"Here's the proof of it, fellows!" said Rob just then; and he held up something he had discovered floating on the surface of the water, that already partly filled the cockpit toward the stern of the stranded boat.
"It is a plug, as sure as you live!" ejaculated Merritt. "Let's look at it, Rob!"
One after another they examined the round piece of wood, which had undoubtedly been shaped just to fit the hole bored in the bottom plank.
"That was about the meanest trick I ever heard tell of!" grumbled Tubby, his round face redder than ever with indignation. "If ever I could find out who did it, I'd feel like showing him up to all Hampton, that's what. Here, what's this on the water, fellers? Looks to me like a curled chip, such as would come out when an auger or a brace and bit was used."
"Just what it is, Tubby," added Merritt; "which shows that this measly hole was bored since the last time Rob went sailing. Otherwise, he must have seen the plug when he took out the false flooring to clean the boat."
"It's a queer shaving, boys," continued Tubby, with his head bent low over the object he held in his hand. "See, here, where there's a break all the way along, and right in the middle, too! What would you make of that, Rob?"
"I might be away off in my guess," the other went on to say, after he, too, had closely examined the shaving; "but it seems to me as though that bit must have had a good-sized nick in each half of the biting edge, queer as that would be. As it kept on turning, it left this raised ridge, you see."
"Just what I had in my mind, Rob, give you my word for it," Tubby continued excitedly. "And I'm thinking right now that this ought to be a pretty good clew to prove who made that hole in your boat. All we've got to do is to find a bit with a nick in both tongues that fits this shaving; and the thing is as plain as the nose on Andy's face, here."
"Suppose you leave me out when you're making comparisons, Tubby; but then you're only saying that because you're envious; your own nose doesn't count for much, with such fat cheeks alongside!" Andy burst out.
But Rob considered that what Tubby had said was worth noticing, for he immediately started to congratulate him,—as a patrol leader always should do when one of his comrades has given positive evidences of waking up and noticing things.