“Not with the roosters crowing like they are,” said Andy confidently.  “But just glimpse the black box would you, Frank?”

“I am looking,” returned the other.

“He calls it the receiver for his new butterflies, but looks more like a kodak to me,” Andy went on.  “But d’ye know what I thought, Frank?”

“Tell me,” whispered the other, still watching the professor, who had come to a stop at some little distance away, and seemed to be busily engaged looking back of him, as though laying out plans for an afternoon campaign among the bright winged butterflies.

“Why, how easy for him to tear out the inside works of a camera box like that, and make use of it for a better purpose, see?” Andy went on to say.

“Oh! now you’ve got a bright thought for a fact,” Frank sent back, careful not to raise his voice above that cautious pitch.

“Well, it could be done; and I guess that little black box’d hold about all the money and securities that the bank lost.  They say the thieves only picked out the papers they could dispose of, and left all the rest, which would indicate that the second yegg must have been in the banking line, some time or other, and knew what was what.”

“H’sh! he’s coming on again!  Lie low, now; Andy!”

Accordingly both of them remained perfectly motionless as the professor advanced toward the house.  Had he shown any disposition to head toward that particular corner Frank was ready to assume an attitude of indifference and appear to be engaged in some boyish game with his jack knife, tossing it up in the air, and causing the point of the long blade to stick upright in the ground.

But the small man with the brown glasses and the butterfly net made straight for the front porch of the house, and passed in at the door, just as though he felt perfectly at home there.

“Well, what next?” remarked Andy.

For reply the other beckoned, and started hurriedly to gain the shelter of the woodshed near by.

“What’s this for?” questioned Andy, when they were once more crouched down, in a position where they could not be easily seen.

“Stop and think,” answered the other; “if he just happened to look out of a window on this side of the house he’d see us easily and our suspicious actions would tell him we were on to his game.  Now even if he looks he won’t see anything.”

“Huh! and do we stay here all afternoon just doing nothing; while p’raps he’s taking a nap indoors?” grumbled the other, who wanted to be moving, and was never satisfied when not in action.

“Wait!” was all Frank would say.

Perhaps he could see further ahead than his cousin, and guessed something of what was likely to occur.  They had not taken pains to warn Sallie or her mother to keep from mentioning the fact of their happening around; and chances were, that as soon as Casper Blue heard that the Bird boys had dropped in, he would become immediately suspicious.