TEANSACTIONS OF SECTION B. 615 



that the outer border of our plateau north of the Pamir is formed by the terminal 

 spurs of the Thian Shan. It is to be remembered also that the Indian Caucasus — 

 which does not concern our plateau directly enough to fall within this address — 

 probably joins the Pamir. In general terms, the convergence of mountain ranges 

 on the Pamir renders it geographical]}' the most important position in Asia. The 

 uniustructed iVsiatics have evinced a hazy admiration of its grandeur by calling it 

 ' the roof of the world.' The comparatively instructed Europeans have revered it 

 as the soiu'ce of the classic O.xus and as fraught with political considerations. Un- 

 less further discoveries shall alter existing information, we may expect that com- 

 pletely informed geographers will consider that this Pamir is the mother of 

 mountains, that other ranges are to it as the branches are to the root, and that here 

 if anywhere is the true boss of the Asiatic shield. 



In the second place, the vast surface of our plateau, though almost uninter- 

 ruptedly environed by its rocky walls, presents an extraordinary series of elevations 

 and depressions. In the heart of the plateau there is the depression known to 

 geographers as the Western Gobi, sometimes called the Tarim basin. Within this 

 there is the Lob Lake or Lob Nor, truly an inland sea into which the waters of 

 several rivers ultimatelj- flow, finding no vent towards the ocean. The total length 

 of the Tarim river, with its affluents debouching into Lob Nor, cannot be less than 

 800 miles. This curious and interesting lake is not more than 2,000 feet above 

 sea-level, and forms almost the lowest dip in our plateau. It is like the bottom of 

 a vast platter, or the centre in the hollow of a mighty hand. Around this de- 

 pression there are on all sides uplands of various heights like gradations in the Asiatic 

 terrace terminating in the intermediate ranges, or in the outer circumvallation of 

 mountains already described. On the east of it there is the tract called Eastern 

 Gobi, chiefly desert, and Mongolia, averaging 4,000 feet above sea-level : on the 

 north the Altai uplands, exceeding 5,000 feet. On the west the Pamir rises 

 abruptly, exceeding 13,000 feet ; on the south Tibet, with eqiual abruptness, having 

 an aAerage altitude of 15,000 feet above sea-level, thus being the loftiest expanse in 

 the world ; and on the south-east the tract around the Kuku Nor Lake, 10,000 feet. 

 Further, there is a detached depression known as the Zungarian strait, extend- 

 ing to the northern confine of our plateau between the Thian Shan and the Altai 

 ranges. This strait, hardly exceeding 2,000 feet above sea-level, is as low as, 

 perhaps even lower than, any part of oar plateau, and is very near brealring its 

 continuity, which may be considered as being just saved b}' the comparatively 

 humble altitude above mentioned. The depression is geographically important as 

 forming the only broad pass between our plateau and the world without. It 

 runs from Mongolia, the most important tract within our plateau, to Siberia out- 

 side. Great value was, in early times, attached by the Chinese to it, as being the 

 only natural highway on a large scale between Northern and Central Asia. 



The e.xistence of this and the other depressions above described has led to 

 interesting speculations among geologists as to there having been, in primeval times, 

 within our plateau, at least one inland sea as large as the Mediterranean of Europe. 

 Be tliat as it may, there is no doubt that a process of desiccation has been going 

 on within our plateau during historic ages, whereby the climate is considerably 

 affected, and many signs or evidences show that this process is still in operation. 



On most of its sides our plateau is extraordinarily inaccessible, the passes being 

 steep in the extreme, and on the south ending in ridges 18,000 to 20,000 feet above 

 sea- level. Towards Siberia the Altai passes are easier, and on the north-east be- 

 tween Mongolia and China there are several passes that have witnessed the historic 

 outpourings of the Mongol hordes, and which are ominously remembered by the 

 Chinese as the openings through which their invaders rushed like the great river 

 in flood, or the landslip from the mountain side, or the avalanche sweeping along 

 the boulders and debris to the destruction of the valleys beneath. 



The great desert of Eastern Gobi occupies the eastern portion of our plateau. 

 With its accumulating forces of sand and powdered earth it has a tendency to 

 encroach, and is regarded by man with a vague awe. Its present extent is 

 enormous, being not less than half a million of square miles. Nor does it exist 

 alone within our plateau, for between the Tarim basin and the Kuen-lun spurs there 



