basins of the Yang-tse-Kiang and Hoang-Ho, the system at the same time diverges, fan-like, into the Yun-ling chain, between Tibet and China; the Nan-ling, between the basins of the Yang-tse-Kiang and Canton River; and the conjunct chains of the Ala-shan, In-shan, and Khingan, that trend in a north-easterly course, and form the southern wall of the great Mongolian desert. Altogether, the Eastern system is little known to geographers, either as regards the altitude of its mountain-chains, their physical features, their geological structure, or the minerals and metals they contain. 70. Commencing, in like manner, with the central knot of the Bolor, and stretching away in broad, more or less parallel, lines to Kamtchatka and Behring Strait, occurs the Northern system of Asia, flanked by the arid deserts of Tartary and Mongolia on the south, and descending by gradual stages to the great plain of Siberia on the north. The system embraces the Thian-shan or Celestial Mountains, ranging in an easterly direction for nearly 1400 miles, ascending in greater portion above the line of perpetual snow, but comparatively free from glaciers on account of the dryness of the air, and exhibiting throughout a number of volcanic cones, some of which, like Pe-shan and Ho-tscheou, are still active at elevations of more than 10,000 feet. In north-easterly continuation we have next the Altai Mountains, comprising several parallel ridges (the Tang-nu, Ulam-gom, and Dzungari), the Daurian, Yablonoi, and other little known ranges-all rising between Siberia and Mongolia, and separating the basin of the Amoor from those of the Yenesei and Lena. These closely associated ranges are said to have a mean elevation of from 5000 to 8000 feet; embrace several active and many extinct volcanoes; rise high in numerous points above the snow-line, which is there about 6000 feet; and culminate occasionally in peaks of 10,000 and 11,000 feet. Like other clustering ridges, the Altai and Daurian Mountains enclose a number of lakes, which find an outlet by narrow cross valleys, and terrace by terrace downwards to the larger rivers of Siberia. Still northward and eastward, but ramifying more irregularly, occur the Aldau, Stannovoi, and other chains that terminate in the volcanic system of Kamtchatka. These ranges are for the most part covered with snow (the snow-line sinking to 4500 and 4000 feet in Eastern Siberia), and contain numerous volcanic cones which, like Schiwelutch, 10,548 feet, and Klieutschewska, 15,955 feet, are still in active eruption. Indeed, the whole system is more or less volcanic-active cones, dormant craters, hot springs, gas-springs, and other kindred phenomena, marking the broad line of mountainous elevation that extends from Demavend on the Caspian to Klieutschewska in Kamtchatka. African Systems. 71. Of the African continent, to which we next turn, our knowledge is yet too limited to enable us to do more than merely advert to some of the more prominent mountain-regions, as likely embracing within their limits the elements of separate and independent systems. Our knowledge of Africa, however, is every year becoming more precise, and in no feature is it more interesting than that which reveals an interior of mountain and plain, river and lake, instead of, as at one time supposed, an arid and monotonous desert. In the extreme north we have the Atlas system, between the Mediterranean seaboard and the Sahara, and extending from Tripoli on the east to the Atlantic on the west. Geologically, it is evidently connected with the systems of southern Europe, and consists of three or four parallel ranges, which ascend stage by stage from the basin of the Mediterranean, and increase in altitude from east to west-being about 2000 feet in Tripoli, 4500 in Tunis, 7700 in Algeria; while in Morocco, Mount Miltsin, or Atlas, ascends to 11,400 feet, and Jebel Tedla to 13,000 feet, or above the line of perpetual congelation. Several secondary spurs proceed from the main ranges-one northward, and terminating in Cape Spartel at the Straits of Gibraltar, and several others southward into the desert plateaux of the Sahara. 72. Next in importance is the Abyssinian system, connected with and forming the lofty table-land (Amhara) of Abyssinia and upper Ethiopia-the gathering ground of the Atbara and Blue Nile. This plateau, which is 8000 feet above the sea-level, is supported and traversed by several clustering ranges of great elevation, and in many points above the line of perpetual snow, which is there about 14,000 feet. The two most persistent chains, under the names of the Samen and Taranta, strike in a northerly direction between the upper forks of the Nile and the Red Sea, and, skirting the shores of the latter, are prolonged into the lower hills of Egypt, which at the Gulf of Suez connect themselves with Sinai and the mountains of Syria. The culminating points in the Samen or upper range are Ras Detschen, 15,986 feet; Buahat, 15,000 feet; Abba Jarrat, 14,707 feet; and Umbattai and Beyeda, each 12,000 feet. In the Taranta or lower range, the heights descend from 9000 to 6000 and 5000 feet towards the Red Sea and the plain of Egypt. The system consists largely of granites, syenites, porphyries, and crystalline schists, and exhibits, in the higher range, that bold and rugged character distinctive of these formations. 73. In Western Africa the mountains are by no means well known, but under the Guinea system are usually embraced the Kong and Cameroon Mountains-the former rising between the Gulf of Guinea and the Niger, and generally averaging from 1200 to 3000 feet (Soracte, 1278, and Mount Ramel, 3200 feet); and the latter stretching eastward and unknown into the centre of the continent, and rising in many points to elevations of 4000, 6000, 9000, and even 13,000 feet. From the Cameroons, southward to Damara Land, the seaboard rises in terraces, backed by several ranges, of which very little is known; though the Campleda chain is said to attain an elevation of from 12,000 to 14,000 feet; the Mozamba, from 8000 to 10,000 feet; and the Omatako Berg, from 8000 to 9000 feet. 74. In Southern Africa the surface is occupied by a series of sandstone plateaux, resting on, and intersected by, granitic rocks, rather than characterised by a series of well-defined mountainchains-these flats (karoos) rising step by step, from