We will next consider the Ocean in a physical and geographical point of view.

The sea, as a whole, occupies more than two thirds of the surface of our globe. The distribution of the waters is another still more important point to consider. We know that, far from being equally distributed over the earth's surface, there is, on the contrary, the greatest diversity in this respect. It seems as if the land had been concentrated around the North Pole, whilst the opposite part of the spheroid is almost exclusively covered with water, so that if the northern hemisphere be designated as the continental hemisphere, the southern hemisphere deserves with still more reason the name of the aquatic hemisphere.

The relation of the sea to the land, and the manner in which this great body of salt water is separated by the continents, has caused it to be divided into several basins which we designate under the name of oceans. Thus we distinguish the Atlantic Ocean, the Pacific Ocean, the Indian Ocean. In certain respects these basins may be considered as mere gulfs of the great reservoir around the South Pole.

Each of these oceans has a character of its own, independent of those peculiarities which arise merely from the climate or the animals that live in it. Thus the leading feature of the Pacific Ocean consists evidently in the endless number of islands and archipelagoes which are scattered all over its surface. The Atlantic Ocean, on the contrary, has very few islands; but its shores are more varied. There is no other ocean which combines itself in so many ways with the land; where we find, for example, so many promontories projecting into the sea, and so many gulfs and sounds penetrating into the land. The consequence of this is a great amount of coast in a small space, as we see it exemplified in the coast of the United States, and in a still higher degree in the coast of Europe, where it has had a paramount influence upon civilization. The Atlantic is besides remarkable for having the greatest number of inland seas, which, although connected with the Ocean, are nevertheless so completely surrounded by the land as to be in some degree independent of its influence, and thus to have a character of their own; as, for example, the Baltic, and, above all, the Mediterranean. We may likewise cite as belonging here Hudson's Bay, and in some degree the Gulf of Mexico, all of which are connected with the Atlantic. The Indian Ocean, although less strongly

characterized than the two preceding, nevertheless, from the peculiarity of its long peninsulas derives a character of its own, which is not without importance, especially when consid ered with reference to navigation.

A thorough investigation of the Ocean ought not to be limited merely to its form and extent. The depth of the sea must likewise be taken into consideration. As a general rule, it may be stated that the sea is less deep near the coast than at a distance from it. Thus the coast of the United States is bordered in its whole length by a zone of shallow ground, which, according to its peculiar shape, has been designated under the names of shoals, flats, and banks, the knowledge of which is of the highest importance for navigation. A similar zone is to be traced along the coast of Europe and especially around the British islands. The average depth of the North Sea is less than two hundred feet, so that an upheaval of some hundred feet would suffice not only to connect the British islands with the continent of Europe, but also to double its area. There are geological reasons to suppose that at a previous geological epoch, a direct connection existed between England and France, and also between England and Ireland. Some eminent naturalists have even tried to explain in this way the fact that the animals and plants of the British islands are the same as those of the continent, supposing that they have migrated into the British islands at the time when this connection existed.

We do not yet possess a sufficient amount of soundings to enable us to draw a comparison between the depths of the different oceans, although there is every reason to suppose that they are also in this particular different from each other. Laplace had tried to demonstrate by astronomical considerations, that the depth of the Ocean ought to be proportionate to the elevation of the continents. But recent investigations of the average elevation of the continents do not seem to support this view. Indeed, according to the calculation of Humboldt, (which of course can be but approximate,) the heights of the continents, supposing the inequalities of their surface reduced to the same level, would be, for Europe, 600 feet; for America, 1,050 feet; and for Asia, nearly 1,100 feet. Now the soundings we possess, although not very numerous, nevertheless authorize the assumption that the average depth of the Ocean far exceeds this amount. There is no ocean in which there has not been found a depth of

several thousand feet. Thus we know that in the Arctic Ocean, whose bottom is very uneven, in latitude 76° N., Scoresby did not find ground at 7,200 feet. Captain Ross found as much as 6,000 feet in Baffin's Bay. The Atlantic, opposite the coast of the United States, has been sounded in several places by the officers of the United States Coast Survey, who have found from 6,000 to 8,000 feet. But the great basins of the southern seas are above all remarkable for their great depth. We know that Captain Ross, at the west of the Cape of Good Hope, sounded 15,000 feet, and the same navigator did not reach the bottom with a line of 27,600 feet, west of St. Helena; a depth which is almost equal to the height of the loftiest peak of the Himalaya chain. By combining these facts with other considerations connected with the form of the surrounding continents, some recent geographers have come to the conclusion that the average depth of the Atlantic must be at least two miles and a half, and that of the Pacific at least three miles.

