encroaching influence of the waves, we would not be credited by many-the assertion would seem that of one whose avocation was the excitement of astonishment, and who if he could make his reader wonder, had attained the acme of his ambition. Yet such, nevertheless, is the conclusion, to which all who study the structure of the earth, divested of prejudice and preconception, are necessarily led."

If we look with wonder upon the great remains of human works, says Sir H. Davy, such as the columns of Palmyra, broken in the midst of the desert; the temples of Pæstum, beautiful in the decay of twenty centuries; or the mutilated fragments of Greek sculpture in the Acropolis of Athens, or in our own museums, as proofs of the genius of artists, and power and riches of nations now passed away; with how much deeper feeling of admiration must we consider those grand monuments of nature which mark the revolutions of the Globe; continents broken into islands; one land produced, another destroyed; the bottom of the ocean become a fertile soil; whole races of animals extinct, and the bones and exuviæ of one class covered with the remains of another; and upon the graves of past generations—the marble or rocky tombs, as it were, of a former animated world-new generations rising, and order and harmony established, and a system of life and beauty produced out of chaos and death; proving the infinite power, wisdom, and goodness of the GREAT CAUSE of all things!

From the numerous foreign writers, who at a very early period began to entertain correct notions of the structure of our planet, and of the nature of the revolutions which it had undergone, we are induced to select the following highly philosophical and beautiful illustration of the physical mutations to which the surface of the earth is perpetually exposed. It is from an Arabic manuscript written in the thirteenth century. The narrative is supposed to be given by Rhidhz, an allegorical personage.

"I passed one day by a very ancient and populous city and I asked one of its inhabitants how long it had been founded? 'It is, indeed, a mighty city,' replied he; 'we know not how long it has existed, and our ancestors were on this subject as ignorant as ourselves.' Some centuries afterwards, as I passed by the same place, I could not perceive the slightest vestige of the city. I demanded of a peasant, who was gathering herbs upon its former site, how long it had been destroyed?' 'In sooth, a strange question,' replied he, 'the ground here has never been different from what you now behold it.' 'Was there not,' said I, 'of old a splendid city here?' 'Never,' answered he, 'so far as we know, and never did our fathers speak to us of any such.'

"On my return there again, after the lapse of other cen-. turies, I found the sea in the same place, and on its shores were a party of fishermen, of whom I inquired how long the land had been covered by the waters? 'Is this a question', said they, 'for a man like you? This spot has always been what it is now.'

"I again returned ages afterwards, and the sea had disappeared. I inquired of a man who stood alone upon the ground, how long the change had taken place, and he gave me the same answer that I had received before.

"Lastly, on coming back again after an equal lapse of time, I found there a flourishing city, more populous and more rich in buildings than the city I had seen the first time; and when I would have fain informed myself regarding its origin, the inhabitants answered me, 'its rise is lost in remote antiquity—we are ignorant how long it has existed, and our fathers were on this subject no wiser than ourselves.'"

We may smile at the ignorance of the inhabitants of the fabled cities, but are we in a condition to give a more satisfactory reply should it be inquired of us, 'What are the physical changes which the country you inhabit has under

gone?—and yet cautious observation, and patient and unprejudiced investigation, are alone necessary to enable us to answer the interrogation.

Dismissing from his mind all preconceived opinions, the student must be prepared to discover that the earth's surface has been, and still is, subject to perpetual mutation, -that the sea and land are continually changing place,-that what is now dry land was once the bottom of the deep, and that the bed of the present ocean will, in its turn, be elevated above the water and become dry land, that all the solid materials of the globe have been in a softened, fluid, or gaseous state, and that the remains of countless myriads of animals and plants are not only entombed in the rocks and mountains, but that every grain of sand, and every particle of dust wafted by the wind, may teem with the relics of beings that lived and died in periods long antecedent to the creation of the human race. Astounding as are these propositions, they rest upon evidence so clear and incontrovertible, that they cannot fail to be admitted by every intelligent and unprejudiced reader, who will bestow but a moderate share of attention to the phenomena, of which it is the purport of this work to offer a familiar exposition.

Scott, in his "Marmion," refers to a legend once prevalent in the neighborhood of Whitby, that the ammonite shells, which are common in that vicinity, had formerly been snakes, which the foundress of the abbey, St. Hilda, succeeded in decapitating by her prayers, and then converting into stone:

We shall now proceed to lay before the reader some of the data connected with the stratification of the earth, which

lead to the conclusion of a vast antiquity, and of the physical revolutions it has undergone since it has become a planet. Our limits forbid us from entering into detail on all the multifarious forms which geology has disclosed to our observation, nor, were we doing so, could it prove interesting to any of our readers, except such as have made comparative anatomy more or less their study, nor will our limits allow of more than a general notice of the most remarkable of those forms which peopled our planet prior to the existence of our own species.

"Every rock in the desert, every boulder on the plain, every pebble by the brook-side, every grain of sand on the sea-shore, is replete with lessons of wisdom to the mind that is fitted to receive and comprehend their sublime import."

The rocks of which the crust of the earth is chiefly composed, occur in beds or layers; on examining them we find every evidence of their having resulted from matter carried by rivers into lakes, estuaries, or seas. This is demonstrable from some of them being composed of fragments of other rocks worn and rounded by the action of water, so as not to be distinguished from the gravel strewed upon the shore, or which we meet with in the path of a mountain stream, except in its having been consolidated into a stony masssuch rocks are called conglomerates. The red sandstone

formations of Arran, and the coasts of Argyle and Ayrshire, Scotland, consist of immense beds of such rocks, alternating with layers of red clay, and red sandstone. This formation itself is many thousand feet thick; we never find in it any fragments of the coal, or of any newer formation; on the contrary, the conglomerates consist solely of pieces of quartz, slate, red sandstone, and other rocks of more ancient date. In the same formation, which stretches from Argyle through Stirlingshire and Forfarshire, to the eastern coast, remains of fishes in a very perfect state of preservation, have been found. In both the conglomerates then, and in the

fishes we have evidence of this formation having been produced, not instantaneously, but through a long succession of ages. Each bed of pebbles, if the ancient agencies of nature were any way analogous to the present, must have been the work of many years. That these agencies were not more violent, or at least that there were long intervals of repose, is attested by the beds of fine grained sandstone, and consolidated mud, with which the conglomerates alternate. The largest of our existing rivers, in rainy seasons, carry great quantities of gravel, sand and mud, into their estuaries or the sea; but great as the amount of debris is, the production of a quantity of matter, any way equivalent to the old red sandstones of England and Scotland, could not take place except in the lapse of innumerable ages. The mud carried down by the Nile, and deposited, amounts only to a quarter of an inch thick annually. The old red sandstone formation is estimated at from three to four thousand yards in thickness. Allowing a quarter of an inch as the average annual aggregation of matter, this formation alone could not have been deposited in less than 432,000 years.

If we contemplate for a moment the agencies that must have been engaged in wearing down the surfaces of the ancient rocks, and in transporting them over the vast areas they now occupy, the time here stated will not seem any way exaggerated, but far too little for the amount of the effects produced. We have mentioned the old red sandstone formation as an instance, from which something like an idea may be formed of the time requisite for the production of a certain class of rocks. The same, or even still more decisive proofs of the lapse and change of time are afforded by the other formations.

To disintegrate to any considerable extent a solid rockto transfer the material by a river-current to any oceanic site to deposit it, and consolidate the deposition, are exces