Ml 



PLAINS. 



PLAINS. 



543 



northern border of the table-land, like the country around Bukhara 

 or Bucharia, lies at a very small elevation, probably not more than 

 1000 or 2000 feet above the sea, while the surface, as we know, and in 

 agreement with a previous statement in this article, descends on the 

 borders of the Caspian to 80 feet below that level. 



The table-land of Tibet itself u the summit of a great protuberance 

 above the general level of the earth's surface, of which the Kouenlun 

 and Himalaya are the north and south faces, while the other mountaiu- 

 langes and intervening valleys commonly marked on our maps of 

 Tibet are but corrugations of the table-land more or less strongly 

 marked. In its general relief, however, the table land is laid out hori- 

 zontally, at a mean elevation of 16,000 feet. The Indus and Brahma- 

 pootra rivers maintain a course along the length of the summit of the 

 table-land, and receive as they proceed the drainage of its entire 

 breadth, with the exception, first, of an occasional strip along its 

 southern edge, from which the water passes otf more or less directly to 

 the north through the Himalaya ; and secondly, of some parts chiefly 

 found in the northern half of the table-land, from which the water has 

 no escape, but Ls collected in lakes in depressions on its very summit. 

 The waters accumulated in these two streams are at length discharged 

 by two openings in the Himalayan slope, through the plains of Hindos- 

 tan, into the Indian Ocean. None of the drainage of the table-land, so 

 far as is known, passes in the opposite direction through the northern 

 slope. The waters of that slope itself exclusively flow down to the 

 plains of Yarkend. 



That portion of the table-land which forms a plain along the upper 

 course of the river Sutlej , we are informed by Major R. Strachey (to 

 whose rebearches, and those of his brother Captain H. Strachey, much 

 of our present accurate knowledge of these regions is due), " lies imme- 

 diately to the north of the British provinces of Kumaon and Ourhwal, 

 and is about 120 miles in length, ita breadth varying from 15 to 60 

 miles. IU surface, to the eye a perfect flat, varies in elevation from 

 16,000 feet along ita outer edges, on the south-west and north-east, to 

 about 15,000 feet in its more central parts, where it is cut through by 

 the river Sutlej, which flows at the bottom of a stupendous ravine, 

 formed out of the alluvial matter of which the plain is composed to a 

 depth of 2000 or 3000 feet, and at its west end even more." But 

 the table-land itself, it must be remembered, is a mountain-mass. 

 " The so-called plaint " of Tibet, Dr. Hooker remarks, " are the flat 

 floors of the valleys, and the terraces on the margins of the rivers, 

 which all flow between stupendous mountains," either those of the 

 northern and southern slopes or faces, or of the corrugations already 

 mentioned. 



In South America, contrasting with the lofty plains of Quito, of 



I'M de Bogota, ftc., are the llanoe and the plains of the Amazon ; 



while iii North America, the interminable prairies and the low swamps 



round New Orleans form a striking contrast with the Rocky Mountains 



anil the elevated plains of Mexico. 



Of Africa comparatively little is known ; but if the plains of Lower 

 Egypt and part of the Sahara are very low, there are high plains in 

 some of the mountainous regions. 



The great plateau or table-land of eastern Africa, according to Dr. 

 Beke, to whose continuation southward of Dr. Kuppell's investigations 

 we mainly owe our present knowledge of it, begins to the south of the 

 country of Taka, in about 15 of north latitude, where the anticlinal 

 axis between the Nile and the Red Sea rises rapidly till it attains an 

 elevation of 7000 or 8000 feet above the level of the ocean. At Halai, 

 at the summit of Mount Taranta, not more than eighteen geographical 

 miles from Zulla (the ancient Adule, recently, 1860, taken possession of 

 by the French government!, near Massowah, the edge of the table-hind 

 has an absolute elevation of 8825 feet, which gives a rise of 1 in 12'7, 

 equal to an angle of 4 30' with the horizon, to the eastern slope of the 

 table-land (or, as it may be more uorrectly called, in Dr. Beke's opiniou, 

 broad mountain-chain of Abyssinia). The western counterslope 

 towards the interior of the continent has a fall of 1 in 3437 only, 

 giving an inclination of 10' ; consequently, on a direct line from east to 

 west along the fifteenth parallel of north-latitude, the eastern slope of 

 the Abyssinian mountain-chain (or table-land) towards the sea is, to 

 the western counter-slope towards the Nile, as 29 to 1. But on a line 

 corresponding with the courses of the principal rivers from south-east 

 to north-west, the eastern slope has a rise of 1 in 38'83, equal to an 

 angle of 1 41', and the counter-slope of 1 in 460, or T 30", giving the 

 rtion of 11'8 to 1. In making this estimate, however, the rise of 

 the eastern slope is not taken from the level of the sea, but from that 

 of the river Hawash, which is the recipient of the waters of the eastern 

 elope as the Nile is of the western, and has itself an absolute elevation 

 of 2200 feet, at a point distant from the sea about ii'd miles. This, 

 again, gives a fall of about 1 in 650, equal to an angle of 6' 15", for 

 the eastward dip of the comparatively low-level country between the 

 Hawash and the Indian ocean. " As regards the counter-slope of the 

 Abessinian (Abyssinian) chain," Dr. Beke says, " it would seem that the 

 fall of the land towards the Nile in the western portion of it is con- 

 siderably greater than it is in the eastern ; so that the surface of the table- 

 land, or broad summit of the mountain chain, nior- nearly 

 vrl tlian if the slope were the snn mit. It is certain, 

 however, that the table-land nowhere forms an absolute level, and that 

 the general dip westward commences from its extreme eastern limit." 



