relics of former times preserved in the mineral masses of which its exterior is composed. An inquiry which starts where human records begin to be obscure, and carries back the imagination through successive eras, to a point in the infinity of the past which the mind can scarcely contemplate-a period coeval with the origin of the earth. It exhibits the surface of the earth as having been subject to a series of extraordinary and violent changes-of sudden and mighty revolutions. It details "the war of elements and wreck of matter," the successive destruction and reproduction of this fair scene of man's abode, and innumerable races of animals, ere he, the self-styled "lord of creation" had assumed dominion upon the earth. As in the history of nations, we observe a gradual developement of the human faculties-a progressive emergence from barbarism, in which most civilized nations have had their origin, to that intelligence which afterwards distinguished them, so in Geology, we discover a remarkable succession in organized beingsan apparent gradation from animals of a simple to those of a complex structure, and by ascending the series we arrive at a period anterior to the existence of life upon the earth when it "was without form and void, and darkness rested upon the face of the deep." The earth itself, like society or an individual, appears to have passed from infancy to adolescence, from adolescence to maturity, from maturity to old age, which her present feeble energies, compared with her pristine vigour, seem to indicate.

The key to this long-concealed volume of nature, and to all its mystic revelations, is the extraneous fossil, (as it is termed,) the organic remains embedded in the

solid framework of the globe. By means of these, we are enabled to arrange the apparently innumerable strata into certain orders and classes, and assign to each a definite epoch, or period of formation; and hence establish the extraordinary fact that there is throughout these mineral masses an invariable order of superposition, which in the numberless derangements and convulsions which have shaken the earth to its centre, has never been inverted : that this order of superposition is not confined to this or that locality, but is essentially the same in the old world and the new, from the arctic to the antarctic circle; as far at least as observations have at present extended.

The discoveries of Geology, like those of Astronomy, are completely at variance with our preconceived ideas, and in some cases opposed to the evidence of the senses. Until it was proved by demonstration, it was inconcievable, that the sun which rose and set and appeared constantly in motion, actually stood still: so the mind is indisposed to believe that the solid earth on which we tread, on which innumerable generations of men have lived and died, and our cities have stood from the earliest times, has been by turns, perhaps, the bed of a sea, the bottom of a lake, or matter ejected from beneath by volcanic agency. At one period buried beneath the dark abyss of the ocean, at another smiling with verdure on its shores-the abode now of sterility-now of fertilitynow of marine and now of terrestrial animals and plants. Yet even so is it with almost every portion of what we now call terra firma, which is, in fact, one vast sepulchre of animated beings! The highest mountains have not escaped the general fate-the "everlasting hills" can no longer with propriety be cited as the emblem of immutability.

What, short of actual demonstration, would convince us that the tops of the highest mountains in England once formed the bed of the sea? and that strata now buried hundreds of yards beneath the surface were once elevated above its waters? But we have unquestionable evidence of this mighty boulevèrsement records as clear as any that Herculaneum and Pompeii can exhibit of their former condition. The insignificant little specimen, of which the engraving (1) in the margin is a representation, is a fossil shell, (once an inhabitant of the ocean) from the top of Snowdon,

1

2

the highest mountain in Wales, broken with my own hands from myriads of others in the mass of limestone * which caps its summit. The other engraving (2) represents a specimen of the vegetable productions which adorned the hills of the primeval world (perhaps subsequently to the upheaving of the ocean deposit of which the specimen just described is a relic) disentombed from the bowels of the earth at a depth of one thousand feet beneath its surface in this County!†

Now the evidence in this case is

* The occurrence of this limestone on the apex, the extreme point of this mountain, while its mass is composed of older rocks destitute of organic remains, is a remarkable feature in the Geology of Wales.

+ Leicestershire. From the Ashby-de-la-Zouch coal-field.

irresistible, it amounts to demonstration, that the ocean covered the spot where the shell was found, and remained there during a long period of time, for the limestone is formed almost entirely of shelly fragments; and that vegetation with all its conditions, light and heat, soil and atmosphere, once existed where the fragile plant was preserved. It could not have been transported thither, for its delicate texture would have been injured in the removal, whereas its fibres are as nicely preserved as if the plant had been carefully enclosed between the leaves of a book.

Not only are some of the facts opposed to all experience and previously-acquired ideas, as we have seen, but Geology also involves an apparent contradiction of terms-for the lowest in the series sometimes occupy the highest level, and vice versa. Thus on the continent of Europe, the lowest bed, the primitive granite, on which all the other rocky masses repose, rarely makes its appearance except on the summits of the highest mountains, such as Mont Blanc and the Jung Frau, and the loftier Alps, which

"Pinnacle in clouds"

"Their snowy scalps"

presenting in these cases, not horizontal beds, as their position at the base of the whole superstructure of stratified rocks might lead us to infer, but sometimes cones of vertical strata of inconceivable height, which tower in majestic grandeur far above the reach of human footsteps,

"As if to shew"

"How earth may rise to heaven, yet leave vain man below."

Such are some of the anomalies to be encountered in the study of Geology.

It is the uniformity of superposition, the invariable order of succession, sometimes disturbed but never inverted, on which Geology depends as a practical science: the identity of a rock being proved by the fossils it contains, its position in the series is at once ascertained, and by a never-failing analogy, the position of other rocks is accurately inferred. It is a knowledge of these facts which guides the skilful miner in his expensive operations, and it is in defiance or ignorance of them, that the many abortive searches for coal have been conceived and prosecuted at so great a sacrifice of the national wealth. The often-cited case of Bexhill, near London, in which eighty thousands pounds are said to have been expended in a fruitless search for coal, which the merest tyro in Geology would in the present day have condemned, is of itself sufficient to prove the immense advantage of Geology as a practical science.

It is unnecessary to dilate upon the inestimable advantages, we derive from the skill of the miner. It would be no difficult task to prove that our mineral resources are the main-spring of our national prosperity, and one of the chief causes of that proud pre-eminence which this country occupies in the scale of nations ;-supplying us on the one hand with coal, the vital principle of manufactures, on the other with iron, the raw material of the most considerable portion of our national industry-the basis of so much ingenuity, the source of incalculable wealth and how great is the aid which the science of Geology has afforded to the miner:-how it has systematized his operations-how it has extended and is daily enlarging his dominion, they only who are practically

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