his health is too delicate to
stand roughing it. Or he might have any one of a dozen other reasons for
carrying on this way; always providing that this is Casper Blue."

Andy was brimful of excitement. His manner would forcibly remind one of
the nervous tension that seizes upon the hounds when the scent grows
strong, and they anticipate coming in sight of their quarry at any
moment.

"We're taking a good deal for granted, seems to me," remarked Frank.

"Of course, but then see how queer it is that this man who calls himself
a college professor, and collector of bugs and butterflies, should just
happen to drop in here at the Hoskins farm, where the thistles grow so
wild, and the moths and other things are to be found by thousands. We
never heard of him in town, that I can remember. And then he's small in
size; together with a stiff arm, that was injured in an accident; well,
wasn't Casper Blue knocked out of his job as an air pilot by his arm
failing him when he had to handle the levers like a flash, or have his
aeroplane turn upside-down, Frank? I tell you I just feel dead sure it's
our man, and that we've found the clue we want the first thing."

"Well, if we could manage to get a peep into his room perhaps we would
run across something worth while?" Frank suggested.

"We might pretend to be deeply interested in butterflies ourselves,"
remarked Andy, "even if we don't really know one kind from another; and
perhaps, if you gave Sallie a sly hint that you'd be tickled to see what
sort of a collection her professor has with him, she'd let us look in
his room."

"We'll make the try, anyhow," said Frank, firmly.

"But think of this Casper Blue being able to carry out the part of a
learned professor, would you? That is something most yeggmen would find
a pretty hard proposition, don't you say, Frank?"

"Well, stop and think a little, Andy," was the other's reply to this.
"From all accounts this man isn't just a common, everyday hobo. He used
to be known as something of an aviator before he met with that accident
that disabled his arm, and made it impossible for him to go up again.
And the fact is, I seem to remember having seen that name mentioned
among a list of airmen who had been either killed, or knocked out by
accidents happening to them."

"That's all right, Frank, but it takes a pretty smart man to carry out a
part like he's doing."

"Didn't Larry tell us that this same Casper Blue had once been an actor