which give to the line of their coasts a great length. Others present a mass more compact, more undivided; their trunk is, as it were, deprived of members, and the line of the coasts, simple and without numerous inflections, is comparatively much shorter.

Considered under this aspect, the three principal continents of the Old World form a remarkable contrast.

Africa is far the most simple in its forms. Its mass, nearly round or ellipsoidal, is concentrated upon itself. It thrusts into the ocean no important peninsula, nor anywhere lets into its bosom the waters of the sea. It seems to close itself against every influence from without. Thus the extension of the line of its coasts is only 14,000 geographical miles, of 60 to the degree, for a surface of 8,720,000 square miles; so that Africa has only one mile of coast for 623 miles of surface.

Asia, although bathed on three sides only by the ocean, is rich, especially on its eastern and southern coasts, in large peninsulas, as Arabia and the two Indies, Corea, Kamtschatka. Whole countries push out into the ocean, as Mandchouria and China. Nevertheless, the extent of this continent is such, that, in spite of the depth of the indentations, there yet remains at its centre a greatly preponderating mass of undivided land, which commands the maritime regions as the body commands the limbs. Asia is indebted to this configuration for a line of coast of 30,800 miles; it is double that of Africa, which is, nevertheless, only one third smaller. Asia, therefore, possesses a mile of coast to 459 square miles of surface.

Of all the continents, Europe is the one whose forms

of contour are most varied. Its principa! mass is deeply cut in all parts by the ocean and by inland seas, and seems almost on the point of resolving itself into peninsulas. These peninsulas themselves, as Greece, Scandinavia, repeat to infinity the phenomena of articulation and indentation of coasts, which are characteristic of the entire continent. The inland seas and the portions of the ocean its outer limits enclose, form nearly half of its surface. The line of its shores is thus carried to the extent of 17,200 miles, an enormous proportion compared with its small size; for it is 3,200 miles more than Africa, which is nevertheless three times greater. Europe enjoys one mile of coast for every 156 square miles of surface. Thus it is the continent most open to the sea, for foreign connections, at the same time that it is the most individualized, and the richest in local and independent districts.

In this regard there is, as we see, a sensible gradation between the three principal continents of the Old World. Africa is the most simple; it is a body without members, a tree without branches. Asia is a mighty trunk, the numerous members of which, however, make only a fifth of its mass. In Europe, the members overrule the principal body, the branches cover the trunk; the peninsulas form almost a third of its entire surface. Africa is closed to the ocean; Asia opens only its margins; Europe surrenders to it entirely, and is the most accessible of all the continents.

America repeats the same contrasts, although in a less decided manner. North America, like Europe, is more indented than South America, the configuration of

which, in the exterior at least, reminds us of the forms of Africa, and the uniformity of its contours. The two continents of the New World are more alike. Nevertheless, the line of the shores is much more extended in North than in South America. It is 24,000 miles in the former, or one mile of coast to 228 square miles of surface; in the latter, it is 13,600 miles, or a mile of coast for 376 miles of surface.

The following table represents these differences of configuration of the continents by numerical proportions. The mile here employed is the geographical mile, of 60 to the degree. It is the only one we shall make use of in the course of these lectures.

It is to Ritter, moreover, as well as to Humboldt, that science is indebted for the appreciation of the value of the relations of size, of relative position of each of the continents, the influence of which, in nature and in history, will appear constantly greater the further we advance in our inquiries.

The exposition we have just made has shown us at once differences and analogies in the forms and dis

position of the continental or land masses.

The differences prove that each continent, or each group of continents, has a character peculiar to itself, and in some sort individual. The analogies lead us to suspect the existence of a general law; they disclose an arrangement which cannot be without a purpose; now, this purpose it will be our duty to seek to comprehend, in we would attain to the true understanding of this part of Creation.

LECTURE II.

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Recapitulation - Vertical dimensions or forms of relief — Difficultie presented by their study — Usefulness of profiles — Great influence of differences of height - Elevations in mass, and linear elevations Importance of the former — Labors of Humboldt and Ritter on this subject Examination of the general features of relief of the continents- A great common law embracing them all.

LADIES AND GENTLEMEN:

The conclusion of the preceding lecture was devoted to a simple examination of the most prominent forms which the continents present to us, and such as the line of contact of the lands with the horizontal surface of the oceans exhibits to the eye. In this first review, we have followed, step by step, in their discoveries, the men of science who were the first to point them out. We have recognized, with Lord Bacon and Forster, the tapering form of the southern points of the continents, their gulfs on the west, and their islands on the east; with Pallas, the situation of the great plains in the north of the Old World, and the east of the New; with Humboldt, the winding forms and parallel shores of the great oceanic valley bearing the name of the Atlantic; with Steffens, the enlargement of all the lands towards the north, and the characteristic grouping of the continents in three double worlds. Ritter, finally, has

shown us how almost all the lands are combined in one hemisphere, which may be contrasted as a continental