This table-land, as the same geographer has shown, may, in the most 



general way, be compared with those of the Indian peninsula and South 

 America, but with this difference : the Western Ghauts in the former, 

 and the Cordilleras of the Andes, present their principal acclivities 

 towards the west, and thence slope gradually eastwards ; whereas the 

 African plateau rises abruptly on its eastern side, and has its western 

 counterslope towards the interior of the continent and the valley of the 

 Nile. Another point of difference is, that while the rivers which rise 

 near the western edge of the Ghauts and of the Andes take their 

 courses eastwards over the counter-slopes, at right augles with the 

 ] water-parting (commonly called the water-shed) [\VATI:R-SHED] or 

 nearly so, and discharge their waters into the ocean the streams 

 which have their sources at the water-parting of eastern Africa 

 flow in a general north-westerly direction, and fall into the Nile, 

 which skirts the lengthened western counter-slope. To these com- 

 parisons of Dr. Beke, it may be added that the general structure of the 

 African plateau resembles that of Tibet, described above. While 

 the principal direction of the latter, however, is from east to west, 

 its slopes being on the north and south the principal direction 

 of the former, as we have seen, is from north to south, the slopes 

 being on the east and west. But, mutatis muiandii, accordingly, the 

 resemblance between the great table-lands of Africa and Asia is 

 closer, we think, than that of the former to the elevated country 

 bounded by the Ghauts and the Cordilleras respectively. In this 

 comparison the Indus and the Brahmaputra correspond to the Nile 

 itself, while their main tributaries, the Juinna, Ganges proper, &c., 

 answer to the streams which fall into the Nile, as already mentioned, 

 from the south-east. The structural resemblance between the table- 

 lands of the two great continents is also very near in another respect, 

 allowing for the different distribution of dimensions. In the southern 

 extension of the African plateau, the rivers flow through deep trans- 

 verse valleys, forming openings through the eastern slope into the 

 low country at ita base, and thence into the ocean ; just as the waters 

 accumulated in the two great Indian rivers are discharged by openings 

 in the Himalayan or southern slope of the Asiatic table-laud, through 

 the plains of Hindostan, into the ocean. 



The African table-land, as a whole, may be described as a succession 

 of extensive undulating plains (like the corrugations and so-called plains 

 of Tibet, already mentioned), but dipping very gradually towards the 

 west and north-west, and intersected by numerous streams, which, 

 after a short course over the surface of the plateau, fall abruptly into 

 the deep-cut fissures or valleys just noticed, in which they soon reach 

 a depression of 3000 to 4000 feet below the general level of the table- 

 land. In addition to the irregularities produced by these valleys, the 

 uniformity of the surface is broken by loftier mountain-masses, which 

 in some parts of Abyssinia attain an absolute elevation of from 11,000 

 to 15,000 feet. The eastern edge of the plateau itself has been clearly 

 traced as far as the ninth parallel of north latitude, to which distance 

 it forms the water-parting between the basins of the rivers Nile and 

 Hawash. " How much further it extends southward," Dr. Beke 

 remarks, " our present knowledge scarcely enables us absolutely to 

 determine; but we may safely regard it as reaching beyond the 

 equator." The snowy mountains observed by Captain Short, and those 

 discovered by the missionaries Krapf and Kebmann south of the 

 equator, appear to be connected with the broad mountain range of 

 eastern Africa, of which the Abyssinian table-land forms the northern 

 portion. These are the " Mountains of the Moon " of the natives and 

 of the ancient geographer Ptolemy, which Dr. Beke has proved to be 

 thus a meridional and not an east and west chain, in which are the 

 sources of the Nile, and which form the eastern face of the table- 

 land in its southern extension. The continuation of this range was 

 crossed as far south as 7 30' south latitude by the recent travellers, 

 Captains Burton and Speke. Detailed information on the whole of 

 this subject, with maps and sections of the country, will be found 

 in Dr. Beke's work entitled ' The Sources of the Nile,' London, 1860; 

 from which, except as otherwise indicated, and with slight variations 

 of description, the preceding view of the African table-land has been 

 derived. 



Plains differ not only in their elevation, but in the horizontality of 

 their surface and general slope, and in the nature of their soil ; which 

 circumstances, together with their geographical position, influence their 

 climate and productions, and give to the most considerable among 

 them a particular character and physiognomy. It may be remarked 

 that the rocky and sandy plains belong almost exclusively to the hot 

 and temperate regions of the old world. The plains of America are 

 generally characterised by their gramineous covering or their vast 

 forests ; the Asiatic steppes by a twofold appearance, being in some 

 j parts studded with low saline plants, and in others, as in southern 

 Russia, Siberia, and Turkistan, covered with plants of the families of 

 the Oompositrf and Ltguminosce ; while the greater part of the European 

 plains are richly cultivated. 



We say such are the general characteristics, for there are plains of 

 similar character and physiognomy in very different and widely separated 

 regions of the world. The high land of the Campos Parexis, for 

 instance, in South America, is very similar in physiognomy to the 

 desert of Gobi in Asia. The Daiertui, near Coquimbo, are of the same 

 character as the Sahara. The Puata of Hungary resemble the savannas 

 of the New World ; and the pampas of Cordova are not unlike some 

 of the Siberian steppe*. 



