“No one knows, no one,” was the answer. “The largest outcrop of the oldest or Archæan rocks is in Canada, where the great Laurentian Range tells the story of the fire-made earth in its granite and gneiss deposits. All that had been deposited upon those rocks has been washed away and the old formation is laid bare. Then, as the land and seas cooled further, the hot steaming mists condensed the water that for so many millions of years had hung in clouds of vapor over the earth and torrential rains began to fall. Thus the huge shallow oceans spread over the globe, leaving very little land. This was the Cambrian Period, the oldest of the six divisions of the Paleozoic Era. You know what ‘paleozoic’ means, Perry?” “Sure,” answered the boy, “the oldest life.” “Right, right. Now, in the Cambrian Period, all the present Mediterranean was upheaved, part of an early continent that included all of Africa, Eastern Europe and Asia. Western Europe was a shallow sea. In the next Period, the Ordovician, there was a further change and leveling. The Atlantic reached as far as what is now Italy, while Greece and Asia Minor were its coast lands. Siberia was sea, then, Perry, and the Indian Ocean was land.” The lad passed his hand in a puzzled way across his forehead. “It’s hard enough to remember geography now,” he said, “but it would be fierce if a chap had to know all that ancient stuff as well!” Antoine laughed and swept his hand again across the clay. “You wouldn’t have to learn much geography around this part of the world during the next stage, the Silurian Period,” he said, “because it was all sea. But,” and his fingers modeled a plateau, “at the end of the Silurian Period the land rose again, and when all these changes were complete, two things had happened. Fish had evolved in the sea, and plants had appeared on the land. “Then,” he continued, “came the Devonian Period, when the Old Red Sandstone was laid down under the sea. Curiously enough, Perry, except for a small range of hills in Scotland and for parts of Norway, the only high land in Europe was the part that is now the bed of the Mediterranean Sea, the very land over which we are at present sailing,” and he pointed over the vessel’s side. “All through the Devonian Period and the next, that of the Coal Forests or the Carboniferous, the sea ate steadily into the land, the big Mediterranean island was cut in two, and nearly all the world became a dull, hot, dank marsh, with mosses a hundred feet high and huge horse-tails five feet in circumference. There were no seasons then, summer and winter were the same. There was no movement except the sluggish crawling of a giant salamander or the flight of a large primitive insect. Not a spot of color existed, not the song of a single bird. The Carboniferous Period ended with the whole of Europe one sinister and gloomy marsh, the giant vegetation of which became the coal we use to-day.”