the two hemispheres is not less remarkable. Of the whole land, about four-fifths is situated in the northern hemisphere, and the remaining one-fifth in the southern. 29. The general features of the Old and New Worlds differ remarkably. In the Old World, the general direction of the land, and of the great mountain chains, is from west to east, almost parallel to the equator; while in America their general direction is from north to south, along the meridian. Thus, the Alps in Europe, and the four great mountain ranges in Asia, stretch from west to east; while, in America, the Rocky Mountains, the Western Cordilleras, and the Andes, range from north to south. The coast line, again, of the Old World is very much more indented and broken than that of the New. In one respect only, under this head, do the two worlds agree the promontories in both, whether large or small, as, for example, South America, California, Greenland, Florida, Scandinavia, Italy, Greece, Arabia, India, Corea, Africa, with scarcely an exception, point to the south. 30. Even a first glance over any considerable territory discovers an exceedingly uneven surface. The land is elevated into mountains; depressed into valleys; it stretches out into plains near the level of the sea; it rises high above this level and expands into extensive table-lands. The whole surface is elevated more or less above the general level of the ocean; with the remarkable exception of a vast plain in Central Asia, which is more than 100 feet below the surface of the Black Sea. 31. Plains, with only moderate undulations, are found in every region of the world. One of the most extensive is that which spreads from the confines of the Frozen Ocean, chiefly through Russia, to the shores of the Euxine and Caspian. Here it is interrupted by the Oural chain of mountains. But on the eastern side of these there spreads the great plain of Northern Asia, in a north-easterly direction, bounded on the south by the Altaian chain, until it almost sweeps the coast of the North Pacific Ocean. The surface of much of these two great plains is fertile; some of it is covered with heaths or swamps, producing a stunted vegetation; a considerable part is shrouded in dark pine forests. 32. Deserts. The largest and most remarkable desert in the world is the Sahara, or great African Desert. It is, as its name imports, a sea of sand. It spreads like an ocean between the ridges of Mount Atlas and the parallels of the Senegal and the Niger, and from the Atlantic to the narrow valley of the Nile, covering a superficies of more than two millions of square miles. Like the sea, its surface, when agitated by the winds, rises in huge towering waves, which move with great rapidity, and sometimes overwhelm whole caravans of travellers. Indeed it would be impassable, even by camels, "the ships of the desert," but for the oases, or fertile spots, which are met with here and there, the tufted isles That verdant rise amid the Lybian wild. 33. The narrow valley of the Nile and the Red Sea are all that separate the African deserts from those of Asia. The deserts of Arabia, Syria, and Persia, are saharas on smaller scales. One distin guishing feature of the great desert in Persia is, that many parts of its surface are covered with saline incrustations: hence it is called the Great Salt Desert. These desert regions are remarkably deficient in considerable rivers: except the Nile, the Euphrates, the Indus, and Oxus, there are no large rivers in a region which embraces almost a fourth part of both Africa and Asia. 34 In Central Asia, which consists of an immense plateau or table-land, is the great desert of Cobi, about 1200 miles long, and from 500 to 700 miles broad. Through the middle of this, for its whole length, extends the Shamo, or sand sea, varying in breadth from 150 to 250 miles. The great elevation of this desert, and its comparative distance from the equator, preserve it from the scorching heats of the saharas of Africa and Arabia. Some of its plains, says Humboldt, are covered with herbage; others produce only evergreen saliferous plants, with fleshy and jointed stems; but a greater number glitter from afar with a saline efflorescence, that crystallizes in the semblance of lichens, and covers the clayey soil with scattered patches like new-fallen snow. 35. In America there are immense plains and extensive deserts. The vast tract included between the Rocky and the Alleghany mountains on the one hand, and the Gulph of Mexico and the Great Lakes on the other, may be regarded as one immense plain. The southern portion of this vast plain is exceedingly fertile; but the western and north-western parts of it abound in deserts, savannahs, and prairies. The savannahs and prairies are generally covered with a species of coarse grass, which often grows to the height of a man; and they abound in wild animals, as the bison. In the western part of the plain, between the Ozark and Rocky Mountains, is the great American Desert; which bears a strong resemblance, in the portion traversed by the Platte River, to the barren and saline steppes of Asia. A great portion of the plain of the Missisippi is exposed to wide periodical inundations from that river: the alligator and the bison are the alternate lords of this extensive region. The other vast plains of America are the basins of the Amazon, La Plata, and the Orinoco. The llanos of Venezuela, extending from the mouth of the Orinoco to the foot of the Andes, are open solitudes,-motionless, gloomy, awful,-with a scanty soil, destitute of trees, but covered with a luxuriant herbage, in consequence of periodical inundations, which convert this part of South America into inland seas :- amid the turbid waters of which, says Humboldt, may be seen herds of wild cattle and of horses, swimming from one gradually diminishing island to another, in search of food, or escaping from the attacks of the jaguar, to become the prey of the alligator, or perhaps to be stunned by the strokes of the electric gymnotus. The pampas of Buenos Ayres stretch out to an immense extent between the Paraguay River and the Andes, presenting to the eye interminable plains, with a surface often as unvaried as the ocean. 36. Mountains.-Mountains are certainly the most striking features of the surface of the globe, and play an important part in the general economy of nature. They modify climate; produce much variety in the vegetable world; attract the waters of the sky, and disperse them over the face of the whole earth, under C the beneficent forms of rain and snow, of springs and rivers. They break up the otherwise monotonous surface of the earth, disclose her mineral treasures, and impart an unspeakable glory and charm, through every gradation of grandeur and beauty, to her boundless landscapes. Mountains exhibit numerous and picturesque varieties. The loftiest peaks generally consist of naked rocks, whose nature determines the outline. At one time the mountain shoots up enormous crystals, in bare and savage grandeur; while, in other instances, vast masses are crowned with rounded summits, rising into the air with tranquil majesty, and looking down, like throned kings, upon the plains below. Mountains of less elevation are often equally picturesque; and while generally destitute of the sharp angles and needle-points of the former class, sometimes present in their regular gradations a vast amphitheatre not less imposing. Beneath these rank hills; sometimes precipitous, but usually sloping away in gentle declivities, and losing themselves in the surrounding plains. Volcanic mountains are mostly conical. Basaltic mountains display immense pillars and causeways; as the Giant's Causeway in Ireland. 37. In general, the bases of a series of neighbouring mountains run into each other, constituting a chain. Chains of mountains are seldom solitary. Sometimes we find a central chain with secondary lines branching off from it; sometimes a collection of chains of equal rank; and in a few instances, as the Cordilleras of America, a series of chains running parallel to each other, for thousands of miles, in one constant direction. The following are the estimated |