straining eyes. He toiled in partial
delirium, and it seemed to him that he was looking again at the
phantasmagoria of the Coston lights on the fog when the yachtsmen were
serenading the girl of the Polly. He found himself muttering, keeping
time to his chisel-blows:

"Our Polly O,
O'er the sea you go--"

In all the human emotions there is no more maddening and soul-flaying
terror than the fear of being shut in, which wise men call
claustrophobia. Mayo had been a man of the open--of wide horizons,
drinking from the fount of all the air under the heavens. This hideous
confinement was demoralizing his reason. He wanted to throw down his
hammer and chisel and scream and kick and throw himself up against the
penning planks. On the other side was air--the open! There was still one
side of the square to do.

Again that comforting little hand touched his shoulder and he was
spurred by the thought that the girl was still courageous and had faith
in him. He groaned and kept on.

Lapse of time ceased to have significance. Every now and then the hammer
slipped and bruised his hand cruelly. But he did not feel the hurt. Both
tools wavered in his grasp. He struck a desperate--a despairing blow and
the hammer and chisel dropped. He knew that he had finished the fourth
side. He fell across Polly Candage's lap and she helped him to his
knees.

"I'm done, men," he gasped. "All together with those joists! Strike
together! Right above my head."

He heard the skipper count one--two--three. He heard the concerted blow.
The planks did not give way.

"We don't seem to have no strength left," explained the mate, in hoarse
tones.

They struck again, but irregularly.

"It's our lives--our lives, men!" cried Mayo. "Ram it to her!"

"Here's one for you, Captain Mayo," said Candage, and he thrust a length
of plank into the groping hands.

"Make it together, this time--together!" commanded Mayo. "Hard--one,
two, three!"

They drove their battering-rams up against the prisoning roof. Fury and
despair were behind their blow.

The glory of light flooded into their blinking eyes.

The section had given way!

Mayo went first and he snapped out with almost the violence of a cork
popping from a bottle. He felt the rush of the imprisoned air past him
as he emerged. Instantly he turned and thrust down his hands and pulled
the girl up into the open and the others followed, the lumber pushing
under their feet.

It se