THE HUMAN SPECIES. 119 



several species of land mammals, common to both continents, 

 attests a facility of passing from one to the other, and a pas- 

 sage to have been effected by several of them on the ice. 



While the foregoing statements sufRcieiitly demonstrate a 

 continued declination of the south and east coasts of Asia, the 

 case appears entirely reversed, from the lofty central mountain 

 hinge northward to the shores facing the Arctic Sea. Chinese 

 documents of remote antiquity report the land to have termi- 

 nated at no great distance beyond the mountain chain of North- 

 ern Tahtary;* skeletons of whales having been found 800 

 miles inland, up the Lena. 



The enormous loads of debris which some rivers, amongst 

 the largest in the world, incessantly pour forth from the 

 great central chains of Asia, convert them, during the melt- 

 ing of the snows, for a considerable period to the breadth 

 of marine straits, and carry away hills, banks, and forests, in 

 their course ; and constantly shift the soil in such a manner, 

 that, speaking of a more elevated basin, Cochrane remarks : — 

 "It is but twenty years since the present centre of the river 

 Selinga was the centre of the city Selenginsk." The Obi, 



* According to the Chevalier Paravey, north-eastern Asia was still 

 rising within the last two centuries. The shadow of a gnomon, set up in 

 1260, by order of Kobi-lay, emperor of China, proves that the northern 

 coast then ranged between the 63d and 64th degrees of north latitude ; 

 whereas, now it is above 70 degrees. — Memoir read at the Geographical 

 Society, 8th Feb., 1S41 ; see Biblioth. Orientate d'Herbelot, t. iv., p. 171 ; 

 Hedenstrochm. M. Arago remarks that the ice has greatly accumu- 

 lated in the Arctic seas within the latter centuries, and rendered navi- 

 gation round the polar extremity of Nova Zembla totally impracticable, 

 although the foregoing travellers maintain that the cold in eastern Siberia 

 decreases sensibly ; and this opinion is in perfect accordance with the 

 gradual rising of the polar shore, for that must increase the power of the 

 sun's rays very considerably, on the oblate spheroid surface of the Arctic 

 Circle. Strahlenberg notices the entire hull of a keeled ship being found in 

 the Barabinsk, between six and seven hundred miles from the sea. Wran- 

 gel observed drift-wooc above the highest sea level, upwards of 50 versts 

 inland, and other phen mena of 7isings of the surface. See Reise. 



