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of 1200 to 1500 feet would carry beneath the waters other valleys of the Himalaya, that are at an elevation of 4000 to 4500 feet. There would then remain south of the Himalaya only the Vindhyan range of mountains, running across the peninsula, north of the Nerbudda to the western coast, and the western and eastern Ghauts, the former of which rise from 6000 to near 9000 feet.* There would thus be five or six stages in the submersion, at which great changes would take place in the proportion of the land to the sea, and of the volume of land rising above the water. Equal variations also in the opposite direction would result from the emergence from the ocean of those parts of the supposed arctic continent, that would correspond to these divisions of Hindostan. It is physically impossible, therefore, that the changes he contemplates should take place without producing repeated and great variations in the average of the extent and the volumeof dry land, and of the depth of the sea, unless they were wrought with such rapidity that the time which they occupied should be of no consideration. But to be accomplished with such rapidity would require an intensity of volcanic forces immeasurably transcending those that are ordinarily exerted in the modification of the earth's surface. The effects also would boundlessly surpass in magni- * Macculloch's Geographical Dictionary; Articles Himalaya and Hindostan. Guyot's Earth and Man, p. 66.

tude any that are now in progress, or that have happened for many ages. Such a depression of one continent and elevation of another would produce movements of the ocean also, on a scale and of a violence immensely beyond those of ordinary disturbances of its bed by earthquakes. "Wide-spreading deluges, and the wreck of islands and continents generally, would inevitably result from them.

He thus in his hypothesis completely deserts the theory of the uniform force and activity of geological agents, on which he founds his system; and tacitly raises those of fire and water to so vast an energy, and exhibits them as acting on so stupendous a scale, and dispatching their effects with such celerity, as to discountenance and set aside the grounds on which he builds his inference, that long periods have been employed in the deposition and modification of the strata. Of this purely supposititious character are many of the other solutions which he presents of the phenomena he attempts to explain; and such are the speculations also generally of those who maintain that the stratified rocks were formed by the geological agents that are now in activity, and at a rate essentially the same as that at which they produced their present

* We may indicate as examples, their theories respecting the production of gneiss, the origin of lime and chalk, the formation of salt and coal, the causes of denudation, the sources of drift, the deposition of alluvia, the periods at which different classes of animals began to exist, and a crowd of others.

effects.* They are mere conjectures or suppositions, not demonstrated facts, and present, therefore, no basis for a scientific induction of the inference they found on them of the great age of the world.

QUESTIONS.

What is their second postulate which is examined in this chapter? Is it clear from what has already been shown, that rivers had no important agency in the formation of the strata? What then are the agents by which, according to the theory, the strata must have been formed? What is the first objection to the theory that the strata are the work of such causes in kind and energy as are now in activity on the earth's surface? Ought it not to be demonstrated, instead of gratuitously assumed? Have geologists verified it by proofs? What course does Sir C. Lyell pursue in regard to it? What is the only consideration which he offers to prove it? But what points ought he to establish, in order that that consideration may demonstrate that which he alleges it as proving? Does he establish that point, or does he take it for granted? State his argument in a syllogistic form: first, in which all changes are affirmed to be the effects of the same causes; and next, in which all causes are affirmed to act with the same energy. Is it clear from these that he assumes in his premise the whole point which he affects to prove? What is the question which he should have debated? What is the question which he in fact debates? Does he thus try the question by a false measure? Does he pursue this course generally in his attempts to account for particular effects? State his mode of explaining the changes in the temperature of the earth. Does he establish this by a scientific induction, or does he merely affirm, that if the conditions he supposes are admitted, then the results for which he contends would follow? Is it not wholly unphilosophical thus to substitute hypotheses for facts; assumptions for proof? Might not the theories of Buffon, Whiston, La Place, and the author of the Vestiges of Creation, be established by that process, as well as his theory of the changes for which he attempts to account? Does he not also desert in it the postulate on which he professedly proceeds, that the forces that are producing changes on the earth act uninterruptedly, and with the same energy? State the mistake into which he falls in the representation that if Hindostan with the Himalaya mountains were slowly to sink beneath the ocean, and a continent of equal dimensions, a similar general surface, and like mountains, were at the same time to rise at the same rate from the ocean between the Orkneys and Greenland, the quantity of land that would rise above the ocean would, at any stage of the process, precisely equal that which would descend beneath it. Exemplify the error of that assumption. If two pyramids of equal dimensions were to pass through such a change of positions, is it not clear that the twenty feet of the base of the pyramid that sunk beneath the water, while twenty feet of the apex of the other rose out of it, would comprise hundreds and thousands of times as many cubic feet as the apex comprised? Are many of the solutions of facts which geologists offer as confirmations of their theory, of the same supposititious character, and contradictory to their own principles?

CHAPTER XII.

False Theories of Geologists respecting the Formation of the Strata.

But this great postulate of their system is not only merely hypothetical and unsupported by evidence; it is confuted, and shown to be wholly groundless, by the fact that many of the most extensive and important of the geological effects which it professes to explain, are not now in the process of production, nor the causes to which they owed their existence any longer in activity. If the assumption were correct that the forces by which geological effects are produced are in the main at all periods identically the same, act uniformly with the same energy, and generate the changes to which they give birth at the same rate, then every class of effects that has ever resulted from their agency would continue to be wrought by them at the present time, and on a scale as vast as at any former period. Nothing, however, is more certain than that many of the most important species of those effects are no longer taking place, and thence that the causes in which they originated

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