greatest Heights of the Hhnulayah and Upper Peru. 37 



volcano of Arequipa has a height of more than 18,000 feet, 

 and yet it is only on the southern summit that there is a trace 

 of snow. . 



We see therefore, that also in the Peruvian Cordillera, at 

 those points where great mountain masses include extensive flat 

 tracts, the limit of eternal snow ascends much beyond the usual 

 heights, and corresponds with that in the northern Himalayah, 

 where still larger mountain masses are grouped together ; and 

 that there also, that is in the Cordillera, isolated and extremely 

 remarkable exceptions occur, although a very large po: ;:on of 

 the range of the Cordillera, especially th.e part in southern Bo- 

 livia, where the great volcano of Gualatieri is situated, is still 

 quite unknown. 



But in the Himalayah, there are also a great many places 

 where the snow limit ascends far above 17,000 feet ! All thi& 

 taken together, leads to the conclusion, that the dome-like curve 

 of the line of eternal snow, when drawn so as to include the whole 

 earth, must, according to the observations we possess, be in the 

 highest degree uneven. We could, it is true, calculate a curve 

 from the relative position of the sun and the earth, where the 

 temperature would be that of the freezing point ; but this does^ 

 not coincide with the snow line, and besides, would not coincide 

 with the points of the snow line as actually observed on the 

 earth. 



Having thus shewn a great agreement in the height of the 

 snow line of the two highest and most extensive masses of moun- 

 tains, viz. of the Peruvian Cordillera and the Himalayah, I 

 shall now compare the heights to Avhich vegetation reaches oil 

 tljese mountains. 



In the year 183], Captain Hall observed on Chimhorazo, at 

 a height of 17,000 feet, several beautiful alpine plants in flower; 

 and I have shewn that even the shrubby vegetation, therefore 

 the region under that of alpine plants, occurs in the high moun- 

 tains of southern Peru at a height of 15,500 to 16,000 feet. In 

 the Himalayah, on the contrary, and that only in north-eastern 

 Kunawar, the vegetation extends to 16,000 feet ; but I know no 

 example there where the alpine plants pass that elevation, as, 

 forcxample, they do on Chimborazo, on the volcano of Arequipa, 

 and several other places in the Peruvian Cordillera. At a 



