The Geological Theory of the Age of the Earth Examined.
By D. N. Lord
THE theory on which geologists found their inference of the great age of the earth is, that the materials of which the strata consist, were derived from mountains and continents of granite and other rocks; that those rocks were gradually disintegrated by the action of the air, water, and heat; that they were borne down from those mountains and continents by rains, currents, and rivers to the ocean, and distributed over its bed in successive layers; and that they were at length elevated from the bottom of the ocean to their present position; that the agents by which these vast effects were wrought, were those by which the somewhat similar changes that are now taking place, are produced; and that the number and thickness of the strata, the vast multitudes of vegetable and animal remains that lie buried in them, and the slowness with which similar processes of erosion and deposition now advance, prove that an immense series of ages must have been required for their formation. This inference of the age of the world, is thus founded on a theory of the sources from which the materials of the strata were derived, the agents by which they were transferred to the bottom of the ocean, and the forces by which they were raised to their present position;—not irrespective of that on the strata themselves. On the other hand, we reject their hypothesis respecting the derivation of the materials of the strata, and the mode in which they were distributed over the bed of the ocean, as a mere assumption, inconsistent with the laws of nature, and the facts of the strata, and subversive of itself; and thereby confute the inference they found on it of the great age of the world, as unproved and unscientific. The question then we are to debate is, not whether the strata that have been formed since the earth was created, are such in nature and number as geologists represent; nor whether such vegetable and animal relics lie entombed in them. These facts are indisputable, and are admitted as freely in our reasonings as in theirs. But the question between us is, whether their hypothesis respecting the formation of the strata is legitimate; and thence whether the conclusion which they found on that hypothesis respecting the age of the world, is just and authoritative. In order that the hypotheses and reasonings on which geologists build their inference of the age of the world, may be legitimate and fill the office which they assign them, they must possess, it will be admitted on all hands, certain characteristics, and be free from certain faults. 1. They must be consistent with—not contravene—the laws of nature. Geologists must not assume, for example, as a preparative for their hypothesis respecting the formation of the strata, that the world originally existed in a state that is incompatible with its present nature. Such as that it was created a gas or an assemblage of gases; that implies that there was an immensely greater amount of caloric in it originally than now belongs to it; which is wholly unauthorized and unscientific. Geologists have no right to assume that it was imbued originally with thousands and millions of times its present sum of heat, than they have to assume that it had thousands and millions of times its present bulk of water, air, quartz, lime, or any other ingredient that enters into its composition. It is against the great principle also, on which they proceed in their attempts to account for the changes which the surface of the earth has undergone: namely, that the effects that have been wrought in it, were the work of identically the agents—air, water, and heat,—that are now producing changes on the earth's surface, and acting on their present scale both of extent and of intensity. It is to contradict the laws of matter likewise, to assume that the world was created in the form of gas. Matter with the exception of a few species—such as the elements of air and water—is raised to a gaseous form only by intense heat. But heat is naturally latent. It is developed or made perceptible only by chemical action. To suppose the world to have been created in a gaseous form, is therefore to suppose it to have been created in a condition in which it could not—according to the present laws of matter—have existed, except as a secondary state; or as a consequence of the action of its elements on each other after they were created. That supposition therefore contradicts the laws of heat and the formation of gaseous bodies. It is as unphilosophical and absurd to suppose the matter of the globe to have been created in the form of a gas, as it is to suppose it was created in the form of vegetables and animals; organic structures which matter never assumes until after it has existed in another form. An inference of the great age of the world, founded on an assumption, on the one hand, of the creation of its matter in a state in which by its laws it could not exist, until after it had existed in another form; and on the other, of its originally containing a far larger share of one of its elements than now belongs to it, can have no claim to be regarded as legitimate and authoritative. 2. They must not assume as a basis of their inference of the age of the world, that it once existed in a form of which they have no proof; such as that it was in a state of fusion; and that a granite crust was formed over its molten ocean, by the cooling of its surface. Such a supposition is forbidden, indeed, by the consideration to which we have already referred; that it implies that the earth originally had a far greater proportion of combustible matter than now belongs to it; as at present is not—so far as can be judged,—a hundredth, and probably not a millionth part of the combustible matter in the globe, that would be requisite, if ignited, to reduce its whole mass to a state of fusion. On the assumption, however, that there is no lack of combustible matter in the earth for the fusion of all its substances; there yet, is no proof nor probability that it ever was in a state of universal fusion. It is as impossible to prove that it ever was in such a state, as it is to prove that it once existed in a gaseous form. To build an inference of the age of the world on such an assumption, is therefore to build it on an hypothesis, of what cannot be shown to have been a fact; and that is to build it on nothing, and render it wholly unscientific and worthless. 