310 Br T. Thomson on the Climate mid 



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 dif- 

 ferent 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 18,000 or 20,000 feet ; it is nearly uniform at about 

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

 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 travel- 

 lers from one side or 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 chains, starting from 

 the more elevated portions of the central axis between the passes, 

 gradually diminish in elevation as they approach the plains of 

 India, not, however, with any exact uniformity of progression, for 

 it is not unfrequent to find them rise into lofty peaks considerably 

 more elevated than any known part of the central axis. The greater 

 part of the giant peaks, which rise to an elevation of 26,000 or 28,000 

 feet, are situated in this manner, not on the central axis, but to the 

 south of it ; it is, however, by no means improbable that masses of 

 equal elevation, not yet measured or observed, may occur behind 

 them, it being unquestionable that the general elevation of the country 

 continues to increase as we advance to the north, and that we have 

 not yet (except in one place) attained to any point from which a de- 

 scent is commenced towards the northern plains. 



The direction of the principal lateral chains and of their included 

 valleys, is, on the whole, perpendicular to the main axis, but with an 

 inclination from the centre ; those on the extreme east inclining to 

 the eastward, while those on the extreme west have a very westerly 

 direction. There are certain anomalies in the courses of the rivers, 

 particularly at the north-west extremity of the chain ; which, how- 

 ever, may be overlooked in a view so general and cursory of these 

 rivers, as must necessarily be taken on the present occasion. The 

 most marked of these peculiarities may be observed in the course of 

 the Sutlej, which runs for a very considerable part of its course nearly 

 parallel to the Indus before it turns toward the plains, thus sepa- 

 rating the western part of the Himalayan chain, almost from its 

 very origin, into two branches, one of which separates the Sutlej 

 from the Indus ; the other to the south of, and nearly parallel to, 



