“Let’s look up Castle Island,” said Jack, partly to relieve the tenseness of their position as the wounded ship crawled strickenly southward and partly to keep Sam, who was making a plucky effort to fight back his fears, from thinking too much of their situation.

They soon found it—a small island shaped like a splash of gravy on a plate. It was marked with a red dot. Under this red dot, in italics, was written, “Volcano. Probably extinct.

“Well, any old port in a storm,” remarked Jack, as he closed up the atlas.

[CHAPTER XXXIX—JACK’S RADIO]

Darkly violet under the light of the dawn-fading stars lay Castle Island. Cradled in the heaving seas it was watched by scores of anxious eyes on the Tropic Queen, now in her death struggle. The fire room crew was kept at work only by physical persuasion. The water was gaining fast now through the jagged wound in the craft’s steel side.

In the soft radiance that precedes the first flush of a tropic dawn, the two young wireless men, their occupation gone, watched its notched skyline grow into more definite shape.

As the light grew stronger, they saw that it was a bigger island than they had supposed. Vast chasms rent the sides of rock-ribbed mountains, and the place looked desolate and barren to a degree. Suddenly, too, Jack became aware of something they had not at first noticed.

From the summit of the rocky apex that topped the island, a smudge of smoke was blurred against the clear sky.

“The volcano!” exclaimed the boys in one breath.

“But I thought it was extinct,” said Sam, in a dismayed voice. The thought of being in the proximity of an active volcano was anything but pleasing to him.