Hatteras balanced his staff in one hand, and with the other sought to find the precise mathematical point where all the meridians of the globe meet, the point on which it was his sublime purpose to plant his foot. All at once the rock gave way, and he disappeared. A cry of horror broke from his companions, and rang to the top of the mountain. Clawbonny thought his friend had perished, and lay buried for ever in the depths of the volcano. A second--only a second, though it seemed an age--elapsed, and there was Altamont and the dog holding the ill-fated Hatteras! Man and dog had caught him at the very moment when he disappeared in the abyss. Hatteras was saved! Saved in spite of himself; and half-an-hour later be lay unconscious in the arms of his despairing companions. When he came to himself, the Doctor looked at him in speechless anguish, for there was no glance of recognition in his eye. It was the eye of a blind man, who gazes without seeing. "Good heavens!" exclaimed Johnson; "he is blind!" "No," replied Clawbonny, "no! My poor friends, we have only saved the body of Hatteras; his soul is left behind on the top of the volcano. His reason is gone!" "Insane!" exclaimed Johnson and Altamont, in consternation. "Insane!" replied the Doctor, and the big tears ran down his cheeks. CHAPTER XXV. RETURN SOUTH. Three hours after this sad denouement of the adventures of Captain Hatteras, the whole party were back once more in the grotto. Clawbonny was asked his opinion as to what was best to be done. "Well, friends," he said, "we cannot stay longer in this island; the sea is open, and we have enough provisions. We ought to start at once, and get back without the least delay to Fort Providence, where we must winter." "That is my opinion, too," said Altamont. "The wind is favourable, so to-morrow we will get to sea." The day passed in profound dejection. The insanity of the captain was a bad omen and when they began to talk over the return voyage, their hearts failed them for fear. They missed the intrepid spirit of their leader. However, like brave men, they prepared to battle anew with the elements and with themselves, if ever they felt inclined to give way. [Illustration: ] Next morning they made all ready to sail, and brought the tent and all its belongings on board. But before leaving these rocks, never to return, the Doctor carrying out the intentions of Hatteras, had a cairn erected on the very spot where the poor fellow had jumped ashore. It was made of great blocks placed one on the top of the other, so as to be a landmark perfectly visible while the eruptions of the volcano left it undisturbed. On one of the side stones, Bell chiselled the simple inscription-- JOHN HATTERAS. The duplicate of the document attesting the discovery of the North Pole was enclosed in a tinned iron cylinder, and deposited in the cairn, to remain as a silent witness among those desert rocks.