252 ANNUAL OF SCIENTIFIC DISCOVERY. 



pointed out that the elevated region known as Tibet formed the sum- 

 mit of a great protuberance above the general level of the earth's 

 surface, of which the two mountain chains, known as the Himalaya 

 and Kouenlun, were nothing more than the north and south faces, 

 having no special existence apart from the general mass. The plains 

 of Northern India extend along the entire southern edge of the Hima- 

 laya, over about 500,000 square miles, nowhere exceeding in elevation 

 1,200 feet above the sea. From these rise the mountains suddenly, 

 and in a well-defined line. The exterior range, called the Siwaliks by 

 Dr. Falconer and Col. Cautley, is of no great elevation, hardly exceed- 

 ing 3,000 feet. The characteristic tracts of swamp and dry forest that 

 occur along its southern face, known as Tarai and Bhabar, and the 

 longitudinal valleys called Dun, along its northern slope, were de- 

 scribed. Immediately above these rise the first ranges of the great 

 mountain region that extends to the north, over a breadth of upwards 

 of 200 miles. The loftiest peaks, some of which exceed 28,000 feet in 

 height, are usually found along a line of 80 or 90 miles from the south- 

 ern edge of the chain, which, in Kumaon, neither is coincident with 

 the water-shed, nor forms a continuous ridge, but is broken up into 

 groups, separated by deep gorges, and connected by transverse spurs 

 with the water-shed range that runs 20 or 30 miles further to the 

 north. On crossing this water-shed, which forms the boundary be- 

 tween Tibet and the British Provinces, the traveller finds himself, not 

 without astonishment, on a plain of 150 miles in length, and 30 or 40 

 in breadth, the elevation of which varies from 16,000 feet along its 

 southern edge, to 14,500 feet in its more central parts, where it is cut 

 through by the river Sutlej. It is everywhere intersected by stupen- 

 dous ravines, that of the Sutlej being nearly 3,000 feet deep, which 

 are furrowed out of the alluvial matter of which the plain is composed. 

 The mountains that bound this plain to the north hardly enter the re- 

 gion of perpetual snow ; the famous peak of Kailas, which is nearly 

 22,000 feet in altitude, being the highest point. In regard to the 

 geology of this region, it appears that, from the Siwalik range, which 

 was before known to be of tertiary age, the mountains are formed of 

 metamorphic rocks, until we pass the line of greatest elevation. We 

 then again find fossiliferous rocks, which form a regular sequence from 

 the lower Silurian to the tertiary formation. Fossils from all of these 

 beds have been collected and brought to this country by Capt. Strachey. 

 It is of the tertiary beds that is composed the great plain already 

 described, and in them have been found fossilized remains of elephant 

 and rhinoceros at an elevation of between 14,000 and 15,000 feet above 

 the sea. Froni^i general consideration of these circumstances, it was 

 inferred that the present wonderful development of the Himalaya and 

 of the elevated regions of Tibet dates no further back than the tertiary 

 period ; being, in fact, one of the most recent changes that the sur- 

 face of the earth has undergone. Glaciers abound in all parts of the 

 mountains covered with perpetual snow, descending as low as 11,500 

 feet. The snow-line, the height of which has given rise to much dis- 

 cussion, was stated to descend to about 15,500 on the southern face of 

 the Himalaya ; while it was pointed out that, as we advance to the 



