Mr. Parker went off alone, to make some further “observations” as he called them, but Mr. Hosbrook warned him never again to speak of his alarming theories.

Mr. Barcoe Jenks called Tom aside just before supper that evening.

“I haven’t forgotten what I said to you about my diamonds,” he remarked, with many nods and winks.  “I’ll show you how to make them, if you will help me.  Did you ever see diamonds made?”

“No, and I guess very few persons have.” replied the lad, thinking perhaps Mr. Jenks might not be quite right, mentally.

The night passed without alarm, and in the morning, at the first blush of dawn, every one was astir, looking eagerly across the sea for a sight of the steamer.

Tom had just come down from the wireless station, having received a message to the effect that a few hours more would bring the CAMBARANIAN within sight of the island.

Suddenly there was a tremendous shock, as if some great cannon had been fired, and the whole island shook to its very centre.

“Another earthquake!  The worst yet!” screamed Mrs. Anderson.

“We are lost!” cried Mrs. Nestor, clinging to her husband.

An instant later they were all thrown down by the tremor of the earth, and Tom, looking toward his wireless station, saw nearly half of the island disappear from sight.  His station went down in collapse with it, splashing into the ocean, and the wave that followed the terrible crash washed nearly to the castaways, as they rose and kneeled on the sand.

“The island is sinking!” cried Mr. Parker.  “Make for the raft!”

“I guess it’s our only chance,” murmured Captain Mentor, as he gazed across the water.  There was no steamer in sight.  Could it arrive on time?  The tremors and shaking of the island continued.

CHAPTER XXV

THE RESCUE—­CONCLUSION

Down to where the small raft was moored ran Mr. Parker.  He was followed by some of the others.

“We must put off at once!” he cried.  “Half the island is gone!  The other half may disappear any moment!  The steamer can not get here on time, but if we put off they may pick us up, if we are not engulfed in the ocean.  Help, everybody!”

Tom gave one more look at where his wireless station had been.  It had totally disappeared, there being, at the spot, now but a sheer cliff, which went right down into the sea.

The women were in tears.  The men, with pale faces, tried to calm them.  Gradually the earthquake tremor passed away; but who could tell when another would come?

Captain Mentor, Mr. Hosbrook and the others were shoving out the small raft.  They intended to get aboard, and paddle out to the larger one, which had been moored some distance away, in readiness for some such emergency as this.

“Come on!” cried Mr. Fenwick to Tom who was lingering behind.  “Come on, ladies.  We must all get aboard, or it may be too late!”