Not only lakes and seas have disappeared, but whole continents, in much more peculiar ways. Where the Atlantic Ocean now lies, there was once, some four million years ago, a continent which we call “Atlantis,” connecting America with Africa, and believed to have been peopled with a race far more intelligent than any now existing upon the earth. They were one-eyed and had conquered the laws of nature; their airships flying by natural forces, such as do our sailboats. Their animals could speak and had great destructive powers. But this can be only hearsay, since now “Atlantis” lies at the bottom of the ocean, gone forever, like many mountains which have likewise gone down into the waters. These surface changes, together with internal disturbances, created a wandering polar system and bodily displacement of both poles took place. With this came a great change in the climate of the earth. The lands of the present equator, which, only some twenty thousand years ago, were as cold as our present arctic zones, became tropical in climate, while the flourishing lands at the north and south poles grew desolate and cold, as they are today. The pole-axis of the earth has since changed considerably--Europe, only some twelve thousand years ago being covered with a great ice sheet. The highest peak of the earth is Mount Everest, twenty-nine thousand feet above sea level, and the greatest depth of the sea is more than twenty-five thousand feet. Some of the earth’s surface lies below sea level, but it is not flooded on account of being surrounded by mountain ranges. A great part of the Sahara, for instance, is below sea level. The Sahara, less inhabited than any other area of the earth, covers one-twelfth part of the land surface of the earth, having an area of some four million square miles. It is by no means all sand; there are some plateaus and oases. In the days of Julius Caesar it was a fertile, well cultivated land, and was known as the “Granary of the Roman Empire.” With the fall of the old Roman Empire, however, the desert was neglected and the sands swallowed up the fertile lands. Scientists and explorers have dreamed for generations of schemes not only to cultivate the desert, but to put such fertile lands within the reach of industry. It is estimated that the Sahara could easily support a population of two hundred million souls and in addition supply Europe with all her fruit, vegetables, cereals and cotton, in fact with all products that are at present produced in North America. The government of France, some fifty years ago, wanted to build a fifty-mile canal and let the waters of the ocean flow in to submerge and flood a great part of the Sahara, so as to change the climate and produce vegetation. Such a plan, however, would not only change the climate of the Sahara, but would change the climates of all the countries of the entire world, with dire consequences, and to such an extent that the end of the world would be believed near.