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imals) partaking of the nature of both fishes and reptiles, which receive their greatest development in the lias. The foot prints of birds are found for the first time in the Triassic or upper new red sandstone.

In the lower Oolite two mammiferous quadrupeds, of the marsupial or opossum tribe are found, as the first and only representatives of this class now so extensive. Above the cretaceous or chalk in the Paris Basin, Anaplotheroid and other races make their appearance, become extinct and give place to the Mastodon, the Ele. · phant, the Megalonix and others, which are found in the alluvial deposits on the surface. Among all these remains no traces of man or his works have been found, in a fossilized state, in any formation which is not evidently cotemporaneous.

From this it will be perceived that in the types of animal life, the creation has been successive from the less to the more perfect forms of organization. The same may said of the vegetable world. The cellular or agamic were succeeded by the endogenous; and these by the cogengenous, or phenogamous families, which at present clothe and beautify the surface of the earth. It appears, then, that the types of the organized forms found in a fossilized state, have been preserved till the present time, but the genera and species have, in most instances, been destroyed by the revolutions which have marked the past history of the earth.

We have given greater extension to this notice of the fossiliferous rocks, because two of its groups, the Carboniferous and Silurian occupy so prominent a place in the geology of the west. The Silurian system is well displayed, and attains its greatest power in the State of New York. Many of its strata thin out in proceeding towards the west, where the carboniferous (not found in the State just mentioned,) attains its greatest development. In the subjoined table, we have endeavored to present at a glance, the equivalency, or the parallelism of the formations of Europe, with those of New York and the Western States.

It yet remains to notice one more division, or class of rocks:

4. VOLCANIC Rocks, embracing basalt, trachyte, diorite, and other igneous rocks, are of limited extent, when compared with the fossiliferous strata to which we have referred. They are found principally in the vicinity of active or extinct volcanoes in many parts of the world. Though of igneous origin, they differ from Plutonic Rocks in being often formed of breccias and tufas, and in presenting a less crystaline and a more porous or vessicular structure. They occasionally penetrate and fill up fissures and chasms in the Plutonic and Metamorphic Rocks, and then constitute what are termed dykes. Sometimes they are found intervening between fossiliferous strata, but most frequently penetrating all the other formations in the earth's crust, capping or over-spreading them at the surface.

The peculiarities in the structure of some volcanic rocks, are not only sufficient to distinguish them from those belonging to the plutonic, but prove that though identical in their igneous origin, the circumstances which prevailed at the period of their formation were essentially different. The granites seem to have been formed under great pressure, excluded from the influence of the atmosphere and woled so slowly as more definitely to assume a crystalize structure. Volcanic rocks, on the contrary, appear to have been formed near the surface exposed to the action of the air, and to have cooled rapidly, and crystalized imperfectly. That they were formed under moderate pressure, is obvious from their want of compactness manifested in their vesicular and porous texture. ART. II. ON THE NATURAL ADVANTAGES FOR MANUFACTURING ON

We have thus attempted to present a condensed view of the nature of the formations which constitute these four clases of rocks. In this arrangement we have preferred a classification of them according to their origin, rather than their relative ages.

The relative ages of the plutonic, metamorphic and volcanic rocks cannot be properly determined; but the fossiliferous strata are not liable to the same objection, and we have availed ourselves in the following table of the distinctions according to the priority, established among them by European and American Geologists:

TABLE OF GEOLOGICAL EQUIVALENTS OF THE EUROPEAN, NEW YORK AND WESTERN FORMATIONS. PRINCIPAL GROUPS. EUROPEAN EQUIVALENTS.

NEW YORK SYSTEM.

EQUIVALENTS OF WESTERN STATES.

[blocks in formation]

3 Sandstone schists & bituminous lime

(stone,
2 Carboniferous or mountain limestone.
11 Waverly sandstones.

Carboniferous.

Carboniferous of England.
Yellow sandstones of Ireland.
Old red sandstone of Scotland & Wales. 28. Sandstones and schists,

Old red sandstone.

"}

[graphic]

3 Fossiliferous Rocks.

27. Chemung group.

26. Portage group. Eifel

25. Genessee slate.
24. Tully limestone.
23. Hamilton group

22. Marcellus slate.
Devonshire

21. Carniferous limestone.

20. Onondaga limestone.
Rocks.

19. Schoharie grit.
18. Cauda galli grit.
17. Oriskany sandstone.
16. Upper pentamerus limestone.

15. Delthyris shaly limestone.
Ludlow Rocks.

14. Pentamerus limestone.
13. Water lime.

12. Onondaga salt group.
Limestones and shales of Wenlock. 11. Niagara group.
Upper Carodoc of England.

10. Clinton group.
9. Medina sandstone.
8. Oneida conglomerate.

7. Gray sandstone.
Schists in Sweden over red limestone. 6. Hudson River group.

5. Utica slate.

4. Trenton limestone. Bitum’us schists & limestones of Sweden 3. Black River limestone.

2. Silicious limestone. Inferior sandstones of Sweden, &o. 1. Potsdam sandstone.

THE OHIO RIVER. “The natural elements of a manufacturing district are these : 1. Power--cheap, ample, and certain. 2. Cheap living 3. Facilities of transporting man and matter. 4. Proximity to the materials to be manufactured. 5. Nearness of the market to be supplied.

6. An healthy position and a climate so equable and temperate that man may sustain continuous labor, even in partial confinement.

7. A good site for buildings and near suitable building materials. Let us examine these in their order.

“1. POWER.—There is now scarcely any handicraft work, from the simplest to the most complicated, which is not materially aided by machinery. Hands seem to be merely required to set that machinery in motion and to direct its movements. So wonderful are the inventions of this century, that we dare not state the ratio of decrease of human labor in any branch of manufactures. A few years since we supposed that the cotton spindles and looms were perfect, or nearly 80; yet, within four or five years, a few simple improvements have been made that have reduced the number of hands in a cotton mill more than one half; and it is now said that much of the cotton machinery in England and New England is scarcely worth having.

“ The effect of these improvements is to make cheap power more important than cheap labor.

“It cannot be necessary to adduce many reasons why manufacturing should be carried on where the power is found; water power of course is stationary; and, where steam is the motive power, it is generally far cheaper to move the raw material than the coal. For example : 1,000 tons of coal are required in the manufactory for 600 tons of cotton, and from three to five tons of coal for one of iron. Certainly there are exceptions to the rule; it is cheaper to transport coal from Nova Scotia and Pennsylvania to New England, than to pay the aggregate freight on the cotton, dry goods, and provisions to and from the bleak coasts of Sidney and Pictou, or the barren hills around Frostburg and Pottsville. Perhaps this exception will be but temporary

“ All the manufacturing towns of England are in the vicinity of coal-fields. Even the woolen mills of Sussex and Essex have yielded in competition with those of the coal districts.

“ When the two are to be combined, the tendency of the bulky is to draw the heavy article to it; and the more valuable the material the better it will bear transportation.

“ The copper and tin ores of Cornwall are taken to the Welsh coal fields to be smelted; so also have been the copper ores of Cuba and Lake Superior. The

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