“You win,” laughed Hal.  “But here’s a better way to handle the subject in view of another duty before us.  You know we’re supposed to try to get in touch with somebody by radio at Rockport and we haven’t much time to spare before the Catwhisker arrives there.  You get busy on the job and I’ll take care of the dishes.”

“Not on your lightning switch,” returned Bud emphatically.  “I volunteered to be Friday, and I’m not going to slip out of my promise through your generosity.  You get busy with the key and the phones and I’ll get busy with the dishrag.”

As no reasonable argument could be adduced to defeat this proposition, the two boys were soon busy as prescribed by the last speaker.  Bud’s task required only about fifteen minutes, and after it was finished he rejoined his companion at the radio table.

“Well, what luck?” he inquired.

“Nothing doing,” Hal replied.  “I’ve managed to get the calls and waves of two amateurs at Rockport, but neither of them answers.”

“Keep it up anyway,” Bud urged, “and I’ll take a tackle and go over to the place where we took in our haul of fish yesterday, and see what I can do this morning.  Call me if you get anything interesting.”

Hal promised to do as requested and then Bud hurried away.  The former continued his efforts unsuccessfully with the sending key for nearly half an hour, hearing no sound from his friend in the meantime.  Then he was about to take the receivers from his ears and go in search of the fisher-boy to find out what success he had had, when the latter appeared on the scene with a look in his face that startled the youth at the radio table.

“What’s the matter, Bud?” Hal inquired, as he literally tore the phones from his ears.  “Has anything happened?”

“Not exactly,” the other replied.  “But I’ve made a discovery that may mean trouble for us.  At least, we’ll have to be on the lookout from now on.”

“Why—­what do you mean?  Hurry up; don’t keep me in suspense.  What kind of discovery have you made?”

“I’ve discovered that we’re not the only persons on this island,” was Bud’s chilling response.

CHAPTER XVIII

Unwelcome Visitors

“Why, Bud, what do you mean?” Hal demanded, in astonishment.  “Who else is on this island?”

“Some men.  I don’t know how many,” Bud replied in cautious tone.  “I heard them talking about us.  But keep your voice low, for this island is small and they may hear you.”

“I was going to remark that this is a small island to contain much of a hiding place for anybody.”

“Yes, but it’s wild with bushes.  And these men are bad fellows, I could tell from the way they talked about us.  They’re as mad as hops ’cause we’re here.  They’re studying how to get rid of us without making more trouble for themselves.”

“That’s funny,” Hal remarked.  “Why should they care if we’re here?  Do they claim they own this island?”