14 
THROUGH ASIA 
It would lead me too far were I to endeavour to 
render an account of the great problems that still await 
solution in the interior of Asia. The discovery of new 
chains of mountains, lakes, and rivers, of the traces of 
an ancient civilization, of antiquities which might possibly 
throw light on the great migrations of the races through 
Asia, the identification of old disused caravan roads, and 
finally the mapping of an entirely unknown region— all 
this possesses an irresistible attraction for the explorer ; 
but I can only touch upon one or two questions of 
peculiar interest. 
In the Asiatic highlands the geologist has unique 
opportunities of studying phenomena of the greatest 
possible interest, interesting not only on account of the 
processes of evolution which the mountain chains are 
actually undergoing there, but also for the reason that 
those mountain chains themselves are so little known. 
1 he tableland of Tibet rises like an enormous platform 
up to a mean height of thirteen thousand feet above the 
lowlands of Hindustan on the one side, and the desert of 
the Tarim basin on the other, the latter being one of the 
lowest depressions in the interior of any continent. Lake 
Lop-nor has an absolute altitude of not more than two 
thousand five hundred feet, and at Luktchin, south of 
Turfan, a depression has been found which actually lies 
a considerable distance below the level of the sea. On 
the side next the Tarim basin the Tibetan highlands 
are bounded by the Himalayas and the Kwen-lun, whose 
western extremities meet in the Pamirs and the regions 
south of it. While the older geographers and discoverers 
bestowed their attention upon little else save the topo- 
graphical appearance, or at most the surface elevations, 
of a country, modern geographical discovery claims from 
its surveyors reliable knowledge of the original causes 
of the present condition of the surface of the earth, and 
the genetic connection, origin, ag'e, and relation of the 
mountain chains to each other. There are important 
questions still to be solved in High Asia on these points, 
and a long period of time must necessarily elapse before 
