!" Frank cried. "But when did we ever injure them? Oh, yes, I
forgot! We chased them off at the time they tried to steal our
aeroplane, and they even neglected to take those two suit cases of
jewelry with them, so the stolen property was recovered."

"Yes," the chief went on, "and that wasn't all, either. Remember that it
was you Bird boys who discovered that they were hiding in the old shack
deep in the forest. You saw them near there when you were sailing over
that region in your airship and reported to me. And so we surrounded the
cabin and nabbed our game. It may be they learned who gave them away,
and Jules, on finding himself at large, made up his mind to get even
before running off."

Turning to the phone on his desk the chief now started to call up
several of the neighboring towns. Some were only six or eight miles
away, while others might be double that and more.

Frank knew where the road ran that passed the Whympers place and when
finally the police head got Shelby he pricked up his ears. Immediately