Jack nodded.

"He went away for a while. I guess he went home for lunch, but he came back. He's patient. I'll say that much for him. He's up in the tree now, with a pair of field-glasses."

"The genuine detective!" said Chet approvingly. "Does he know you saw him?"

Jack shook his head.

"We didn't pay any attention. I suppose he thinks he's been very clever."

"Well, if he likes sitting in a tree so much, he'll have enough to suit him for a long while. You have a dog, haven't you, Jack?"

Jack nodded. "A bulldog. I'll call him." He whistled sharply, and in a few minutes an extremely ferocious looking bulldog came around the corner of the house, wagging his tail.

"Fine! Got a chain for him?"

The boys looked at Chet, puzzled, but Jack went away and returned with a long chain, which he attached to the dog's collar.

"I don't think you should let a dog run around loose," said Chet gravely. "It isn't good for him. I think he'd better be chained up. And if you'll show me just which apple tree contains our detective friend I'll show you the apple tree that should shelter Towser."