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Sketch of the Climate and Vegetation of the Himalaya, By 

 Thomas Thomson, M.D., Assistant Surgeon in the 

 H.E.I.C. Service, Bengal Establishment.* 



The great range of the Himalaya, when taken in conjunction with 

 the still more elevated mountains behind, which are in nowise dis- 

 tinguishable from it, constitutes the most stupendous mass of moun- 

 tains in the world, not only from containing the highest peaks, but 

 also, and still more remarkably, as presenting by far the greatest 

 area of elevated land. 



This gigantic mountain mass lies to the north of the great plain 

 of India, from which it rises on the whole very abruptly. It has a 

 direction very nearly from east to west, its west extremity is, how- 

 ever, a little more northerly than the east, the latitude rising from 

 26° at the east, to 33" at the west extremity. 



The mountain-chain to which the name of Himalaya is most pro- 

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

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

 pooter, 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, which, 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 Bur- 

 rampooter and Indus on the north. This line of water-shed or cen- 

 tral axis, will, on inspection of a map, be seen to be in general some- 

 what 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 160 

 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 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 interior of the mass of 

 mountains. 



Ft<i« Piroceedings of the Pbilosophlcal Society of OlAsgow, 1851. 



