When physical science shall be so far advanced as to explain the true causes of the earthquake, if it does not make man "master of the situation," it will doubtless place in his hands the power of avoiding, to some extent at least, the calamities which now so often befall life and property. There can be no doubt that the earth is a physical necessity not yet fully developed; only about one-fourth part of its surface is land, the remainder water. Nearly three times more land lies north of the equator than south of it. Why this should be so, is not quite clear. In the course of the earth's future development, however, it is not improbable that additional continents and islands will appear, and the waters subside into narrower and deeper channels, thus giving to man, and to land-life generally, a wider domain. And yet the present seas were not made in vain, but have always abounded with plant-life and animal-life, though of an inferior order as compared with land-life. Life in itself is infinite, and appears in infinite varieties both on land and in the sea. Whether man needs more land for his use and future development, is difficult to say. At any rate, everything that exists has its mutual relations, and adapts itself to the ultimate aim of Nature,--the perfection of man. In the Western Hemisphere, the mountains take the general direction of north and south; in the Eastern, the general direction of east and west. In the one hemisphere, the ranges essentially accord with the lines of longitude; in the other, with the lines of latitude. These mountain ranges are but continental watersheds, from which flows the elemental wealth that enriches the plains and the valleys. The rivers and their tributaries are the commercial agents. The rain and the frost are the miners whose labors will never cease until the mountains are levelled. The mountains also attract and guide the storms and modify their force, condense the mists, the raindrop, and the dewdrop, and thus aid in refreshing the valleys in connection with the heat of the sunbeams. In this way the seasons, as well as the elements of the soil, are so modified and vitalized as to give to man seedtime and harvest, and needful food to every "living and creeping thing."