Page:Popular Science Monthly Volume 34.djvu/677

canic rocks should be altogether different in character from those of Tertiary and recent times. During the periods mentioned volcanic rocks appear, as we should expect, to have been ejected from beneath the earth's crust similar in composition and condition, and to have solidified with identical environment. Hence the results, allowing for secondary changes, should still be similar. But to assume that the environment of a rock in early Archæan times was identical with that of similar material at a much later period is to beg the whole question. My creed also is the uniformitarian, but this does not bind me to follow a formula into a position which is untenable. "The weakness and the logical defect of uniformitarianism" (these are Prof. Huxley's words) "is a refusal, or at least a reluctance, to look beyond the 'present order of things,' and the being content for all time to regard the oldest fossiliferous rocks as the ultima Thule of our science." Now, speaking for myself, I see no evidence since the time of these rocks, as at present known, of any very material difference in the condition of things on the earth's surface. The relations of sea and land, the climate of regions, have been altered; but because I decline to revel in extemporized catastrophes, and because I believe that in nature order has prevailed and law has ruled, am I therefore to stop my inquiries where life is no longer found, and we seem approaching the first-fruits of the creative power? Because palæontology is perforce silent; because the geologist can only say, "I know no more," must I close my ear to those who would turn the light of other sciences upon the dark places of our own, and meet their reasoning with the exclamation, "This is not written in the book of uniformity"? To do this would be to imitate the silversmiths of old, and silence the teacher by the cry, "Great is Diana of the Ephesians! "What, then, does the physicist tell us was the initial condition of this globe? I will not go into the vexed question of geological time, though, as a geologist, I must say that we have reason to complain of Sir W. Thomson. Years ago he reduced our credit at the bank of time to a hundred million years. We grumbled, but submitted, and endeavored to diminish our drafts. Now he has suddenly put up the shutters, and declared a dividend of less than four shillings in the pound. I trust some aggrieved shareholder will prosecute the manager. While personally I see little hope of arriving at a chronological scale for the age of this earth, I do not believe in its eternity. What, then, does the physicist tell us must have been in the beginning? I pass to the consistentior status of Leibnitz, when the molten globe had crusted over, and its present history began. Rigid uniformitarian though you may be, you can not deny that, when the very surface of the ground was at a temperature of at least 1,000° Fahr., there was no rain, save of glowing