“Well, I only hope we get this motor fixed before it rises too much,” and once more Frank gave his full attention to his work on the obstinate engine.

Bluff and Will looked uneasily at each other.

“What does he mean?” asked the latter.

“I think he means that if the wind came up strong the sea would rise, and we couldn’t hold out here with our anchor,” replied Bluff.

“In which case?”

“We’d either be blown out to sea, and be in danger of foundering, or else driven toward the shore, perhaps to stick half a mile off and be wrecked.”

“I don’t like either of those propositions any too well.  Oh!  I hope they get the motor working!  I’m so nervous I feel like shouting; and it seems to me I can hear something moving all the time,” went on Will.

“Something moving?” echoed his companion, looking at him as if he wondered whether the other could be going out of his mind.

“Yes, over there to windward, which, I take it, is about due west just now.  Hark!  Didn’t you hear that?—­and close at hand, too!  What can it be?”

“I don’t know.  Something is moving through the water!  I can hear a gurgle and a creaking noise.  Do you think it could be a boat bearing down on us?  Oh! what if they ran us down in this fog?  I say, Frank!” called Bluff, also excited by this time.

“Well, what now?” demanded the other, again appearing in view.

“There’s something doing over here.  Will thinks it may be a boat coming down on us, full tilt, and liable to grind us to powder.”

Frank listened for just three seconds.  Then he made a dive for a locker, as if he thought the situation more or less desperate.

“What’s he after?” exclaimed Will, amazed.

“That blooming conch-shell horn of Cousin Archie’s.  He’s going to let those chaps know there’s another boat out here, and that they don’t own the earth, that’s what.”

And that was just what Frank meant to do.  Seizing the conch-shell, from which the point had been cut, he blew a piercing blast that could have been heard a mile off.  Again and again he sent out the warning sound, and presently an answering blast came through the dense fog, now swirling madly with the increasing breeze.

“They’re right on us!  There!  I can just make out the top of a mast!  Frank, they will run us down!” shouted Will, while the other continued to blow his horn with renewed vim, and the advancing gulf sponger came plunging straight toward the anchored Jessamine!  It was a thrilling moment for the four chums.

CHAPTER XIV

A CRY ACROSS THE LAGOON

“Keep off, there!” shouted Bluff.

“Luff her, you!” howled Jerry.

“Too-oo-t! too-oo-t!”

Will was the only one of the quartet unable to give utterance to his feelings.  He could only cower there, and gape, while the unknown sailing craft was bearing down straight for the little motor-boat, and apparently bound to smash her in two.