INTRODUCTION. 



11 



central tract from which all the great rivers of Asia radiate ; 



on the Indian side their drainage being effected by the three 



great systems of the Indus, Ganges, and Brahmapootra. The 



most remarkable feature about the Himalayahs is a line of 



snowy peaks which may be considered as forming the axis 



of the chain, a plain supported on which, from Cashmeer to 



the Delta of the Ganges, would be elevated upwards of 20,000 



feet above the level of the sea. Between this central range 



and the plains of Hindostan there is a belt of mountains of 



minor altitude, with an average elevation of about 7,000 or 



8,000 feet. These intermingle with the Sewahk range, which 



rises abruptly from the plains.^ 



***** 



The great chain of the Himalayahs rises in a ridge with an 

 abrupt steep face against the plains of about 6,000 feet in 

 height ; there is then a slope from the crest of the ridge 

 towards the north. This is the general character of the 

 Himalayahs. The mountains on the side of the snowy range 

 consist of a series of nearly parallel ridges, with intermediate 

 valleys or hoUows. They throw off spurs in all directions 

 into the hollows, forming subordinate valleys. There is 

 nothmg like table-land (perhaps in the whole of the moun- 

 tains, with the exception of Nepaul), and the valleys are rather 

 broad, wedge-shaped chasms, contracted at the bottom to a 

 mere water-course, than anything else ; in fact, the ridges and 

 intermediate valleys, as a general law, form a series of salient 

 and re-entering angles, as seen in the sketch (fig. 1, p. 19). 

 In consequence, the quantity of level or nearly level ground to 

 be met with is most inconsiderable. From the dip or slope 

 being towards the north, and the abutment to the south being 

 steep, the great mass of vegetation has a northern exposure, 

 and the southern faces of the moimtains are generally naked. 



The formations are primary ; the first towards the plains 

 consist of vast strata of limestone, lying on clay-slate, crowned 

 by slate, greywacke, or sandstone. Beyond the limestone 

 tract, gneiss, clay-slate, and other schistose rocks, occur. 

 Granite, so far as I know, is not found in the outer ridges. 

 It occurs in the mountains nearer the snowy range. I have 

 not gone so far, and have not yet seen granite in situ. 

 The igneous rocks, which have been concerned in the up- 

 heavement of the outer tracts, are of the green-stone trap 

 series, and are very generally met with in dykes intersecting 

 and rising through the regular strata. The formations 



' The manuscript here breaks off ab- 

 ruptly. The three paragraphs which fol- 

 low are extracted from an essay by Dr. 

 Falconer, ' On the Aptitude of the Hima- 



layan range for the Culture of the Tea 

 plant' (Journal of the Asiatic Society, 

 April, 1834).— [Ed.] 



