“Humph!  There was no use of alarming them.  We’ll be back long before they want to come aboard again.”

“In that case I’ll have nothing more to say.”

“Don’t you believe it?”

“I’m bound to believe it, if you say so.”

“Don’t get impudent, young man!”

“I am not impudent, and you needn’t get impudent either!” cried Fred, his anger rising.  “You are in command here, but this boat is under charter and just now I represent the man who owns that charter.  If you have got to cruise around to test the engine and shaft well and good, but if you are merely cruising around for the fun of it I say go back to where we came from—­none of us want to do any cruising today.”

At this plain speech the mate grew purple in the face.  He raised his hand as if to strike the youth, but just then Aleck came on deck, carrying a pitcher of ice water in his hand.

“Stop dat!  Don’t yo’ go fo’ to hit dat boy!” cried the colored man.  “If yo’ do I’ll fling dis watah pitcher at yo’ head!”

“You shut up, you rascally nigger!” shouted the mate.  “You have nothing to say here!”

“I’se got somet’ing to say if yo’ hit Massa Fred,” answered Aleck, and held the water pitcher as if ready to launch it at the mate’s head.

There was a moment of excitement and several crowded around, but then the mate waved the crowd away.

“I shall report this to Captain Barforth as soon as he comes back,” he said, and turning on his heel, he walked off.  Fred went down into the cabin, and Aleck followed him.  A few minutes later Norton joined the youth and the others, who had gathered to talk the matter over.

“We must be on the watch,” said the chief engineer.  “I am certain now that Carey is up to some game.”

A long discussion followed, but nothing came of it.  The steam yacht kept on its way and rounded the eastern point of Treasure Isle.  Then it stood to the north westward.

“I hope he knows his course,” said Norton, to the boys.  “If he doesn’t he stands a good chance of running us on some key or reef.”

If the boys were excited, the girls and ladies were more so.  Nobody knew exactly what to do, and each minute added to the general anxiety.

At last the vessel rounded another point of the isle and came in sight of the sea beyond.  There in the distance was a steamer at rest on the waves, and Fred and Hans felt certain she must be the Josephine.

The two vessels were soon close together.  As the Rainbow came up to the other craft, Walt Wingate went to the rail and shouted something through a megaphone which the mate loaned him.  Immediately came back an answering cry, but the boys did not catch what was said.

“This is going pretty far,” said Fred, to Frank Norton.  “Don’t you think I ought to step in and stop it?”

The chief engineer shrugged his shoulders.

“Carey is really in command and it might be called mutiny to do anything to stop him.”