The Land of Deep Corrosions 265 
With the abrupt change of climate the people change 
too. Onthe Mekong north of Yang-tsa the same conditions 
are repeated, if possible with even greater intensity. Never 
have I seen cliffs so stark, so hideously bare, gorges so 
forbidding. The river thunders wildly down its deep 
gutter, draining the Roof of the World—‘an exaggerated 
mountain torrent,’ as the French priest Degardine aptly 
terms it. Yet here and there, as on the Salween, a 
mountain torrent dashing down has thrust out a small 
alluvial fan hanging far up above the river, where cultivation 
is possible. It is indeed a beautiful sight to see one of 
these oases in the spring, green with wheat and walnut 
trees, in the summer golden with the ripening corn, where 
are concealed the pretty Tibetan ‘manor’ houses scattered 
down the terraced slope, while all around the enclosing 
cliffs rise bare and drear. 
It is the same on the Yang-tze flowing behind its rocky 
barrier to the east, but here the little villages, in some 
places perched far up on the steep valley walls, in others 
nestling down close by the water, are more numerous, so 
much bigger is the Yang-tze. Man has wrestled rudely with 
the problems of life by the River of Golden Sand for untold 
centuries, the mere thought of which, carrying one back 
to the ages when the river was perhaps young, makes the 
head reel. 
Thus all three rivers flow through an arid region, the 
southern limit of which may be set down as 28° 10’, while 
northwards it extends into the unexplored regions of Tibet. 
But whereas the Mekong flows through arid gorges for 
a long distance south of this, and the Yang-tze valley has, 
I imagine, a rainfall comparable to that of England, the 
Salween alone exhibits the two extremes of climate separated 
by an absolutely sharp line, the position of which could be 
marked down within a mile either way ; and in this respect 
at least it is the most marvellous river of all. It is not 
difficult to account for the arid region, however, bearing in 
mind the arrangement of the mountains and the direction 
of the rain-bearing wind. 
If the Salween-Mekong divide so thoroughly exhausts 
the winds of their moisture that the next ridge over which 
they sweep presents in consequence such different scenic 
