Now, this is clear, distinct statement; and nothing can be more evident than that the theologian who makes it holds he is reasoning with conclusive effect in behalf of what may be termed the short chronology,—not in its legitimate connection with the recent introduction of the human species, but in its supposed bearing on the age of the earth. And in doing so he commits himself to the apparent positive fact, determined on what may be regarded as geologic data, that the river Nile has been flowing over its bed for about as many years as have elapsed, according to the Hebrew chronology adopted by Usher, since the creation of man, and no more. To the integrity of this inference he pledges himself, as an inference to which the infidel ought to have yielded, as conclusive in its bearing on the question of the earth's age, and as of singular value to the believer who sets himself to deal with the evidences of his faith. Now, without referring to the circumstance that the data on which the French savans under Napoleon founded have since been challenged by geologists, such as Lieutenant Newbold and Sir G. Wilkinson, who have carefully surveyed the rocks and soils of Egypt with the assistance of clearer light than existed at the commencement of the century, let us, for the argument's sake, hold the inference to be quite as good as this theologian regards it. And see, we urge upon him, that you yourself do not suffer it to drop should you find that it commits you to the other side of the argument. Be at least as fair and honest as you say the infidels ought to have been. The six and a half metres of silt and slime,—representative, let us hold, of from five to six thousand years,—rest, you say, on "a foundation of sand like that of the adjacent desert." But have you ascertained on what the sand rests? I know nothing of that, replies the theologian; I had not even thought of that. But the geologist has thought of it, we reply; and has spent much time under the hot sun in ascertaining the point. For nearly three hundred miles,—from the inner boundaries of the delta to within a few hours' journey of the cataracts,—the silt and sand rest on what is known as the "marine" or nummulitic limestone,—a formation of great extent, for it runs into the Nubian desert on the one hand, and into the Libyan desert on the other; and which, though it abounds in the animalcules of the European chalk, is held to belong, in at least its upper beds, which are charged with nummulites, to the earlier Eocene. Over this marine limestone there rests a newer formation, of later Tertiary age, which contains the casts of sea shells, and whole forests of dicotyledonous trees, converted into a flint-like chert; and over all repose the sands and gravels of the desert. Underneath the silt of the river, then, and the sand of the desert, lie these two formations of the Tertiary division. The lower, which is of great thickness, must have been of slow formation. It is composed almost exclusively, in many parts, of microscopic animals, and abounds in others in fossil shells,—nautili, ostreadæ, turritella, and nummulites, with corals, sponges, the remains of crustacea, and the teeth of fishes. And between the period of its deposition and that of the formation which rests upon it the surface of what is now Egypt must have been elevated over the surface of the sea, to be covered, in the course of ages, by great forests, which, ere the land assumed its present form and level, were submerged by another oscillation of the surface, and petrified amid beds of a siliceous sand at the bottom of the ocean. Nor is the underlying marine limestone by any means the oldest of the sedimentary rocks of Egypt. It rests on a sandstone of Permian or Triassic age; the sandstone rests, in turn, on the famous Breccia de Verde of Egypt; and the Breccia on a group of Azoic rocks, gneisses, quartzes, mica schists, and clay slates, that wrap round the granitic nucleus of Syene. The formations of Egypt constitute a well-determined part of that great series of systems which compose the upper portion of the earth's crust: its silt is by far the most inconsiderable of its deposits; and if five thousand six hundred and fifty years were exhausted in laying down layer after layer of the twenty feet which form its average thickness, what enormous periods must we not demand in addition for the laying down of the forest formation, of the marine limestone formation, of the New Red Sandstone formation, of the Breccia de Verde formation, and, in short, for the some ten miles of fossiliferous rock of which those deposits form such definite, well-determined portions; besides the time necessary for the production of the enormously developed Azoic rocks which lie under all! The theologian, in this instance, instead of reasoning, as he himself supposed, in behalf of the short chronology, has been making out a very formidable case for the long one; and all that the geologist can have to urge upon him in the circumstances is simply that he should act as he holds the infidel ought to have done, and yield to the force of evidence. I may mention in the passing, that some of the most ancient buildings of Egypt are formed of the Tertiary marine limestones of the country; the stones of the pyramids are charged with nummulites, known to the Arabs as "Pharaoh's beans;" and these organisms stand out in high relief on the weathered portions of the Great Sphinx. Some of the oldest things in the world in their relation to human history,—erections, many of which had survived the memory of their founders even in the days of Herodotus,—are formed of materials so modern in their relation to the geologic epochs, that they had no existence as rock until after the Palæozoic and Secondary ages had gone by. Not only the Carboniferous sandstone of the High Church and Parliament House of Edinburgh, but even the Oolitic (that is, Portland stone) of Somerset House and St. Paul's, are of an antiquity incalculably vast compared with the stone out of which the oldest of the pyramids were fashioned.