south to north, at elevations of 2000, 4000, and 6000 feet above the sealevel. The steps of this ascent consist of rocky walls and flattopped mountains, ranging in an east and west direction, and intersected by narrow defiles (kloofs), which form the only means of passage from terrace to terrace; and these mountains (bergs) may, for the sake of reference, be denominated the Cape system. It consists, 1st, of the Zwellendam range, about 20 miles inland from the Cape coast, and stretching for nearly 200 miles in length, and attaining, in Table Mountain, an elevation of 3816 feet; 2d, the Zwarte or Black range, about 30 miles further north, and separated from the Zwellendam by the Kannaland Karoo; and, 3d, the northern chain, consisting of the Roggeveld, Nieuwveld, Winter Mountains, Sneeuwveld, Wittebergen, and other contiguous ranges, separated from the Zwarte hills by the great Karoo, and attaining heights of 4000, 6000, and even 10,000 feet, as in the Compass Berg in the Sneeuwveld or Snowy range. 75. From this point begins what may be termed the Eastern system, consisting of the Drakenberg or Quotlamba Mountains (10,000 feet), the Lupata Mountains (8000 or 10,000 feet), and other ranges that hold northward in parallel lines and increasing altitudes towards the equator, where several of the higher peaks (Kenia and Kilmandjaro, 17,000 and 20,000 feet) are said to be covered with perpetual snow. From the equator, in the direction of Abyssinia, would seem to extend high table-lands of 7000 or 8000 feet, which merge themselves, in all likelihood, into the highlands of upper Ethiopa, and form the great gathering-grounds of the Nile. Australasian and Polynesian Systems. 76. Of Australia and its mountain-chains it has been already stated (par. 57) that we know too little to enable us to arrange them into groups and systems, though one main ridge, extending along the eastern coast, from Torres Straits on the north to the extreme point of Tasmania on the south, would seem to indicate, a sameness and continuity of geological upheaval. This chain consists chiefly of granites and porphyries, intersected and overlaid in many places by recent volcanic products; is extremely rugged and inaccessible on the coast side, but slopes gradually towards the interior, and seldom exceeds 5000 feet in elevation— Mount Kosciusko, 6500 feet, and Sea-View, 6000 feet, in Australia, and Mounts Humboldt and Benlomond, 5520 and 5502 feet, in Van Diemen's Land, being the highest known points of elevation. Of the mountains that occur in the many islands of the Pacific and Indian Archipelago, it may be remarked that they are chiefly active volcanoes, and though often occurring in obvious linear connections, and of great altitudes (6000, 10,000, and 14,000 feet), they are merely to be regarded as chains in embryo, and as the rudiments of systems yet to be elaborated. The Aleutian Isles, the Japan and Kurile Isles, the Philippine and Molucca Isles, the islands of India and Australasia, the Sandwich Islands, the Society Isles, and Marquesas-all form volcanic groups and series of evident central and axial connections; and their results on the geography of future ages cannot fail to be as marked and decided as the influences of the Andes or Alps are on the physical features of the present day. (See Map of Volcanoes.) American Systems. 77. Having reviewed the mountain-systems of the Old World, we now turn to those of the New, where the arrangements are altogether on a simpler and more uniform plain. In North America we have first the Eastern, Appalachian, or Atlantic system, so called from its general proximity and parallelism to the Atlantic seaboard. It separates the waters that flow eastward into the Atlantic from those that flow westward into the basins of the Mississippi and St Lawrence; and though trending in one continuous direction from the St Lawrence to the Gulf States, may be said to consist of two divisions-the Blue Ridge, Shenandoah Ridge, and Alleghany on the south, and the Green and White Mountains on the north-sepa rated from each other by the narrow cross-valley of the Hudson. In length the system is nearly 2000 miles, has an average breadth of 100 or 130 miles; and though its mean altitude is only about 2500 feet, it yet ascends in Mount Washington in New Hampshire to 6652 feet, in Black Mount between Tennessee and Carolina to 6420 feet, and in Mount Katahdin in Maine to 5360 feet. In the northern section of the system, the ridges of the Notre Dame, the Green, White and Adironbeck Mountains are more or less irregular and interrupted; but in the southern, the Alleghanies consist of several closely parallel chains of great continuity, though frequently cut across by ravines and river-courses. Geologically, the system consists chiefly of the older or palæozoic rocks, flanked on both sides by an extensive development of carboniferous strata; and its eastern slopes comprise some of the finest and most diversified country in the American Union. Separated from the preceding system by the valley of the St Lawrence, but still trending in the same general direction to the northern shores of Labrador, occur the Wotschish and Mealy Mountains, which, though seldom exceeding 1400 or 1600 feet in height, are yet, from their boreal position, for the most part covered with perpetual snow. The following are the culminating points of this Eastern or Atlantic system :— 78. Interiorly and beyond these eastern ranges the country is one immense plain till we come to the Western or Pacific system, which, under the familiar name of the Rocky Mountains, stretches in several more or less connected ranges form the Isthmus of Panama to the shores of the Arctic Ocean. This extensive system, which after all is but the northern prolongation of the great backbone of the New World, consists of two main ranges-the Pacific or Oceanic, skirting the western seaboard from Cape Lucas in California to Cape Elizabeth in Russian America—and the Rocky Mountains proper, extending in double and sometimes in treble chains from Panama to the Arctic shores. The former of these ranges forms the watershed between the Pacific on the west and the Colorado, Columbia, and Colville on the east. Though continuous as one great range, it consists of several members, such as the Sierra S. Lucia and Sierra Nevada in California, whose highest |