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is assigned them. To admit that no vestiges of them remain, and that there are no means even of determining where they were stationed, is to admit that the induction that is founded on them is supposititious also and without authority. This branch of their scheme is thus inconsistent also with the principles of geology, which prohibit the assumption of any condition of the earth as a basis of induction, which cannot be proved to have truly existed.

Let us, however, suppose that precisely such continents as they contemplate were in existence, and situated in positions the most favorable for the office they assign them; and in place of relieving their theory from embarrassment, it only renders its error more apparent.

The average elevation of the present continents and islands above the ocean is but a few hundred feet. Lake Superior is estimated to be about six hundred and forty feet only above that level. Were all those portions therefore of the mountains and high lands of the continent north of the equator that are above the surface of that lake, removed and spread over those parts that are below it, they would undoubtedly be altogether inadequate to raise them to the same height above the sea. On the other hand, the strata of the continents are estimated by geologists to be on an average not less than six, eight, and perhaps even a greater number of miles in depth.

Were they removed therefore and thrown into the
ocean, the granitic basis on which they now rest,
would be on an average at almost an equal depth
beneath the surface of the sea. It is implied accord-
ingly that the imagined continents from which the
materials of those strata are supposed to have been
drawn, were elevated a corresponding height above
the ocean.
This is distinctly indicated by Maccul-

loch.

"The immense deposits of materials which now form the alluvial tracts of the globe, the enormous masses of secondary strata which have been produced by ancient materials of the same nature, all prove the magnitude of the destruction which mountains have formerly experienced, which they are now daily undergoing. Let imagination replace the plains of Hindostan on the Himalaya, or rebuild the mountains which furnished the secondary strata of England, and it needs not be asked what is the extent of ruin, modern or ancient. In this ruin the highest rocks participate most largely; so largely that we can scarcely hope to find one portion of that surface which was once most elevated above the waters. If in the progress of such extensive destruction, thus probably acting on the primary rocks at two distinct periods, every vestige of overflowing granite has disappeared, it is assuredly an event not calculated to excite surprise."-Geology, vol. i. p. 154.

He here speaks as though those deposits were

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drawn from the present mountains of the globe; that, however, is inconsistent with the views we have quoted from him on another page, and is erroneous; as is shown by the proofs we have adduced, that the elevation of our present mountains took place mainly since the formation of the principal strata. His exemplification, nevertheless, serves to indicate the extraordinary height which the theory ascribes to those imagined continents. The super-position upon England of a mass of granite mountains in height as many miles within a fraction above the present surface, as the under surface of the lowest of its stratified rocks is below that line, which is reckoned at an average of seven, eight, seven, eight, or even ten miles, would give the elevation which the corresponding portion of the supposed granite continent or island must have possessed in order to have furnished the materials of those strata. The only deduction required is that of the average of the present surface above the level of the ocean, which is but a few hundred feet. The height of the imagined continent or island must accordingly have been far greater than of the loftiest present mountains of the earth, or at least six, seven, or eight miles.

On the other hand, on the supposition on which he here seems to proceed, that the materials of the strata were derived from the present mountains, the bases of which they surround, then the super-position on

the Himalaya and the table lands on which they rest, of an equal area of the strata of the plains of Hindostan, would give the height which those mountains must, according to the theory, originally have possessed; which, if those strata are on an average like those of England, six, seven, or eight miles in depth, would raise that mountain range to the height of eleven, twelve, or thirteen miles.

Making the most moderate estimate, therefore, of those supposed continents and islands, they must have soared to a height immensely above the loftiest summits of those that are now on the earth. Their existence is, accordingly wholly incredible, and would have altogether precluded the effect which they are employed to explain. For their whole surface must have towered to such a distance within the regions of perpetual congelation as to have been buried to a vast depth in snow, on the supposition that sufficient vapor to form snow ascended to such a height in the atmosphere, and rendered it impossible that any considerable streams should have flowed from them to bear their loosened particles and broken fragments into the surrounding sea; and if no vapor ascended to that height, then no water or snow could have fallen on them, and thence no rivers could have run from them and borne their detritus to the ocean. No condition can be imagined presenting a more absolute barrier to their disintegration

and transference to a distant scene. No animals or vegetables could have lived on such frozen lands; and probably no such warmth could have been communicated by the sun to the sea as to have fitted it for the existence af animals like those that are buried in the strata. What an extraordinary conception of the methods taken by the Almighty Creator to prepare the world for the residence of man! Where in the annals of crude and thoughtless speculation can a more absurd and monstrous extravagance be found?

Not to insist, however, on this embarrassing condition of their theory; let us suppose that those fabulous continents and islands were not of such an incredible and fatal elevation, but only of the height of our present continents, and were diversified like them in their surfaces; and they must still have been wholly unsuited to the purpose for which geologists invent them; for, consisting exclusively of granite, there could not have been any permanent rivers on them like those of the present earth, by which their detritus could have been borne down to the ocean. No matter how much rain fell, no springs like those that form our rivers could have risen from their surface; inasmuch as a soil that is permeable by water, strata, and strata that are at an angle with the horizon, are indispensable conditions to the existence of such springs. The supposition of water rising through unstratified rocks by the force of gravity is a solecism. It is only

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