With such specimens before us of the miscalculations of the smaller periods by geologists, we are not surprised to find that they grossly exaggerate the larger cycles of time. The necessities of the evolution of the ascidian into the snail, of the snail into the fish, and of the fish into the lizard, of the lizard into the monkey, and of the monkey into the man, by slow and imperceptible changes, demanded an almost infinite length of time; and the geologists of that school accordingly asserted the existence of animal life upon our globe for hundreds of thousands of millions of years.
But Sir Wm. Thompson, one of the first mathematicians, demonstrates[371] the impossibility of any such length of time being spent in the process of cooling our little globe. Beginning with their own assumption, of a globe of molten granite cooling down to the present state, he proves that the earth can not have been in existence longer than a hundred millions of years; and of course that plants and animals have existed on it a much shorter time; as for the greater part of that period it was too hot for them. The geologists are now becoming ashamed of their poetical cycles, and some acknowledge that their chiefs blundered egregiously in their calculations.
The principles of geology seem to be as unsettled as its facts. There is no agreement upon any of its theories. The history of its theories, like that of their framers, begins with their birth, and ends with their burial. Each new theory placed the tombstone upon the preceding, and inscribed it with the brief record of the antediluvian, "and he died." A busy time they must have had with their Wernerian, Huttonian, and Diluvian hypotheses; not to mention the Hutchinsonian theory, the animal spirits flowing from the sun, the vegetative power of stories, and other sage and serious facts and theories, theological and philosophical, invented to account for the world's creation. "No theory," says Lyell, "could be so far-fetched or fantastical as not to attract some followers, provided it fell in with the popular notion." "Some of the most extravagant systems were invented or controverted by men of acknowledged talent." A more amusing exhibition of philosophical absurdity can not be found than those chapters which he devotes to "The Historical Progress of Geology,"[372] unless perhaps the scientific discussions of the erudite acquaintances of Lemuel Gulliver.
Let it not be supposed that the progress of inductive science, and the prevalence of the Baconian philosophy have banished absurdities and contradictions from the sphere of geology. It would require a man of considerable learning to find three geologists agreed, either in their facts, or in their theories. In a general way, indeed, we have the Catastrophists, with Hugh Miller, overwhelming the earth with dire convulsions in the geological eras, and upheaving the more conservative Lyell and the Progressionists; who affirm that all things continue as they were from the beginning of the world. And there is perhaps a general agreement now that the underlying primitive rocks, so called, are not primitive at all, as geologists thought twenty years ago; but, like the foundations of a Chicago house, have been put in long after the building was finished and occupied. But then comes the question how they were inserted—whether as Elie de Beaumont thinks, the mountains were upheaved by starts, lever fashion, or, as Lyell affirms, very gradually, and imperceptibly, like the elevation of a brick house by screws.[373] Nor is there the least likelihood of any future agreement among them; inasmuch as they can not agree either as to the thickness of the earth's solid crust which is to be lifted, or the force by which it is to be done? Hopkins proves by astronomical observation that it is eight hundred miles thick. Lyell affirms that at twenty-four miles deep there can be no solid crust, for the temperature of the earth increases one degree for every forty-five feet, and at that depth the heat is great enough to melt iron and almost every known substance. But then there is a difference between philosophers about this last test of solidity—those who believe in Wedgewood's Pyrometer, which was the infallible standard twenty years ago, asserting that the heat of melted iron is 21,000° Fahrenheit; while Professor Daniells demonstrates by another infallible instrument that it is only 2,786° Fahrenheit;[374] which is rather a difference. In one case the earth's crust would be over two hundred miles thick, in the other twenty-four. But then comes the great question, What is below the granite? and a very important one for any theory of the earth. It evidently underlies the whole foundation of speculative geology, whether we assume with De Beaumont and Humboldt, that "the whole globe, with the exception of a thin envelope, much thinner in proportion than the shell of an egg, is a fused mass, kept fluid by heat—a heat of 450,000° Fahrenheit, at the center, Cordier calculates—but constantly cooling, and contracting its dimensions;" and occasionally cracking and falling in, and "squeezing upward large portions of the mass;" "thus producing those folds or wrinkles which we call mountain chains;" or, with Davy and Lyell, that the heat of such a boiling ocean below would melt the solid crust, like ice from the surface of boiling water—and with it the whole theory of the primeval existence of the earth in a state of igneous fusion, its gradual cooling down into continents and mountains of granite, the gradual abrasion of the granite into the mud and sand which formed the stratified rocks, and all the other brilliant hypotheses which have sparked out of this great internal fire. Instead of an original central heat he supposes that "we may perhaps refer the heat of the interior to chemical changes constantly going on in the earth's crust."[375] Now if the very foundations of the science are in such a state of fusion, and floating on a perhaps, would it not be wise to allow them to solidify a little before a man risks the salvation of his soul upon them?
