The earth and its origin were much later than the heavens in becoming the object of scientific investigation. The numerous ancient and modern cosmogonies do, indeed, profess to give us as good an insight into the origin of the earth as into that of the heavens; but the mythological raiment, in which all alike are clothed, betrays their origin in poetic fancy. Among the countless legends of creation which we find in the history of religions and of thought there is one that soon took precedence of all the rest--the Mosaic story of creation as told in the first book of the Hexateuch. It did not exist in its present form until long after the death of Moses (probably not until eight hundred years afterwards); but its sources are much older, and are to be found for the most part in Assyrian, Babylonian, and Hindoo legends. This Hebrew legend of creation obtained its great influence through its adoption into the Christian faith and its consecration as the "Word of God." Greek philosophers had already, five hundred years before Christ, explained the natural origin of the earth in the same way as that of other cosmic bodies. Xenophanes of Colophon had even recognized the true character of the fossils which were afterwards to prove of such moment; the great painter, Leonardo da Vinci, of the fifteenth century, also explained the fossils as the petrified remains of animals which had lived in earlier periods of the earth's history. But the authority of the Bible, especially the myth of the deluge, prevented any further progress in this direction, and insured the triumph of the Mosaic legend until about the middle of the last century. It survives even at the present day among orthodox theologians. However, in the second half of the eighteenth century, scientific inquiry into the structure of the crust of the earth set to work independently of the Mosaic story, and it soon led to certain conclusions as to the origin of the earth. The founder of geology, Werner of Freiberg, thought that all the rocks were formed in water, while Voigt and Hutton (1788) rightly contended that only the stratified, fossil-bearing rocks had had an aquatic origin, and that the Vulcanic or Plutonic mountain ranges had been formed by the cooling down of molten matter.