246 CLIMATE OF HIMALAYA. 



properly applied, may be considered as bounded at the south by 

 the plains of India, and on the north by the rivers Indus and 

 Burrampooter, which have their sources in the same spot, and 

 run one to the east, the other to the west, among lofty mountains, 

 till they enter the Indian flat country. Nearly in the centre of 

 this chain, in the most westerly part of Nepal proper, lies the 

 point of separation between the two great river systems, that of 

 the Indus and that of the Burrampooter, constituting a north and 

 south axis, wliich, when better known, will probably prove to be 

 the grand axis of Asia. 



From this centre the chain of the Himalaya extends to nearly 

 an equal distance in both directions, the central axis of the chain 

 being the line of water-shed between the streams which run 

 toward the plains of India on the south, and those which flow 

 toward the Burrampooter and Indus on the north. This line of 

 water-shed or central axis will, on inspection of a map, be seen 

 to be in general somewhat to the north of half way between the 

 two boundary lines of the chain, so that the distance from the 

 axis to the plains of India is greater than from the same place to 

 the northern rivers. The mean width of the whole chain may be 

 stated roughly to average about 150 miles, of which 90 are to the 

 south of the line of water-shed, and 60 to the north of it. 



From the central axis of the chain lateral ranges of mountains 

 run both to the north and to the south, stretching in the latter 

 direction as far as the plains of India, and separated from one 

 another by deep narrow valleys, which extend far into the inte- 

 rior of the mass of mountains. 



The number of lateral chains of the first class, which form the 

 line of division or water-shed between the basins of the great 

 rivers on the south side of the central axis of the Himalaya, is 

 about fourteen, separating from one another in a series from left 

 to right the waters of the Jhelum, the Chenab, the Beas, the 

 Ravi, the Sutlej, the Jumna, the Ganges, the Gogra, the Gandak, 

 the Kosi, the Teesta, and the Subhansheri. These great chains, 

 like the central axis, throw off lateral branches, which separate 

 from one another the difi'erent branches, by the union of which 

 within the mountains the great rivers are formed. 



The elevation of the central axis of the Himalaya is probably 

 at a mean about 1 8,000 or 20,000 feet ; it is nearly uniform at 

 about these elevations throughout a great part of the chain, but 

 gradually diminishes toward both ends. Like all mountain 

 chains, it presents alternations of high and low portions, the lower 

 parts, or passes as they are called, from their affording the means 

 of passage to travellers from one side to the other, being at the 

 upper extremities of the river basins. These passes are, with a 

 few exceptions, rarely under 17,000 or 18,000 feet. The lateral 



