PRE-GLACIAL MAN'S PICTURE OF REINDEER 350 PRE-GLACIAL MAN'S PICTURE OF THE HORSE 351 SPECIMEN OF PRE-GLACIAL CARVING 352 STONE IMAGE FOUND IN OHIO 353 COPPER COIN, FOUND ONE HUNDRED AND FOURTEEN FEET 356 UNDER GROUND, IN ILLINOIS {front} COPPER COIN, FOUND ONE HUNDRED AND FOURTEEN FEET 356 UNDER GROUND, IN ILLINOIS {back} BIELA'S COMET, SPLIT IN TWO 409 SECTION ON THE SCHUYLKILL 432 RAGNAROK: THE AGE OF FIRE AND GRAVEL. PART I. The Drift CHAPTER I. THE CHARACTERISTICS OF THE DRIFT. READER,--Let us reason together:-- What do we dwell on? The earth. What part of the earth? The latest formations, of course. We live upon the top of a mighty series of stratified rocks, laid down in the water of ancient seas and lakes, during incalculable ages, said, by geologists, to be from _ten to twenty miles in thickness_. Think of that! Rock piled over rock, from the primeval granite upward, to a height _four times greater than our highest mountains_, and every rock stratified like the leaves of a book; and every leaf containing the records of an intensely interesting history, illustrated with engravings, in the shape of fossils, of all forms of life, from the primordial cell up to the bones of man and his implements. But it is not with the pages of this sublime volume {p. 2} we have to deal in this book. It is with a vastly different but equally wonderful formation. Upon the top of the last of this series of stratified rocks we find THE DRIFT. What is it? Go out with me where yonder men are digging a well. Let us observe the material they are casting out. First they penetrate through a few inches or a foot or two of surface soil; then they enter a vast deposit of sand, gravel, and clay. It may be fifty, one hundred, five hundred, eight hundred feet, before they reach the stratified rocks on which this drift rests. It covers whole continents. It is our earth. It makes the basis of our soils; our railroads cut their way through it; our carriages drive over it; our cities are built upon it; our crops are derived from it; the water we drink percolates through it; on it we live, love, marry, raise children, think, dream, and die; and in the bosom of it we will be buried. Where did it come from? That is what I propose to discuss with you in this work,--if you will have the patience to follow me. So far as possible, [as I shall in all cases speak by the voices of others] I shall summon my witnesses that you may cross-examine them. I shall try, to the best of my ability, to buttress every opinion with adequate proofs. If I do not convince, I hope at least to interest you.