"Then hurry aboard. There seems to be something going on in these waters--perhaps a submarine volcano eruption. We must get away in a hurry!"

The boats came in to the shelving beach. There was a little stretch of water between them and the sand. Through this the castaways waded, and soon they were grasped by the sailors and helped in. In the reaction of their worriment Mrs. Anderson and Mrs. Nestor were both weeping, but their tears were those of joy.

"Give way now, men!" cried the mate in charge of the boats. "We must get back to the ship!"

The sea was now swirling angrily, but the sailors, who had been in worse turmoils than this, rowed on steadily.

"We feared you would not get here in time," said Tom to the mate.

"We were under forced draught most of the way," was his answer.

"Your wireless message came just in time. An hour later and our operator would have gone to bed."

The young inventor realized by what a narrow margin they had been rescued.

"The island will soon sink," predicted Mr. Parker, as they reached the steamer, and boarded her. Captain Valasquez, who was in command, warmly welcomed the castaways.

"We will hear your story later," he said. "Just now I want to get out of these dangerous waters."

He gave the order for full speed, and, as the CAMBARANIAN got under way, Tom, and the others, standing on the deck, looked back at Earthquake Island.

Suddenly there sounded a dull, rumbling report. The whole ocean about the island seemed to upheave. There was a gigantic shower of spray, a sound like an explosion, and when the waters subsided the island had sunk from sight.

"I told you it would go," cried Mr. Parker, triumphantly, but the horror of it all--the horror of the fate that would have been theirs had they remained there an hour longer--held the castaways dumb. The scientist's honor of having correctly predicted the destruction of the island was an empty one.

The agitation of the sea rocked even the mighty CAMBARANIAN and, had our friends been aboard the frail raft, they would surely have perished in the sea. As it was, they were safe--saved by Tom Swift's wireless message.

The steamer resumed her voyage, and the castaways told their story.

Captain Valasquez refused to receive the large amount of money Mr.

Hasbrook and Mr. Jenks would have paid him for the rescue, accepting only a sum he figured that he had lost by the delay, which was not a great deal. The castaways were given the best aboard the ship, and their stories were listened to by the other pa.s.sengers with bated breath.

In due time they were landed in New York, and Mr. and Mrs. Nestor accompanied Tom to Shopton. Mr. Damon, with many blessings also accompanied them, going to his home in Waterfield. Later it was learned that the other boats from the RESOLUTE had been picked up, and the sailors and guests were all saved.

Of course, as soon as our friends had been rescued by the steamer, the wireless operator aboard her, with whom Tom soon struck up an acquaintance, sent messages to the relatives of the castaways, apprising them of their safety.

And the joy of Mary Nestor, when she found that it was Tom who had saved her parents, can well be imagined. As for our hero, well, he was glad too--for Mary's sake.

"I won't forget my promise to you, Tom Swift," said Mr. Barcoe Jenks, as he parted from the young inventor, and what the promise was will be told in the next volume of this series, to be called: "Tom Swift Among the Diamond Makers; or, The Secret of Phantom Mountain." In that Tom is destined to have many more surprising adventures, as is also Mr. Damon, who learned new ways to call down blessings on himself and his possessions.

And now, for a time, we will take leave of the young inventor and also of his many friends, who never ceased to wonder over Tom Swift's skill with the wireless.

THE END

BOOKS BY VICTOR APPLETON

THE TOM SWIFT SERIES

TOM SWIFT AND HIS MOTOR-CYCLE Or Fun and Adventures on the Road

TOM SWIFT AND HIS MOTOR-BOAT Or the Rivals of Lake Carlopa

TOM SWIFT AND HIS AIRSHIP Or the Stirring Cruise of the Red Cloud

TOM SWIFT AND HIS SUBMARINE BOAT Or Under the Ocean for Sunken Treasure

TOM SWIFT AND HIS ELECTRIC RUNABOUT Or the Speediest Car on the Road

TOM SWIFT AND HIS WIRELESS MESSAGE Or the Castaways of Earthquake Island

TOM SWIFT AMONG THE DIAMOND MAKERS Or the Secret of Phantom Mountain

TOM SWIFT IN THE CAVES OF ICE Or the Wreck of the Airship

TOM SWIFT AND HIS SKY RACER Or the Quickest Flight on Record

TOM SWIFT AND HIS ELECTRIC RIFLE Or Daring Adventures in Elephant Land

(Other Volumes in Preparation)