had strengthened
their belief that during all the centuries of travel it had been lost
from man's memory and hidden from his view. Now this very isolation,
since they were unable to locate this island, if indeed it existed at
all, threatened to be their undoing.

Still they circled and circled with great, untiring sweeps. At last,
releasing the searchlight, Vincent put his lips to a speaking tube.

"Let's light," he grumbled. "I'm dead. What's the use?"

"What else can we do but keep looking?" Alfred answered.

"Take a look at the gas. Maybe it will carry us back."

Even as he spoke, a strange thing happened. The air appeared suddenly to
have dropped from beneath the plane. Straight down for fifty feet she
dropped.

With the utmost difficulty Alfred succeeded in preventing her from
taking a nose dive into the sea.

"She--she bumped," he managed to pant at last. "Something the matter
with the air."

And indeed there was something about the atmospheric conditions which
they had not sensed. Busy as they had been they had not seen the black
bank of clouds to the northeast of them. With the wild rush of air from
sheer speed, they had not felt the increasing strength of the gale. Once
Vincent had fancied that the sea, far beneath them, seemed disturbed,
but so far beneath them was it that he could not tell.

Now in surprise and consternation, as if to steady his reeling brain, he
gripped the fuselage beside him while he shrilled into the tube:

"Look! Look over there! Lightning!"

"Watch out, I'm going down," warned the other boy. "Going to light."

To do this was no easy task. Three times they swooped low, to skim along
just over the crest of the waves, only to tilt upward again.

"Looks bad," grumbled the young pilot.

The fourth time, he dared it. With the spray spattering his goggles, he
sent the plane right into the midst of it. For a second it seemed that
nothing could save them, that the wave they had nose-dived into would
throw their plane end for end and land her on her back, with her two
occupants hopeless prisoners strapped head down to drown beneath her.

But at last the powerful motors conquered and, tossed by the ever
increasing swells, the plane rode the sea like the stormy petrel after
which she had been named.

"Quick!" exclaimed Alfred as the motors ceased to throb. "Strip off your
harness and get back to the tank."

A moment later Vincent was making a perilous journey to the gas tank.