“There’s something queer about his coming around here, boys,” said Jerry. “I don’t like it. Seems to me as if he had more of an object than mere curiosity. We must keep watch of him.”

“It is rather odd that he comes over here so often,” admitted Ned. “It’s quite a distance from his shack, and he doesn’t like walking, or any other exercise.”

But the secret of Joffy’s visits was disclosed the next day, when Andy Rush, all excited and hardly able to breathe, hurried into the tent.

“I seen ’em!” he cried. “Joffy an’ Noddy—talking together—they’re up to some trick—Noddy pointed toward our tent—Joffy nodded his head—then Noddy gave him some money. I’ll bet Noddy’s put him up to all this—to bother you boys.”

“That’s it!” declared Jerry emphatically. “I knew it must be something more than Joffy’s curiosity that brought him here. Boys, this is part of Noddy’s plan to make trouble for us. He’s mad because we’re going to have a better airship than his tin fly that never flew. But we’ll fix him!”

“Let’s make sure that he put Joffy up to it, though,” proposed Ned.

“Oh, that will be easy enough. Wait until the old man comes in again and I’ll tackle him.”

They had not long to wait. That very afternoon the old nuisance sneaked in again, coming under the tent so quietly that he was not noticed until a crash in a corner told that something had happened. Joffy, in reaching up to finger one of the big propellers, had knocked it from the shaft, to which it was not yet fastened. Fortunately, little damage had been done.

“There you are again!” cried Jerry.