ing-place for man. But, during geologic ages unnumbered, the powers of water have been wrestling with the powers of fire. Rains and floods have been tearing down what fire had built. The energies of fire have been wasting; the earthquake and the volcano have been stricken with the palsy of age. Old Ocean, however, is still in his youth. The volcano had been smitten with decrepitude even before the ocean had its birth. The denuding and destroying agencies of Nature have gained the ascendency, and, in the inevitable order of things, are destined to retain it. Let us glance at the labors of water in leveling the inequalities which ancient volcanic energy had long ago created upon the surface of our planet. Throughout the whole extent of the circumambient sea, the tireless surge is gnawing at the rock-bound shore, and mouthful by mouthful the continents and the islands are being swallowed up. The sediment which every summer shower washes down the hill-side is so much material taken from the hill-top and deposited in the valley. The deep mould of the alluvial fiat is made up of the spoils of the adjacent declivities. By as much as the valley is raised, the hills are lowered. The turbid waters of a winter stream are hurrying off with a freight of sediment stolen from a hundred townships. The mud which settles in my glass of river water upon a Mississippi steam-boat is a mouthful of the Rocky Mountains-or perchance of the Alleghanies-or, what is still more probable, it is a whole museum of soils, gathered from the fertile farms of New York and Pennsylvania-from the sandy cliffs of the Great Kenawha-from the clayey slopes of Cincinnati—from the slimy borders of Lake Pepin-from the melon-patch of a Cheyenne squaw, and from the beetling cliffs of the far-off Yellowstone. Of what part of the country is not this slime the washing? From month to month, and from year to year, and from age to age, this stately river is floating off the land--not noisily, but sullenly and angrily, as if the waters had some great wrong to avenge upon the land. And all these filchings from the mountain and the plain are restored again to the sea. Old Ocean is receiving back his own. The rivers are his allies, and right faithfully do they forage to supply the cravings of his insatiate maw. We witness such work in progress during the brief moment of our tarry upon the earth. We look back along this line of operations, and discern for the first time the gigantic results which have already been achieved by the wearing agency of waters. Not during the lifetime of Adam's race alone, but during the age of quadrupeds which preceded him—through the dynasty of reptiles, still more ancient, have these denuding forces been ceaselessly engaged in scraping, and gouging, and scarring the face of Nature. River-beds have been deeply excavated and again obliterated by a plethora of rubbish poured forward by some more gigantic operation. Lake basins have been scooped out-Niagara gorges dug-square miles of land, with its underlying rocky floors, have been swept away. From the summits of the Catskill Mountains the Old Red Sandstone once stretched eastward perhaps to Massachusetts Bay. The powers of water have strewn it over Long Island Sound, and far to the seaward of Sandy Hook. The Cumberland Table-land once reached a hundred and fifty miles westward over the basin of Middle Tennessee. The site whereon the city of Nashville now stands was once a thousand feet beneath the level of the land. Half a state was scraped away to extend the borders of Mississippi and Alabama. The Alleghanies, in their prime, were three thousand feet higher than human eyes have ever seen them. Their ancient summits are sunken in the Atlantic and the Gulf of Mexico. The Great American Desert was once as through the fertile as the Valley of the Mississippi. A great river watered it for a thousand miles, while a hundred tributaries dispensed fertility throughout the region which was then the garden, as it is now the desert, of the continent. That fertile plateau has been drained to death. Each stream has drilled a frightful chasm deep rocky foundations of the plain (Fig. 96, 97). The mother stream, the Colorado, dwarfed to a withered mockery of what it was, now creeps along at the bottom of a narrow gorge whose rocky walls rise, in places, more than a mile in height. From the brink of this appalling chasm, three hundred miles in length, your vision struggles down six thousand feet into the realm of twilight; and in this prison the attenuated Colorado-patriarch of American rivers-is wasting its senile energies from year to year, but, with "the ruling passion strong in death," it is still carrying off the land, even though each season's work sinks it into a deeper grave. Such are the works of running streams and corroding waves. The record of their labors is the utterance of the destiny of the land. History inverted becomes prophecy. The doom of the mountains is engraven upon their rocky buttresses. Half the pride of the Alleghanies has already been removed. Rounded hill-top is dissolving into plain. Defiant granite, which buffeted the lightnings that rent Sinai, and frowned upon the flood that drowned "the world," shall yet be brought down by the multitudinous pelting of rain, and the insidious sapping of frost. The mountains shall be wiped off. The continents shall be worn out. The rivers will have dug their graves. The ocean will have eaten up the land; and all there was of the dwelling-place of man will be a rocky islet, a ragged bluff, a sunken reef--the crumbs that fell from old Ocean's meal. There was a time when, by degrees, the continents were slowly and steadily surging from the sea. The sea, robbed of half his dominions, has ever since been raging around the borders of the land. At last he will again reclaim his own, and the universal empire will be Neptune's. It is vain to hope that elevatory forces can permanently avert the disappearance of the land. We discover here. another argument against the vague belief entertained by some, that the human fauna is to be succeeded by a higher one, as it has itself succeeded the lower. Should it be supposed that the ultimate submergence predicted is sufficiently remote to permit the interposition of a superior race of intelligences, I recall to mind the evidences that the lands are wasting and deteriorating; the river-beds are deepening, and diminishing the sources of irrigation; and all the populated regions of the earth are slowly approaching the desert condition of that ancient continent drained. by the Colorado. Each continental surface in the geological succession is the exclusive gift to a single great fauna. A single race witnesses the disappearance of the freshness and fertility of the land. A new race would demand a thorough renovation, like that which immediately preceded the advent of man. Such a revolution the senescent forces are unable to inaugurate. WE CHAPTER XXXVII. THE REIGN OF UNIVERSAL WINTER. E open, now another volume of geological records. I have stated that the energies of the earth's internal fires are waning. There is a chain of effects which, when we trace them backward, conduct us to an ancient molten condition of the world. At a period comparatively recent, it was still so warm that tropical vegetation flourished within the arctic circle. At a remoter period, neither animal nor plant could endure the temperature which prevailed, nor the warfare which fire and water were waging with each other. We retain the solid monuments of a terrestrial condition which carries us still deeper into the heart of eternity; when the whole orb was a glowing ocean of incandescent lava, while yet the waters of the earth hung in invisible vapor upon the outskirts of the atmosphere, like a concealed foe meditating a secret attack upon a powerful enemy. Few who have studied the physics of the globe, and fewer still who have deciphered geological records, doubt that such were once the temperature and conditions of our planet. From that state to this, it has passed by the simple process of cooling. We trace the footsteps of this progress at every stage. Through Azoic, Eozoic, Paleozoic, Mesozoic, and Cenozoic Ages, heat has been gradually wasted in space-the solid crust has been thickening-the surface conditions have been changing. The average temperature of to-day, instead of being a state that is destined |