As to the inequalities of the bottom of the Ocean, it is stated by some navigators that they are even much more considerable than those of the land. According to Captain Wilkes, the great depressions, or submarine valleys, run nearly at right angles to the great mountain chains of this continent; there is, at the equator, a depression to nearly the 5th parallel of south latitude, where a ridge occurs; at the 15th parallel, there is another depression to be found; 10 degrees further south we have another ridge; and it again increases and then lessens in depth twice towards the polar circle.

It remains to consider the Ocean as one of the productive agents in the economy of Nature. Howsoever important the Ocean may appear when examined from the points of view already considered, they do not constitute its only or even its chief claim to our attention. To consider the phenomena of Nature merely in their connections with one another, to look only at their useful or agreeable side, is to judge the works of God from a narrow point of view, and to mistake their true signification. Every object in Nature exists in itself and for itself, before it forms a part of any whole; in other words, it bears in itself the reason of its existence. It is true, the oak in the forest combines with other trees to furnish food for the beasts of the field and a shelter for the birds of the air; it is true, a shady bower gladdens and refreshes us with its

greenness and its shade; but shall we judge from this that these things have no other part to play in Nature? Shall we rest contented here that we have learned all the meaning of the Pole-star, because it renders such signal services to the sailor struggling against the storm, or because it serves as a faithful guide to the slave in his nocturnal pilgrimage journeying towards the land of freedom? No more does the Ocean exist solely to serve a useful purpose, and for the sake of its connection with the rest of the universe. Before the first canoe ventured on its waves, it washed the continents as now; and before animals dwelt in its bosom, it covered with its waters the face of this youthful sphere. Then as now it had a signification independent of its form and of its relation with the rest of the material world: it was the Ocean majestic and powerful as at this day. To comprehend it in all its grandeur, in all the extent of its influence, it is not enough to study it in its present form and its actual condition; we must study the Ocean in its history and in its development.

The doctrine that the Ocean is the germ or point of depar ture of all things, a doctrine announced in the old cosmogonies and laid down as a principle in the philosophical schools of the Greeks, is now demonstrated by the results of geological research. In short, geology teaches us not only that the relations of the continents with the Ocean have been different at different geological epochs, but in going back through the geological ages we come to an epoch when, according to all appearances, the solid earth did not exist, and when the surface of our globe was entirely covered with water. This was the period of "chaos"-a term which does not by any means imply confusion, but merely the absence of separation, a general homogeneousness containing the principles of all the elements which were thenceforth to be developed; and in this sense an egg is a chaos- though it contains the elements of the young chicken hereafter to be developed.

The materials which form the greater part of the solid land were prepared in the bosom of the waters. As we trace on a geological chart the successive formations which we know are of aquatic origin, we commonly arrive at a point where what are now entire countries are represented by only a few islands. Little by little these islands become enlarged, the spaces which separate them become filled up, and vast tracts of firm land appear to-day where once the Ocean reigned as absolute master. This is not the place to inquire what part has been

performed by the different physical agents in the history of the formation of the continents: to do this it would be necessary to enter the department of Geology, and to discuss anew the old questions so often agitated by the geologists, and which at the beginning of this century gave rise to the celebrated controversy between the Vulcanists and the Neptunists.

Leaving out of sight for a moment the agents which have built up the continents, we assume as a fact, that from the time when the solid earth first existed, it must enter into opposition with the liquid element and occasion a series of actions and reactions, which not only constitute the peculiar characteristic of various portions of the earth, but are the conditions of all terrestrial life. It is enough for us to remind the reader that by means of evaporation, which continually takes place at the surface, the Ocean constantly imparts a portion of its waters to the atmosphere, which is again precipitated on the firm land in the form of rain and dew, thus facilitating the development of animal and vegetable life, which could not subsist without this supply. Consequently, to remove the Ocean from the face of the globe would be not only to put to death all the inhabitants of the sea; it would be to extinguish all life on the surface of the firm land, and consequently to destroy its signification.

It is thus that the continents, which, geologically speaking, are the descendants of the Ocean, after their birth are dependent thereon, and are never entirely emancipated from its control. Even the desert, which never receives a drop of rain, is not independent of the Ocean; arid as its soil may be and burning as is its air, nevertheless it receives a certain quantity of moisture from the sea, and without this it would be completely impenetrable.

But this is not the only action of the Ocean upon the land: it acts directly thereon by modifying the form of its shores. We need only cast our eyes on any portion of the sea-coast, to discover more or less striking marks of oceanic action. Sometimes promontories are washed away by the violence of the waves, bays are filled up; here islands disappear, there new islands rise up. In one word, there is a continual change going forward in the form of the shore or in the depth of the water.

In general, the attention of man is chiefly directed to the destructive power of the Ocean. The invasions of the Ocean, the ravages of every sort which it commits, are mentioned in