BOOK tic hemi sphere. Dimen sions of the AustroOriental ocean, In following this division upon the globe, many general results will evidently strike us. Is it not, in the first place, very remarkable, that one half of the globe should be covered with water, while the other half contains less water than land? In order to have Terrestrial under our view the whole of the aquatic hemisphere, we and aqua- must turn the globe so that New Zealand may form the highest point; or we must examine a map of the world, projected upon a horizon little distant from that of Paris :* the hemisphere, circumscribed by the horizon of our antipodes, presents to the view only some islands, some promontories, and some narrow lines of coasts in the midst of an immense sea; while the hemisphere bounded by our horizon comprises almost the whole of the land. If the masses of polar ice of the south do not contain some considerable islands, we can, by following the meridian of the Cape of Good Hope through the pole, till we reach the neighbourhood of Behring's straits, trace a line of two hundred degrees, or of four thousand marine leagues; a line exceeding by more than four hundred leagues half the circumference of the globe, and which passes over a surface entirely covered with water. A line drawn under the equator from Africa, through Sumatra and Borneo to America, passes over a surface of water, with only two or three interruptions, of four thousand two hundred leagues. Lastly, the fortieth parallel of south latitude affords an aquatic zone, interrupted only for fifteen degrees, and consequently forming a circumference of nearly five thousand three hundred marine leagues, a space little less than two-thirds of the periphery of the globe. Such is the vast extent of the Austro-oriental basin of the ocean upon our earth. The form of the western basin is not less striking. It resembles a channel, narrowing towards the pole, and communicating with the Austro-oriental basin, on one side by *See Le planisphère du Père Chrysologue de Gy, or the Atlas of this work. VII. the straits of Behring, and on the other by the large open- BOOK ing of the Ethiopic ocean. The Mediterranean sea corresponds to the gulf of Mexico; the Baltic and Northern seas, are opposed to Baffin's and Hudson's Bays. son of the ern hemi The distribution of water and land is also very unequal, Compariif, without considering the forms of the two grand basins northern of the ocean, we compare the hemispheres, separated by the and southequator, or the northern and southern halves of the globe. spheres. We have found, by a pretty exact computation, that the land in each hemisphere and the zone bears to the whole surface the following proportions: ern conti Geographers and naturalists, about the middle of the Is a southeighteenth century, endeavoured by various arguments to nent necesaccount for this unequal distribution of land and water. sary for the equilibriThey asserted the existence of a great southern continent, um of the which was necessary to counterbalance the mass of land globe. situated in the northern hemisphere. But the voyages of Cook have put an end to all these conjectures. That navigator found, up to the 70th degree of south latitude, only one vast sea, containing many floating masses of ice, together with a few islands which had been mistaken for the promontories of the southern continent. There remains therefore towards the pole only about five or six hundred * Bergmann's Physical Geography. I. p. 6. (2 edit. of Upsal, in Swedish,) Dalrymple's History of Navigation, Buffon, Buache, &c. &c. VII. BOOK thousand square marine leagues, in which there can be any land, inaccessible to navigators on account of the ice ;* but the whole of this mass would very little alter the proportion between the two hemispheres. Direction sulas. According to the opinion now generally admitted, that part of the land which is elevated above the surface of the sea, is so little in proportion to the immensity of the globe, that the effect of its unequal distribution upon the equilibrium of the globe is in fact nothing, or so small as to produce no sensible effect. Besides, it is possible,† that the sea towards the south pole may be less deep than in the northern hemisphere, and thus the tracts of land under the sea towards the south, may counterbalance the continental masses of the north, which are more elevated indeed, but surrounded by much deeper seas. This hypothesis would be more plausible, if the greater flattening of the globe towards the south pole, indicated by the measurements of M. La Caille, in Africa, should ever be confirmed by corresponding measurements in America, and in New Holland; for then, that hemisphere being in general more depressed than ours, the ocean by its own tendency to establish a level, would spread itself over the surface of the southern land, which would be thus covered by the sea. The two continents present a similarity of appearance in of penin- the direction of their peninsulas; they are almost all turned towards the south. This is the case with South America, California, Alascgha, Greenland, Arcadia, Florida, Scandinavia, Italy, Greece, Arabia, India, Corea, Kamtchatka, and Africa. Two remarkable peninsulas indeed, *In February, 1819, land was discovered by Mr. William Smith, Captain of an English brig, when his ship was in Lat. 62° 40° South, and Long. 60° West. he traced the coast for 250 miles, but it is yet to be ascertained whether this is an island of considerable size, or a part of a continent. It is by no means improbable that it may be connected with southern Thule, the most southerly part of Sandwich land seen by Captain Cook in 1775, and situated in 59. 