“Then, after the Oligocene Epoch, the mountains of to-day began to rise. Through the Miocene and Pliocene Epochs, the Atlas Mountains, the Alps, the Pyrenees, the Apennines and the Caucasus rose above the plain, and the floor of the Eocene ocean is found to-day ten thousand feet above sea-level in the Alps, fifteen thousand feet above sea-level in the Himalayas, and twenty thousand feet above sea-level in Thibet. And, Perry, as the land rose at the end of the Pliocene Epoch, and the Pleistocene Epoch began, tropical beasts and plants fled to the Equator, snow gathered on the newly made mountain ranges, glaciers glittered on their flanks. The Third Ice Age had come, the beginning of the Quarternary or Modern Period. Nor is the Third Ice Age yet past, for it is only recently that the shrinking of the ice has allowed Man to stand on the North and South Poles of the globe.” “Perry!” suddenly rang out a cry, with a note of strident urgency, “get me my field-glass, quick!” Wondering, but realizing the note of haste in the command, the boy jumped into full stride along the deck and down the companion way. He was back in half a minute, taking the glass out of the case as he ran. Already the rail was crowded with figures, but they made way for him. He handed the field-glass breathlessly to the professor, and looked, with an intensity that made his eyes burn, in the direction whither the binocular was pointing. “It’s a boat,” he said, “a little boat; no, two boats; no, three—” He clutched his uncle’s arm. “Those aren’t boats—” he began, and stopped. About a quarter of a mile away, the even blue ripples of the great inland sea were broken by something black that seemed to be advancing on the ship, moving on a line that converged upon the vessel’s course. Excitement sent the boy’s heart thumping like the engines of the steamer, and when, a moment later, without a word, his uncle handed the glass to him, his hands shook so much that he could hardly focus the instrument. There leaped into view, in the field of the glass, a broad head, something like that of a seal, but poised upon a thick, long neck. He could have sworn there were long coils behind, but he could not see them. “The _Dædalus_—” he half panted. “My camera!” came a second crisp order. Perry handed back the glass, which the professor almost snatched from his grasp. If the boy had hurried the first time for the binocular, he made the decks burn on his second trip. He knew that the professor’s big camera would take valuable time to unpack, so he fairly raced along the stateroom corridors to his own cabin for his own small camera, and he thanked his lucky stars, as he ran, that he had put in a new roll of film that morning. He could not have gone faster, but, when he returned, his uncle was sweeping the horizon with the glass in a way that showed all too plainly that the object of search was no longer in view. “Gone!” he cried, in apprehension. “Yes,” said the professor, “gone!”