780 On the Physical Geography of the Himalaya. [Aug. 



continue the ascent to the base of the true mountains, but troughwise, 

 or with a concave dip ; and, lastly, that the Dlnins are contained 

 between the low sandstone range and the base of the true mountains. 

 The Tarai is an open waste, incumbered rather than clothed with 

 grasses. It is notorious for a direful malaria, generated (it is said) by 

 its excessive moisture and swamps — attributes derived, 1st, from its low 

 site, 2nd, from its clayey bottom, 3rd, from innumerable rills percolating 

 through the gravel and sand of the Bhaver, and finding issue on the 

 upper verge of the Tarai (where the gravelly or sandy debris from the 

 mountains thins out), without power to form onward channels for their 

 waters into the plains. The forest is equally malarious with the 

 Tarai, though it be as dry as the Tarai is wet. The dryness of the 

 forest is caused by the very porous nature of that vast mass of diluvial 

 detritus on which it rests, and which is overlaid only by a thin but rich 

 stratum of vegetable mould, every where sustaining a splendid crop of 

 the invaluable timber tree (Shorea robusta), whence this tract derives 

 its name. The sandstone range is of very inconsiderable height, though 

 rich in fossils. It does not rise more than 3 to 600 feet above its 

 immediate base, and is in some places half buried (so to speak) in the 

 vast mass of debris through which it penetrates.* The Dhuns are as 

 malarious and as dry as the Bhaver. They are from 5 to 10 (often 

 less, in one instance more) miles wide, and 20 to 40 long, sloping from 

 either side towards their centre, and traversed lengthwise by a small 

 stream which discharges itself commonly into one of the great alpine 

 rivers ; thus the Raputi of Chitwan-mari falls into the Gandak, and 

 that cf Bijaypur-mari into the Cosi. The direction of the Maris or 

 Dhuns is parallel to the ghat line of the snows, and their substratum 

 is a very deep bed of debris similar to that of the Bhaver, but deeper, 

 and similarly covered by a rich but superficial coating of vegetable 



* The low range which separates the Dhuns and Tarai, on the high road to 

 Kathmandu, consists almost wholly of diluvium, rounded pebbles loosely set in 

 ochreous clay, such as forms the great substratum of Dhun and Bhaver. The 

 sandstone formation only shows itself where the rain torrents have worn deep gul- 

 lies, and it there appears as white weeping sand imperfectly indurated into rock. 

 Anthracite, shale, loam, are found in this quarter, but no organic fossils, such as 

 abound to the westward. Herbert assigns the Siwaliks to the new red formation of 

 geologists. But if I understand Lyell rightly, that formation is inimical to fossils. 

 Is there any mistake as to the technical class of rocks ? 