30 S. lat. and 27° 30 W. Long. Desmarets, Encycl. Method. Géo. Phys. i. See Book ii. p. 53. Bacon. Nov. Organ. L. ii. Aphor. 27. Iucatan and Jutland stretch towards the north, but they BOOK consist only of plains and alluvial land. VII. But the general direction of the land is entirely different Direction in the two continents. In the new continent it extends from of the conpole to pole; while in the old the direction is more parallel tinents. to the equator; and if we examine only Europe and Asia, it is perfectly so. The longest straight line which we can trace upon the ancient continent, running it as much as possible over land, commences, according to Bergmann, under the 61st degree of north latitude, near the mouth of the river Ponaschka in the sea of Anadyr, and crossing over the town of Nargun, the lake of Aral, and the southern part of the Caspian Sea, passes near the Persian Gulf, and to the north of the straits of Bab-el-Mandeb; it then traverses Africa, following the course of the mountains of Lupata, or the spine of the globe, and terminates at the Cape of Good Hope. It is 148 degrees, or 2960 marine leagues in length.* It forms with the equator an angle of 65 degrees, and the parts of the continent, situate to the east and west of this line, are nearly equal. It is difficult to trace a similar line over the new continent. Bergmann makes it begin at the 60° north latitude, and at 265° longitude east of the island of Ferro. It continues, according to Buffon, to pass over Florida and the islands, to the mouth of the river La Plata. According to him it is one hundred and five degrees, or two thousand one hundred marine leagues in length, and makes an angle of sixty-eight degrees with the equator. According to the latest discoveries, this line ought to be prolonged ten degrees farther north; its length will then be 2300 leagues. But we cannot accurately represent the length of the new continent, except by a line containing many curves, in passing from the "icy cape" of Cook, through Mexico and Quito to Cape Horn. We shall then have a line of more than 3000 leagues in ex * Phys. Geog. I. 3-5. Comp. Buffon, Preuves de la Theorie de la Terre, Art. 6. The line drawn by Buffon passes above the Icy Sea. BOOK tent. This line will divide the continent into two very unequal parts. VII. If we were to suppose that the country round Baffin's Proximity of the pole. Bay, and that discovered to the north of Siberia, form an uninterrupted continuation of the continent of America, the new world must approach much nearer to the Artic pole than the ancient world. The frozen parts would thus be much more extensive, and the torrid regions much less than those of the old continent. The solution of the difference in the climates of the two great continents seems to depend upon this fact. The peculiarities of the isthmuses that divide each continent into two very unequal parts, (Suez being composed entirely of sand, while that of Panama is formed by rocks of granite and porphyry.) lead us to remark a very singular difference in those two great islands of the globe. The ancient world is in almost every part open to the advances of the ocean, and from the straits of Behring to those of Bab-el-Mandeb on the one side, and to those of Gibraltar on the other, the bays, gulfs, inland seas, &c. are, as it were, in a sort of equilibrium, at least with respect to numbers; while the mass of Africa is not penetrated by one single arm of the sea. The new continent, on the contrary, having only one considerable gulph, that of California, or the sea of Vermeille, on its western shore, presents on the opposite coast a chain of gulphs and inland seas; and when these are awanting, some immense river is found to supply the link. It is time, then, for geologists to cease from copying Buffon, when he would represent the two continents as exhibiting more breaks and inlets on the east side than on the west. Let us now pass from this view of the inequalities which the horizontal profile of our globe exhibits, to an examination of those which result from a perpendicular section. Mountains form the most considerable eminences on the surface of the earth, and have their descent more or less rapid. We must distinguish them from "plateaus," or upland plains, which consist of great masses of |