Box 3, Folder 5: Typewritten Letters, 1848

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producing very marked changes in the appearance of things. Water penetrates the rock, filling its minutest cavities, and being then congealed, expands with an irresistible force and bursts as under the most solid material. This expansion must necessarily break off fragments of rock, exposed to the weather which falling down, soon makes a pile of debris as it is called at the foot of the cliff. The more open and porous the rock, the more rapid will be the disintegration. The process will be continued until the face of the cliff is completely covered with accumulate debris, and thus protected from the frost.

Volcanoes produce great and very important changes in the earth. At one eruption of a volcanic mountain in Iceland in 1783, the quantity of lava was such as to fill the valley of a river to the depth of 600 feet, causing its waters to accumulate and overflow the land to that depth. Every eruption produces of course some change.

But the greatest and most prolific source of change is the earthquake. We read of violent earthquakes causing great destruction to cities and villages; and they are justly regarded with dread in those countries where they are of frequent occurrence. The one time that occurred on the Mississippi river in 1811, described by Flint, although it caused but little destruction of life and property, for the country was then but little settled, may serve to give us some idea of such phenomena.

"Lakes of twenty miles in extent were made in an hour. The whole country from the mouth of the Ohio to the mouth of the St. Francis, a distance of 300 miles, was convulsed to such a de

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-gree as to create lakes and islands, the number of which is not yet known; to cover a tract of many miles in extent with water three or four feet deep; and when the water disappeared a stratum of sand of the same thickness was left in its place. The trees split in the midst, lashed one with another, are still visible over great tracts of country inclined in every direction and at every angle to the earth and to the horizon. The undulations of the earth are described as resembling waves, increasing in elevation as they advanced and when they had attained a certain fearful height the earth would burst and vast volumes of water and sand were discharged as high as the tops of the trees:

Mr. Flint saw great numbers of these "chasms which remained fearfully deep, although in a very tender alluvial soil and after a lapse of seven years. Whole districts were covered with white sand so as to become uninhabitable. The bursting of the earth just below New Madrid, arrested the Mississippi in its course and caused a reflux of its waters, by which, in a little time, a great number of boats were swept by the ascending current into the mouth of bayou, carried out, and left upon the dry earth, when the accumulating waters of the river again cleared their current."

It would be strange indeed, if such violent proceedings leave no marked and permanent changes, as memorials of their existence.

One of the most remarkable earthquakes of recent times, is that which occurred in Chili on the 19th of November, 1822, first described by Mrs. Graham, an English lady; and her account, though its accuracy was at first questioned, has since been fully confirmed.

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"At [half] past 10 o' clock in the evening", says Mr. Robinson, an eye witness at Valparaiso, "appalling shocks of an earthquake began; everything on the surface was in motion; the hills near at hand oscillated; the ground rose and fell; houses reeled like ships on the ocean; Trees waved, as if bent by a blast of wind waters, before still, began a rustling movement of the earth opened; the distant mountains rocked; the sea retired; and the tremendous convulsion seemed to threatened universal dissolution. The animals, wild with terror, ran away or sought protection of man, who himself fled, he knew not whither. In a moment more, the crash of falling roofs and walls, the cries of those imprisoned in their falling houses and the shrieks of those buried beneath the [ruins], invoking their saints, or imploring the mercy of God, filled the air. Neither man nor animals could move without staggering." (Silliman's Jour. vol. 30. p. iii).

"The sea at first rose to a great height and then receded so as to leave the small vessels that were before afloat, dry on the beach; it then returned again, but not to its former level. All this happened in one quarter of an hour.. On the morning of the 20th (continues Mrs. Graham), I perceived from a small hill, that an old wreck of a ship, which before could not be approached, was now accessible from the land, although its place on the shore had not been shifted; and some rocks were exposed, on which the fisherman collected the scallop, shellfish, which rocks were not known to exist before the earthquake. I found the bed of the sea laid bare and dry, with beds of oysters, muscles, and other shells adhering to the rocks on which they grow."

It was subsequently found that the whole coast of Chili was raised on an average about six feet above its former level.

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Here is a permanent change of the level of the land produced by an earthquake under our own direct observation; and there is no good reason why this process may not in time elevate the coast to the height of the highest mountains. A repetition of the phenomena is all that is necessary; and if we allow sufficient time we shall have no difficulty in coming to the conclusion that our present mountains, continents, and islands have been elevated.

But earthquakes do not always work with such violence. We have some remarkable instances when they are carrying on their elevating process quietly and in a much more business-like way. Some portions of the coast of Sweden have been rising out of the sea at the rate of four or five feet in a century. Recently the elevation appears to have taken a new start in some places, so that harbors, that had sufficient water only a few years ago, are now inaccessible. The elevation appears to be not a gradual and constant upward action, but sudden movements and at uncertain periods.

On the other hand the coast of Greenland is found to be gradually sinking beneath the waters of the ocean. The remains of ancient buildings that were founded upon dry land are now seen covered by the tides. Villages are deserted, in consequence of the influx of the waters. At one place the stakes or piles driven at the shore, for the purpose of fastening boats, are now to be seen at some distance out in the water and others have to be prepared as the sea gradually encroaches upon the land.

There are many facts going to prove that the North American coast is, or recently has been subject to a remarkable change

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of level. While the coast of the Southern states appears to be but recently redeemed from the ocean, the coast of Labrador indicates an opposite change. At a recent session of the Association of American Geologists, the turning point or pivot on which the coast is turning, was decided to be Plymouth Rock:

An examination of the country about the head of our Lake Michigan will yield evidence of the elevation of the land. The numerous parallel sandy lake beaches which are there found extending a great distance into the interior can be accounted for in no other way satisfactorily, as upon the supposition that the land there is gradually rising. What but an elevation of the land could stop the flood of the waters of Lake Michigan towards the Mississippi river, where they once evidently ran? This interesting subject deserves more attention than it has yet received and will undoubtedly result in bringing to light some interesting facts in the history of the world.

But I have said enough to convince anyone that, so far is the earth from being finished, that it is constantly undergoing great and important changes. Change appears to be a universal law impressed upon all matter by the Creator. There is nothing permanent, nothing exempted from this great law of nature. All is motion, progress.

The present continents were once the bed of the ocean and it is probable that ancient worlds are now buried beneath its depths.

To bring this more clearly to your minds I have here for exhibition some sea shells blasted out of the solid limestone rock, at Mr. Durand's lime quarries in this city; and, in order to