“It must be somewhere here,” he said; and he had a consultation with the two mates, who both agreed that they were near the spot, though no point was visible.

The change of course produced no good effect, and after sailing here and there for several days the captain decided to make for the island where they had landed to have the day’s shooting.

This was reached with the greatest of exactness, and then, after examining the spot where the little engagement had taken place, a fresh start was made, and the vessel’s course laid in a direction which they all felt must go over the same ground as the boat had drifted, and the ship had been carried after the fire, and she had gone ashore.

“Breakers ahead!”

“Ah! I thought we should manage it this time,” said the captain eagerly, as, followed by Mark, he hurried on deck the next morning in the grey light, and there before them was a long curving reef of coral bending round to north-west and south-west, and inclosing smooth water apparently in a ring.

“Why, Gregory!” exclaimed the captain.

“Yes, sir; that’s it!” said the mate.

“Nonsense!” cried Mark, laughing at what seemed to him a joke. “Where’s the mountain?”

Where indeed!

With very little difficulty the opening in the reef was found, and a boat lowered and rowed into the lagoon, where the lead was lowered several times but no bottom found.