GENERAL FEATURES OF THE EARTH. 27 



with a striking difference in the immense shore-plain between 

 them and the sea. 



The sketch (fig. 20) presents the general features to the eye. 

 At a, there is the elevated land of India ; between a and b, the low 

 river-plain at the base of the Himalayas ; at b, the Himalayas ; b to 

 c, Plains of Thibet ; c, the Kuen-Luen ridge ; c to d, Plains of Mongolia 

 and Desert of Gobi ; at d, the Altai ; d to n, the Siberian plains. 



The interior region of the continent in its eastern half is the 

 plateau of Gobi and Mongolia, which, at 4000 feet, is low compared 

 with the mountains in front and rear. More to the westward the 

 region c, d becomes intersected by the lofty Thian-chan Eange. 

 Still farther westward the surface declines into the great depression 

 occupied by the Caspian and Aral, part of which is below tide-level 



(I 19)- 



The interior drainage-system for Asia is without outlet. The 

 Avaters are shut up within the great basin, the Caspian and Aral 

 being the seas which receive those waters that are not lost in the 

 plains. The Volga and other streams, from a region of a million 

 of square miles, flow into the Caspian. 



The Urals stand as a partial barrier between Asia and Europe, 

 parallel nearly with the mountains of Norway. 



Europe has its separate system of elevations and interior plains ; 

 but it is not necessary to dwell on it here. 



The great continental mass accords with the law stated : — high 

 borders proportioned in the case of each to the extent of the bor- 

 dering oceans, and a general basin-form. 



31. (3.) Africa. — Africa has the Atlantic on the west, the larger 

 Indian Ocean on the east, with Europe and the Mediterranean on 

 the north, and the South Atlantic and Southern Ocean on the 

 south. Its system of structure has been well explained by Pro- 

 fessor Guyot. As he has stated, the northern half has the east- 

 • and-west position of Asia, and the southern the north-and-south 

 of America ; and its reliefs correspond with this structure. The 

 Guinea coast belonging to the northern half projects west in front 

 of the South Atlantic, and is faced by the east-and-west Kong 

 Range ; and opposite, on the Mediterranean, there are the Atlas 

 Mountains, one peak of which is 11,000 feet high, — although the 

 ridges are generally much lower. The two thus oppose one 

 another, like the Himalayas and Altai. The southern half of the 

 continent has a border mountain-range the most of the way along 

 the west and south. On the latter, which has a length of 700 

 miles, there are three or four parallel ridges, and some of the 

 peaks are 4000 to 7000 feet high. Up the eastern coast there is 



