"Higher, higher!" repeated the madman.
"Very well, we shall not allow it-that is all."
He had hardly uttered the words before Hatteras, by a superhuman effort, sprang over the boiling lava, and was beyond the reach of his companions.
A cry of horror burst from every lip, for they thought the poor captain must have perished in that fiery gulf; but there he was safe on the other side, accompanied by his faithful Duk, who would not leave him.
He speedily disappeared behind a curtain of smoke, and they heard his voice growing fainter in the distance, shouting-
"To the north! to the north! to the top of Mount Hatteras! Remember Mount Hatteras!"
All pursuit of him was out of the question; it was impossible to leap across the fiery torrent, and equally impossible to get round it. Altamont, indeed, was mad enough to make an attempt, and would certainly have lost his life if the others had not held him back by main force.
"Hatteras! Hatteras!" shouted the Doctor, but no response was heard save the faint bark of Duk.
At intervals, however, a glimpse of him could be caught through the clouds of smoke and showers of ashes. Sometimes his head, sometimes his arm appeared; then he was out of sight again, and a few minutes later was seen higher up clinging to the rocks. His size constantly decreased with the fantastic rapidity of objects rising upwards in the air. In half-an-hour he was only half his size.
The air was full of the deep rumbling noise of the volcano, and the mountain shook and trembled. From time to time a loud fail was heard behind, and the travellers would see some enormous rock rebounding from the heights to engulph itself in the polar basin below.