NUMMULITES LÆVIGATA.
(Pharaoh's Beans.)
The second example which I shall adduce is one with which many of my auditors must be already familiar. The Falls of Niagara are gradually eating their way through an elevated tract of table-land, upwards towards Lake Erie, at the rate of about fifty yards in forty years; and it has been argued by Sir Charles Lyell, that as they are now seven miles distant from Queenston, where the elevation of the plateaux begins, they must have taken about ten thousand years to scoop out their present deep channel through that space.[43] Ten thousand years ago the Falls were, he infers, at Queenston; and the grounds on which he reasons are exactly those on which one would infer that a laborer who had cut a ditch two hundred yards long at the rate of ten yards per day, and was still at work without pause or intermission, had begun to cut it just twenty days previous. A reverend anti-geologist takes up Sir Charles;[44] and, after denouncing the calculation as "a stab at the Christian religion," seeing it involves the assertion that the "Falls were actually at Queenston four thousand years before the creation of the world according to Moses," he brings certain facts, adduced both by other writers and Sir Charles himself, to bear on the calculation, such as the fact that the deep trench through which the Niagara runs is much narrower in its lower than in its upper reaches, and that the river must have performed its work of excavation, when the breadth was less, at a greatly quicker rate than now. And thus the work of excavating the trench is brought fairly within six thousand years. Nor is the principle of the reasoning bad. In our illustration of the ditch excavated by the laborer we of course take it for granted that it is a ditch of the same depth and breadth throughout, and excavated in the same sort of soil; for if greatly narrower and shallower at one place than at another, or dug in a greatly softer mould, the rate of its excavation at different times might be very different indeed, and the general calculation widely erroneous, if based on the ratio of progress when it went on most slowly, taken as an average ratio for the whole. But the anti-geologist provokes only a smile when, in his triumph, he exultingly exclaims, "It is on grounds such as these that the most learned and voluminous among English geologists disputes the Mosaic history of the Creation and Deluge,—a strong proof that even men of argument on other subjects often reason in the most childish and ridiculous manner, and on grounds totally false, when they undertake to deny the truth of the Holy Scriptures." Now, it must be wholly unnecessary to remark here, that it is surely one thing to "undertake to deny the truth of the Holy Scriptures," and quite another and different thing to hold that the Niagara Falls may have been at Queenston ten thousand years ago; or further, that it seems not in the least wise to stake the truth of Revelation on any such issue. Let me request you, however, to observe, that in one important respect this writer resembles the former one. The former, ignorant of the various phenomena exhibited by the great deposits of Egypt, exhausted all his five thousand six hundred years of available time in accounting for the formation of one of the least of them,—the silt of the Nile; and the latter, though he bids down Sir Charles some four thousand four hundred years or so in the one item of scooping out the bed of the St. Lawrence, at least expends the remainder of the ten thousand,—his five thousand six hundred years,—in that work of excavation alone, and leaves himself no further sums to set off against the various geologic processes that may have preceded it.
In this case, as in the other, let us grant, for the argument's sake, all the facts. Let us admit that the trench through which the St. Lawrence now flows has been cut by the river in somewhat less than six thousand years. But through what, let us ask, has it been cut? There can exist no doubt on the subject: it has been cut through an ancient graveyard of the Upper Silurian system, charged with the peculiar fossils characteristic of what are known as the Clinton and Niagara groups, and common, many of them, to the Upper Silurian of our own country and of the European continent. Leptæna depressa and Pentamerus oblongus, two of the most frequent shells of the deposit, occur also in equal abundance in the Dudley and Caradoc formations of England; its prevailing encrinite, Ichthyocrinus lævis, is scarce distinguishable from an encrinite which I have often picked up in the quarries of the "Wren's Nest" (Ichthyocrinus pyriformis); while its prevailing trilobite, Phacops limulurus, seems to be but a transatlantic variety of our well known Asaphus (Phacops) caudatus. Further, the sequence of the various formations both above and below the Niagara group, is shown with remarkable distinctness in that part of the world along the shores of the great lakes. They may be traced downward, on the one hand, along the Lower Silurian deposits, to the non-fossiliferous base on which the system rests, and upwards, on the other, through the Old Red Sandstone and the Carboniferous Limestone, to the workable Coal Measures. Both stratigraphically and palæontologically the place in the scale of the Niagara graveyard can be definitely determined; and a superficial deposit on the heights in its immediate neighborhood shows that the river did not begin its work of excavation among its long extinct shells, trilobites, and corals, until after not only the great Palæozoic, but also the Secondary and Tertiary divisions had been laid down, and the recent period ushered in. The superficial shells of the adjacent heights belong to the Pleistocene age, and show that in even that comparatively