1 66 PREHISTORIC E UR OPE. 



500 feet. In many places, he says,at reaches a thickness of 

 1500 feet. It extends inland over all the high plains, from the 

 alluvial flats of the Gulf of Tshili over the Taihhang-shan 

 Mountains up to plateaux 1800 metres high, and even to an 

 elevation of 2400 metres above the sea in the Wu-tai-shan 

 Mountains in Northern Shansi. It stretches south of the hilly 

 grounds beyond the valley of the Yangtze, and up that valley 

 in a westerly direction for an unknown distance. It can be 

 followed up the. course of the Han to the watershed of that 

 river, and it is known to extend up the valley of the Yellow 

 Eiver without interruption into the province of Kansuh. This 

 enormous deposit, according to Eichthofen, is solely the result 

 of atmospheric waste and wind-action ; and he has brought 

 forward a large body of interesting and important evidence 

 to prove the correctness of his theory. 



The winds that blow across a great continent like Asia are 

 to a large extent drained of their moisture by lofty mountains, 

 elevated plateaux, etc., before they can reach certain regions in 

 the interior, which as a consequence become desiccated and 

 deprived of springs and rivers. The materials which are the 

 result of atmospheric waste, and which in well-watered regions 

 would eventually find their way to the sea, are allowed to 

 accumulate upon the surface of such dry desert areas, and the 

 rocks, bared of their vegetable covering, crumble away, more or 

 less rapidly, to loose grit and sand. Occasional rains and torrents 

 help to carry the products of superficial waste down to the lower 

 grounds, where they become still further reduced in size, and are 

 sifted by the action of the wind. Vast quantities of dust and 

 fine sand are thus produced, and during storms these are swept 

 up and scattered over extensive areas, and in this manner 

 adjoining territories, such as the grassy steppes, are ever and 

 anon receiving increments to their soil. The finely-sifted 

 material thus obtained is highly fertile, and offers no impedi- 

 ment to the growth of the grasses, which, on the contrary, con- 

 tinue to flourish ; and so every addition brought by the winds 

 becomes in this way fixed, and the Steppe -formation goes on 



