Thus it might indeed be possible still to discover some trace of an old-fashioned form in the existing planet; and a careful examination of the distribution of land and sea as represented on a terrestrial globe does, in fact, reveal a remarkable symmetry, in which we seem to recognise a surviving vestige of its early state. The great continent of Africa projects like the narrow end of a pear; around it are oceans--the Atlantic, the Indian Ocean, and the Mediterranean Sea, which was once of far greater extent; then comes a great dismembered ring of land, the two Americas, the Antarctic continent, Australia, Asia, and Europe. Within these, on the side opposite to Africa, is the great Pacific Ocean, which covers over the broad end of the pear. [Sidenote: Earth’s Unknown Changes] [Illustration: THE SHAPING OF THE FACE OF THE EARTH Soon after the earth had cooled down, so that the oceans were formed, the shaping of the great continents began. The action of moving water in the making of new land is well illustrated by the vast delta of the Mississippi, where an area larger than Wales has been formed by debris deposited by the river. ] A line drawn from somewhere in Central Africa to its antipodes in the Pacific, through the centre of the earth, would correspond to the long axis of the pear; a second, at right angles to this, would correspond to its breadth; and a third, at right angles to both, would correspond to the axis on which it rotates. A diameter of the earth taken through the equator is almost 8,000 miles in length, the Polar diameter is about sixteen miles shorter, and this slight difference measures the oblateness of the spheroid, or the departure of the form of the earth from a true sphere. Further, it would appear that the diameter drawn through Africa is about half a mile longer than the equatorial diameter taken at right angles to it, and this insignificant quantity measures the departure of the form of the earth from that of an oblate spheroid to that of a pear, so nearly complete is the adjustment of its form to existing conditions. Before this nice adjustment was reached, the earth must have suffered many changes, passed through many times of stress and storm, and witnessed many geological revolutions. [Sidenote: An Age of Red-hot Rain!] If, at the beginning of her career, the earth was molten, or at a very high temperature, she must have been surrounded by a very deep and dense atmosphere, for all the waters which now rest on her surface--oceans, lakes, and rivers--would have contributed to it in the state of steam; and not till the temperature of the ground had fallen to 380 deg. C. could liquid water have begun to accumulate. Then a steady downpour of almost red-hot rain would have set in, filling up the neck of the pear and extending far and wide over its broad end.