The various theories are contradictions. The igneous theory assault the aqueous theory with the greatest heat; while the aqueous theorists pour cold water, in torrents, upon the igneous men. The shocks of conflicting glacier theories have shaken the Alps and convulsed all North America; and have not yet ceased. There are eleven theories of earthquakes, which have been, and are still, such energetic agents in geology; and the whole eleven afford not the least rational idea of their causes; nor of any means of preventing, predicting, or escaping their ravages. The best geologists have described fossil tracks as the footprints of gigantic birds, which others equally as authoritative pronounce the tracks of frogs and lizards. Indeed, a good part of every geological treatise, and of the time of every association of geologists, is taken up with refutations of the errors of their predecessors.
There are no less than nine theories of the causes of the elevation of mountains; some scoop out the valleys by water; others by ice; others heave up the mountains by fire; and some by the chemical expansion of their rocks; while others still upheave them by the pressure of molten lava from beneath; and others again make them out to be the wrinkles of the contraction of the supposed crust of the liquid interior. Of all these theories an able geologist says: "The many proposed theories of mountain elevation are based upon assumptions which unfortunately are not true; but that is an unimportant matter to the majority of our speculating geologists; and one never seen by the inventors of the theories, who allow themselves to be led captive by a poetic imagination, instead of building their inductions upon field observations.
"Thus, to suppose that mountains are elevated by a wedge like intrusion of melted matter is to give to a fluid functions incompatible with its dynamic properties. So also the supposition that the igneous rocks were intruded, as solid wedges separating and lifting the crust, is opposed to the fact that no apparent abrasion, but generally the closest adhesion, exists at the line of contact of the igneous and stratified rocks. Equally fatal objections may be advanced against the other theories."[376]
Multitudes of the alleged facts of Infidel geologists are as apocryphal as their theories. Thus in a recent ponderous quarto volume, the production of half a dozen philosophers, this identical impossible theory—of the cooling of the earth's crust down to solidity, while an irresistible central heat remains below—is presented to the world as an ascertained fact; we are informed of the discovery of a human skull fifty-seven thousand years old, in good preservation; asked to believe that two tiers of cypress snags could not be deposited in the delta of the Mississippi in less than eleven thousand four hundred years; and to calculate that the delta of the Nile must have been a great many ages in growing to its present size, because it is quite certain that for the last three thousand years it has never grown at all.[377]
It were easy to fill a volume with such mistakes of geologists, but my limits restrict me to a few specimens. Silliman's Journal, in a review of "The Geology of North America, by Julius Marcoe, U. S. Geologist, and Professor of Geology in the Federal Polytechnic School of Switzerland; quarto, with maps and plates," says:
"The author describes the mountain systems of north America as he supposes they must be, according to the theoretical views of Elie de Beaumont." "Thus one single fossil—that one a species of pine, and only very much resembling the Pinites Fleurotti of Dr. Monguett—establishes a connection between the New Red of France, and that of America. This is a very strong word for a geologist to use on evidence so small, and so uncertain, with the fate of four thousand or five thousand feet of rock at stake, and the beds beneath, containing 'perhaps Belemnites.' The prudent observer would have said, establishes nothing; and such is the fact." "On such evidence a region over the Rocky Mountains, which is one thousand miles from north to south, and eight hundred miles from east to west, is for the most part colored in the maps as Triassic. Such a region would take in quite a respectable part of the continent of Europe." "We now know beyond any reasonable doubt, that all the country from the Platte to the British Possessions, and from the Mississippi to the Black Hills, is occupied by Cretaceous and Tertiary rocks. And as regards the region from the Platte southward to the Red River, very far the largest part is known to be not Triassic, while it is possible the Trias may occur in some parts of it." "It is unfortunate in its bearing on the progress of geological science to have false views about some five hundred thousand miles of territory, and much more besides, spread widely abroad through respectable journals, and transactions of distinguished European Societies."[378]