288 On the Snow-line in the Himalaya. [April, 



limit of perpetual snow on the southern declivity of the Himalaya chain 

 is 2030 toises (13,000* feet English) above the level of the sea ; on the 

 northern declivity, or rather on the peaks which rise above the Tartarian 

 plateau, this limit is 2600 toises (16,600 ft.), from 30£ to 32° of Lati- 

 tude, while under the equator in the Andes of Quito it is 2470 toises 

 (15,800 ft.). I have deduced this result from the collection and com- 

 bination of many data furnished by Webb, Gerard, Herbert, and Moor- 

 croft. The greater elevation to which the snow line recedes on the 

 Thibetian declivity is the result conjointly of the radiation of heat from 

 the neighbouring elevated plains, the serenity of the sky, and the infre- 

 quent formation of snow in very cold and dry air" (Cosmos. Trans. 

 T. l.p. 363. Note 5). 



The portion of the Himalaya to which allusion has most generally 

 been made, in treating of the snow line, is that which lies between the 

 north-western frontier of Nipal and the river Sutlej, and it is solely to 

 this part of the chain that my remarks are intended to apply. It ex- 

 tends from about the 77th to the 81st degree of east longitude, and its 

 entire breadth, from the plains of India on the south, to the plains of 

 Tibet on the north, is about 120 miles. The mountains on which per- 

 petual snow is found, are confined within a belt of about 35 miles in 

 width, running along the northern boundary of the chain, and they all 

 lie between the 30th and 32nd degree of north latitude. 



If we now examine the structure of the mountains more closely (vide 

 sheets 47, 48, 65 3 and 66 of the Indian Atlas), we shall find that from 

 the sources of the Touse, (Long. 78° 30'), to those of the Kali (Long. 

 81° 0'), a space which includes the provinces of Garhwal and Kumaon, 

 all the great rivers, viz. the Bhagirati, Vishnu-ganga, Dauli (of Niti), 

 Gori, Dauli (of Darma) and Kali, run in directions not far from perpen- 

 dicular to the general direction of the Himalaya. Further, that they 

 are separated one from another by great transverse ranges, on which all 

 the highest of the measured peaks of this region are to be found. It 

 will also be seen that the sources of these riversf are in the main water- 

 shed of the chain, beyond which a declivity of a few miles leads directly 



* The reduction of toises into English feet is every where given to the nearest 

 hundred only. 



f I mean the most distant sources of the tributaries, for several of the rivers that 

 I have mentioned, nominally end in glaciers to the south of the water-shed. 