3. They must not found their inference of the age of the world, on the assumption of a condition of the globe, which if it is supposed to have existed, instead of contributing to the formation of the strata, would have made their construction impossible: such as the supposition that the materials of the strata, were drawn from mountains of granite, that were ten or fifteen miles above the level of the ocean. The strata of the earth are held by geologists, to be on an average, about ten miles in depth. To maintain therefore, that their materials were derived from continents and mountains of granite, is to imply that those granite continents and mountains,—even if they covered as large an area as the strata now occupy—were at least ten miles above the level of the ocean; and if the mountains from which it is represented the matter of the strata was chiefly drawn, were of but half, or two-thirds the extent of the strata that are supposed to have been formed from them, then they must have been elevated at least fourteen or fifteen miles above the level of the ocean. But mountains elevated to such an enormous height and extending over vast areas, could it never have been disintegrated by the action of the air, water, and heat. There would have been no air, except of the most attenuated kind, and no water at all probably at that elevation. On the supposition that vapors could have ascended to such a height, and fallen in the form of snow, they would forever have remained congealed. No heat could have been developed there, sufficient to dissolve them. No rivers therefore could have flown from them, and consequently no detritus could have been borne from them to the sea, to be distributed over its bottom, and form layers, like our present strata. The supposition of such mountains, as the source of the materials of the strata, defeats itself, and renders the inference from it of the great age of the earth, unscientific and absurd. 4. They must not assume that the effects for which they attempt to account, are the work of agents, that are wholly inadequate to produce them: such as that the torrents and great rivers which they represent as having borne the materials of the strata from mountains and continents, entered the ocean with a rush, as to diffuse the gravel, mud, and vegetable with which they were loaded, through all its waters, and cause their deposition in layers co-extensive with its bed. None of the present rivers of the globe enter the ocean with such an impulse. So far from it, the currents of all the principal rivers are greatly checked as they approach the sea, divided into numerous channels, and brought to a dead pause, at the distance usually of fifty to one hundred miles from the shore; and consequently the detritus with which they are charged, falls to the bottom within a narrow space. The great mass of the ocean is no more affected by them, than the continents are, that lie opposite to the points where the rivers enter it. To assign to the rivers therefore, or the tides and currents of the sea, the distribution of the materials of the strata, throughout their whole domain, is to ascribe to them an effect, that wholly transcends their power. 5. They must not found their inference of the age of the world on an hypothesis, respecting the mode in which the strata were formed, instead of the strata themselves. To found their inference of the age of the world on the hypothesis, for example, that the strata were formed by the agency of heat, air, and water, acting only on the scale, and with the intensity, with which they are now disintegrating rocks, and bearing their detritus to the sea—is to beg at the outset, the very point which they affect to prove. For if the strata were formed by no other agents, than those which are now acting on the land, and the sea, and their deposition proceeded at no more rapid rate, than similar strata are now forming at the bottom of the ocean, then of course, a vast series of ages must have passed before their construction could have been completed; but such a method of establishing the antiquity of the globe, has no title to be regarded as demonstrative or logical. Geologists must first prove by irrefragable evidence, that the strata were formed by the slow process, which the hypothesis represents, before they can make that mode of their formation, the ground of an inference of the vast age of the world. To assume that hundreds or thousands of years were necessary for the structure of any one of the layers, of which the strata consist; and that therefore, as many hundreds or thousands of years were consumed in the construction of the whole, as there are layers in the whole of the strata—is to take for granted—not to prove the vast antiquity of the earth. 6. They must not assume any condition of the world, the existence of any agents, or the occurrence of any events, the reality of which they cannot demonstrate; and all their assumptions and reasonings must be consistent with all the facts, and all the laws of nature, which the question affects. To these axioms, geologists themselves will undoubtedly assent; and it results from them, that if the strata demonstrate that the world has subsisted through a vast series of ages, it must be by what they themselves are, in composition, bulk, and number—not by any theory of an antecedent state of the earth, or the processes by which they were formed. If they do not prove the great age of the world, by what they themselves are, irrespective of any speculations, in regard to the agents by which they were formed, they cannot prove it at all; precisely as, if the nature and number of the elements of which the great pyramid of Egypt consists, and the fact that it was erected by human hands—do not prove that millions of ages were occupied in its erection; no theory, respecting the agents by whom it was built, and the method of their procedure, can demonstrate, that such a period was occupied in its construction.—Geognosy, by D. N. Lord.