Now, these results are no longer to be regarded as the dreams of fancy, but the legitimate deductions from long and careful observation of facts. And can any reasonable man conceive how such changes can have taken place since the six days of creation, or within the last six thousand years? In order to reconcile them with such a supposition, we must admit of hypotheses and absurdities more wild and extravagant than have ever been charged upon geology. But admit of a long period between the first creative act and the six days, and all difficulties vanish.
In the eighth place, the denudations and erosions that have taken place on the earth’s surface indicate a far higher antiquity to the globe, even since it assumed essentially its present condition, than the common interpretation of Genesis admits. The geologist can prove that in many cases the rocks have been worn away, by the slow action of the ocean, more than two miles in depth in some regions, and those very wide; as in South Wales, in England. As the continents rose from the ocean, the slow drainage by the rivers has excavated numerous long and deep gorges, requiring periods incalculably extended.
I do not wonder that, when the sceptic stands upon the banks of Niagara River, and sees how obviously the splendid cataract has worn out the deep gorge extending to Lake Ontario, he should feel that there is a standing proof that the common opinion, as to the age of the world, cannot be true; and hence be led to discard the Bible, if he supposes that to be a true interpretation.
But the Niagara gorge is only one among a multitude of examples of erosion that might be quoted; and some of them far more striking to a geologist. On Oak Orchard Creek, and the Genesee River, between Rochester and Lake Ontario, are similar erosions, seven miles long. On the latter river, south of Rochester, we find a cut from Mount Morris to Portage, sometimes four hundred feet deep. On many of our south-western rivers we have what are called canons, or gorges, often two hundred and fifty feet deep, and several miles long. Near the source of Missouri River are what are called the Gates of the Rocky Mountains, where there is a gorge six miles long and twelve hundred feet deep. Similar cuts occur on the Columbia River, hundreds of feet deep, through the hard trap rock, for hundreds of miles, between the American Falls and the Dalles. At St. Anthony’s Falls, on the Mississippi, that river has worn a passage in limestone seven miles long, which distance the cataract has receded. On the Potomac, ten miles west of Washington, the Great Falls have worn back a passage sixty to sixty-five feet deep, four miles, continuously—a greater work, considering the nature of the rock, than has been done by the Niagara. The passage for the Hudson, through the highlands, is probably an example of river erosion; as is also that of the Connecticut at Brattleboro’ and Bellows Falls. In these places, it can be proved that the river was once at least seven hundred feet above its present bed. On the Deerfield River, a tributary of the Connecticut, we have a gulf called the Ghor, eight miles long and several hundred feet deep, cut crosswise through the mica slate and gneiss by the stream.
On the eastern continent I might quote a multitude of analogous cases. There is, for instance, the Wady el Jeib, in soft limestone, within the Wady Arabah, south of the Dead Sea. The defile is one hundred and fifty feet deep, half a mile wide, and forty miles long. In Mount Lebanon, several remarkable chasms in limestone have been described by American missionaries, as that on Dog River, (Lycus of the ancients,) six miles long, seventy or eighty feet deep, and from one hundred and twenty to one hundred and sixty feet wide; also, Wady Barida, whose walls are six hundred to eight hundred feet high. On the River Ravendoor, in Kurdistan, is a gorge, described in a letter from Dr. Perkins, one thousand feet deep. Another on the Euphrates, near Diadeen, is seventy feet deep, and is spanned by a natural bridge one hundred feet long. On the River Terek, in the Dariel Caucasus, is a pass one hundred and twenty miles long, whose walls rise from one thousand to three thousand feet high. In Africa, the River Zaire has cut a passage, forty miles long, through mica slate, quartz, and syenite; and in New South Wales, Cox River passes through a gorge twenty-two hundred yards wide and eight hundred feet high.
Ninthly. Since the geological period now passing commenced, called the alluvial, or pleistocene period, certain changes have been going on, which indicate a very great antiquity to the drift period, which was the commencement of the alluvial period, and has been considered among the most recent of geological events. I refer to the formation of deltas and of terraces.
Of the deltas I will mention but a single example, to which, however, many others correspond. The Mississippi carries down to its mouth 28,188,803,892 cubic feet of sediment yearly, which it deposits; or one cubic mile in five years and eighty-one days. Now, as the whole delta contains twenty-seven hundred and twenty cubic miles, it must have required fourteen thousand two hundred and four years to form it in this manner.
Terraces occur along some of the rivers of our country from four hundred to five hundred feet above their present beds, and around our lakes to the height of nearly one thousand feet. They are composed of gravel, sand, clay, and loam, that have been comminuted, and sorted, and deposited, by water chiefly. At a height two or three times greater, on the same rivers and lakes, we find what seem to be ancient sea beaches, of the same materials, deposited earlier, and less comminuted. The same facts also occur in Europe, and probably in Asia.
Now, it seems quite certain, that these beaches and terraces were formed as the continents were being drained of the waters of the ocean, and the rivers were cutting down their beds; which last process has been going on in many places to the present day. Yet scarcely nowhere, since the memory of man, have even the lowest of these terraces and beaches been formed, save on a very limited scale, and of a few feet in height. The lowest of them have been the sites of towns and cities, ever since the settlement of our country, and on the eastern continent much longer. Yet we see the processes by which they have been formed now in operation; but they have scarcely made any progress during the period of human history. How vast the period, then, since the work was first commenced! Yet even its commencement seems to have been no farther back than the drift epoch, since that deposit lies beneath the terraces. But the drift period was comparatively a very recent one on the geological scale. How do such facts impress us with the vast duration of the globe since the first series of changes commenced!
Finally. There is no little reason to believe that, previous to the formation of the stratified rocks, the earth passed through changes that required vast periods of time, by which it was gradually brought into a habitable state. It is even believed that one of its earliest conditions was that of vapor; that, gradually condensing, it became a melted globe of fire, and then, as it gradually cooled, a crust formed over its surface; and so at last it became habitable. All this is indeed hypothesis; and, therefore, I do not place it in the same rank as the other proofs of the earth’s antiquity, already adduced. Still this hypothesis has so much evidence in its favor, that not a few of the ablest and most cautious philosophers of the present day have adopted it. And if it be indeed true, it throws back the creation of the universe to a period remote beyond calculation or conception.