Out of the midst of these waves, with their alternations of light and shadow, a deep plaintive voice sent up a cry, the tones of which thrilled through every fiber of their being.

"Come! come!" were the words which fell on their ears.

They both started up and leaned over the railing, and peered into the gloom with questioning eyes.

"Mary, you heard that? You heard that?" cried Robert.

But they saw nothing but the long shadow that stretched before them.

"Robert," said Mary, pale with emotion, "I thought--yes, I thought as you did, that--We must both be ill with fever, Robert."

A second time the cry reached them, and this time the illusion was so great, that they both exclaimed simultaneously, "My father! My father!"

It was too much for Mary. Overcome with emotion, she fell fainting into Robert's arms.

"Help!" shouted Robert. "My sister! my father! Help! Help!"

The man at the wheel darted forward to lift up the girl. The sailors on watch ran to assist, and John Mangles, Lady Helena, and Glenarvan were hastily roused from sleep.

"My sister is dying, and my father is there!" exclaimed Robert, pointing to the waves.

They were wholly at a loss to understand him.

"Yes!" he repeated, "my father is there! I heard my father's voice; Mary heard it too!"

Just at this moment, Mary Grant recovering consciousness, but wandering and excited, called out, "My father! my father is there!"

And the poor girl started up, and leaning over the side of the yacht, wanted to throw herself into the sea.

"My Lord--Lady Helena!" she exclaimed, clasping her hands, "I tell you my father is there! I can declare that I heard his voice come out of the waves like a wail, as if it were a last adieu."

The young girl went off again into convulsions and spasms, which became so violent that she had to be carried to her cabin, where Lady Helena lavished every care on her. Robert kept on repeating, "My father! my father is there! I am sure of it, my Lord!"

The spectators of this painful scene saw that the captain's children were laboring under an hallucination. But how were they to be undeceived?

Glenarvan made an attempt, however. He took Robert's hand, and said, "You say you heard your father's voice, my dear boy?"

"Yes, my Lord; there, in the middle of the waves. He cried out, 'Come! come!'"

"And did you recognize his voice?"

"Yes, I recognized it immediately. Yes, yes; I can swear to it! My sister heard it, and recognized it as well. How could we both be deceived? My Lord, do let us go to my father's help. A boat! a boat!"

Glenarvan saw it was impossible to undeceive the poor boy, but he tried once more by saying to the man at the wheel:

"Hawkins, you were at the wheel, were you not, when Miss Mary was so strangely attacked?"

"Yes, your Honor," replied Hawkins.

"And you heard nothing, and saw nothing?"

"Nothing."

"Now Robert, see?"

"If it had been Hawkins's father," returned the boy, with indomitable energy, "Hawkins would not say he had heard nothing. It was my father, my lord! my father."

Sobs choked his voice; he became pale and silent, and presently fell down insensible, like his sister.

Glenarvan had him carried to his bed, where he lay in a deep swoon.

"Poor orphans," said John Mangles. "It is a terrible trial they have to bear!"

"Yes," said Glenarvan; "excessive grief has produced the same hallucination in both of them, and at the same time."

"In both of them!" muttered Paganel; "that's strange, and pure science would say inadmissible."

He leaned over the side of the vessel, and listened attentively, making a sign to the rest to keep still.

But profound silence reigned around. Paganel shouted his loudest. No response came.

"It is strange," repeated the geographer, going back to his cabin. "Close sympathy in thought and grief does not suffice to explain this phenomenon."

Next day, March 4, at 5 A. M., at dawn, the passengers, including Mary and Robert, who would not stay behind, were all assembled on the poop, each one eager to examine the land they had only caught a glimpse of the night before.