Spurling.

Producing a coil of line, he took three or four turns round Percy's
waist, and lashed him fast to the bails. He did the same for himself.

"Guess we'll stick on now," he remarked.

"Where did you get that rope?" asked Percy.

"It's all that's left of the ground-line. Thought it might come in
handy, so I jammed it inside my oil-coat before I jumped. Never can tell
when you'll need a few feet for something or other."

The screech of the buoy, recurring regularly, set their ears ringing.

"We've got to choke that off!" exclaimed Spurling, finally. "We'll go
crazy, sure, if we have to listen to it all night."

"How'll you do it? Jam something into the mouth of the whistle?"

"Might smother it that way, but I know an easier one."

He pushed his handkerchief into the curved end of the intake tube just
as the bellowing buoy reached its lowest point. The next time it sank
there was no sound.

"Can't sing out unless it fills up with air," remarked Spurling. "It's
human, so far!"

"Is it all right to shut the signal off altogether? Mightn't some vessel
strike the shoal if she doesn't hear it?"

"Not much chance of that to-night! Everything'll give Cashe's a wide
berth in a norther. But I'll let it scream a few times every ten
minutes. That'll be often enough to warn off any craft within
hearing."

[Illustration: THEY STOOD CLOSE TOGETHER ON THE CIRCULAR TOP, HOLDING ON
TO THE CROSSED BAILS, WAIST-HIGH]

The last red embers of the sunset died out, and from horizon to horizon
the sky was ablaze with stars. Even the boys, wet, hungry, and
exhausted, could not be blind to such magnificence.

"Good evening to study astronomy, Perce!"

"Never saw a finer! But I'd want a steadier foundation than this for my
telescope."

As on the previous night, the sea was aglow with phosphorescence. Every
wave was crested with silver. Buoy and tugging dory kept the water alive
with light as they rose and fell. Leeward the long shoal broke in
glittering foam.

Spurling gazed silently down into the eddying tide.

"Runs fast, doesn't it?" said Percy.

"Yes; it's the ebb out of Fundy. Comes piling down over Cashe's at a
two-knot rate. When the flood begins it'll run just as hard the other
way. That's what makes the shoal so dangerous. There's only from four to
seven fathoms over the ledge at low water, and that's little enough in a
storm."

"Were you ever down here before?"

"No; but I've heard Uncle Tom Sprowl tell