DescrOtion of the Surface of the Earth When we take a very general view of the earth, it appears as a globular solid mass, whose surface is di versified by numerous eminences, of various magnitudes and forms.
2. Experience teaches us, that the great fossil masses, of which the solid body of the earth is composed, when viewed on the great scale, have a tabular form, and arc consequently more extended in length and breadth than in thickness.
We also find that these masses or rocks arc com posed of different minerals, in various states of aggre gation. Of these the earthy form the greater portion of the earth, while the saline, inflammable, and metal lic minerals occur in very various and remarkable re lations, in the greater and more prevalent masses, yet always in such a proportion, that when viewed on the great scale, they do not contribute to the formation of the figure of the earth or its surface.
3. When we examine the surface of the globe more particularly, a certain locality of its inequalities is to be observed. Thus the most considerable inequalities, those, namely, which present the most frequent and the deepest sections and fissures, are always found in the more elevated regions; while in the lower places we observe very few, and by no means such special elevations and depressions. We further observe, that the masses of which the higher and lower parts of the earth are composed, are by no means of the same na ture. The elevated, rugged, and very uneven places, are mostly composed of rocky masses, which present to the eye rough, bare, and fissured cliffs, mural preci pices, and even entire rocky valleys. On the other hand, in the lower parts of the earth, we find in gene ral earthy masses, as clay, loam, sand, and rolled stones ; but neither cliffs nor rocky valleys, and only single blocks of the materials of the more elevated places.
4. There is still another general and very interesting observation to be made, namely, that the remains of organic beings more or less changed, (what are deno minated petrifactions,) are found embedded in these rocks. These remarkable bodies are generally found in the middle and lower heights of the earth. In the middle heights they are still very rare ; but they in crease in variety and number, as we approach the lower places, and are at length accumulated in immense quantities in the lowest parts. We also observe, that
the organic remains found in the middle heights are totally changed into stone ; but the lower the situa tion, the more these bodies appear unaltered, or ap proach to their original state. It is also observed, that the higher places afford different genera and spe cies of petrifactions from those found in the lower ; and although we are able to show the originals of some of those petrifactions which are found in lower places, as proofs of their origin, those found in the middle heights belong to species that are unknown to us. Lastly, we may remark, that in all the situations al ready mentiohed, that is, from the middle to the low est heights, but particularly in the latter, there are some rocks in which few or no traces of such organic remains have ever been found ; although, from the local situa tion of the rocks, we might as readily expect to find pc trifactions in them, as in other rocks of the same rela tive height.
5. When we examine the surface of the earth more particularly, we find that the special inequalities are in cluded in others more general ; that these general ine qualities are again contained in others still more gene ral ; and that at length the whole are included in the most general. These inequalities may be divided into five classes or degrees. The first contains the most general inequalities ; these are the bottom of the sea, and the dry land. The second comprehends what may be termed low country and high country. The third, which is more special, comprehends mountain groups-. The fourth, which is still more particular, comprehends mountain chains and -valleys. The fifth and last, which is the most special, comprehends single mountains, and the ravines or valleys between them. We have thus a most beautiful series, from the single mountain and the ravine to the great fabric of the high country ; and still further to the most general division of the inequalities of the earth's surface, the dry land, and the bottom of the sea.