modern time the lower lands of Upper Canada were submerged beneath the level of the ocean, and that a series of deep seas, connected by broad sounds, occupied the place of the great lakes. Not until the last upheaval of the land was the river now known as the St. Lawrence called into existence, to begin its work of excavation; and ere that event took place, fully ten miles of fossiliferous rock had been deposited on the earth's surface, charged with the remains of many succeeding creations. The deposit through which the St. Lawrence is slowly mining its way is older than the river itself by the vast breadth of the four Tertiary periods, by that of all the Secondary ages,—Cretaceous, Oolitic, and Triassic,—by the periods, too, of the Permian system, of the Carboniferous system, of the Old Red system, and of the uppermost beds of the Upper Silurian system. But a simple illustration may better serve to show the true character of the conclusion urged here by the opponent of Sir Charles, than any such line of statement as that which I employ, however clear to the geologist. In the year 1817, Prince's Street, in Edinburgh, was opened up to the Calton Hill, and the Calton burying-ground cut through to the depth of many feet by the roadway. Let us suppose that when the excavation has been carried a hundred yards into the cemetery, a geologist, finding the laborers cutting on the average about a yard per day, simply intimates as his opinion that the laborers have been a hundred days at work. "No," replies a controversialist on the anti-geological side; "for the first fifty yards, so soft was the subsoil, and so shallow the covering of mould, that the laborers must have cut at the rate of two yards a day; it has been merely for the last fifty yards that they have been excavating at the present slow rate: they cannot have been more than seventy-five days at work. I marvel exceedingly at the absurdity of geological reasoners: palpably the burying-ground of the Calton is only seventy-five days old." Now, such, in no exaggerated, but, on the contrary, greatly modified form, is the argument that would limit the age of the earth to the period during which the St. Lawrence has been scooping out a channel for itself, from Queenston to Niagara, through an ancient Silurian burying-ground. Both arguments alike confound the age of the ancient burying-grounds with the date of the modern excavations opened up through them; but in order to render the argument of my illustration equally absurd with the other, it would be not only necessary to infer that the Calton cemetery was only seventy-five days old, but also that the rock on which it rested was no older.
But enough of follies such as these! I had marked a good many other passages of similar character in the writings of the recent anti-geologists, and would have little difficulty in filling a volume with such; but it would be a useless, though mayhap curious work, and is much better exhibited by specimen than as a whole. A little folly is amusing, but much of it fatigues. There is a time coming, and now not very distant, when the vagaries of the anti-geologists will be as obsolete as those of the geographers of Salamanca, or as those of the astronomers who upheld the orthodoxy of Ptolemy against Galileo and Newton; and when they will be regarded as a sort of curious fossils, very monstrous and bizarre, and altogether of an extinct type, but which had once not only life, but were formidable. It will then be seen by all what a noble vestibule the old geologic ages form to that human period in which moral responsibility first began upon earth, and a creature destined to immortality anticipated an eternal hereafter. There is always much of the mean and the little in the worlds which man creates for himself, and in the history which he gives them. Of all the abortions of the middle ages which have come down to us, I know not a more miserable one,—at once ludicrous and sad,—than that heavens and earth of Cosmas Indicopleustes, the monk, which I illustrated by diagrams in my last lecture ([Figs. 114], [115]). They are just such heavens and earth as a monk might have made, and made too at a sitting. The heavens, represented as a solid arch raised on tall walls, resemble, as a whole, the arch which figures in the middle of a freemason's apron, or, more homely still, the section of a wine cellar; while the earth lies beneath as a great plain or floor, with a huge hill in the distance, behind which the sun passes when it is night. And yet this scheme gave law to the world for more than six centuries, and lay like a nightmare on physical discovery, astronomic and geographical. The anti-geologists have been less mischievous, for they live in a more enlightened age; and we already see but the straggling remains of the body, and know that the time cannot be far distant when it will be as completely extinct as any of the old faunas. The great globe, ever revolving on itself, and journeying in space round the sun, in obedience to laws which it immortalized a Newton to discover and demonstrate, is an infinitely more sublime and noble object than the earth of Cosmas the monk, with its conical mountain and its crypt-like firmament; nor can I doubt that its history throughout the long geologic ages,—its strange story of successive creations, each placed in advance of that which had gone before, and its succeeding organisms, vegetable and animal, ranged according to their appearance in time, on principles which our profounder students of natural science have but of late determined,—will be found in an equal degree more worthy of its Divine Author than that which would huddle the whole into a few literal days, and convert the incalculably ancient universe which we inhabit into a hastily run-up erection of yesterday.