214 F. Kingdon Ward—The Land .of Deep Corrosions. 
the whole it appears to be so. But the gorges in which flow the 
’Nmai-hka, Salween, Mekong, and Chin-sha are not simple synclines 
deepened by erosion; they are more in the nature of rifts, gashes, or 
possibly faults produced by some other agency. 
If we cross all the valleys and mountain ranges, starting from the 
Brahmapootra, and travelling eastwards, keeping always in the same 
latitude, we shall find that as we pass from one valley to the next, 
we are gradually ascending, and also crossing successively higher 
mountain ranges between them, till the maximum average height is 
reached on the divide separating the Mekong from the Chin-sha for 
the short distance these rivers flow parallel to one another. The 
Mekong—Yangtze divide, however, is not the most snow-clad, for 
being protected from the monsoon by rain-screens to the west it 
receives only a fraction of the precipitation which falls on the 
western ranges, exposed to the full onslaught of the monsoon. Thus 
the entire region from the Brahmapootra to the Yangtze, in about 
latitude 28°, presents the appearance of a hugh bulk of rock, crystalline 
in the east, inclined from west to east, and trenched, riven, split 
asunder again and again from north to south. 
Now: how are we to account for the fact that the river beds from 
west to east, irrespective of volume and velocity and therefore of 
their erosive powers, namely, in order the Brahmapootra, Mali-hka, 
’Nmai-hka (western and eastern branches of the Irrawaddy re- 
spectively, the latter being the maz stream), Salween, Mekong, and 
Chin-sha (Yangtze), lie at successively higher and higher levels? 
The problem is complicated by the fact that the rivers are of different 
ages, the Irrawaddy evidently being the most recent, while the 
Chin-sha is probably the oldest. The regularity of the ascent is not 
due to a progressive decrease in the erosive power of the rivers, due 
either to.a decrease in grade, to a decreased volume of water, or to 
any difference in the composition of the rocks over which they flow. 
The Mekong is a bigger and swifter river than the ’Nmai-hka, but it 
flows:at a higher level by some 2,000 feet. The Salween has a bigger 
volume of water than the Mekong, but flows over 1,000 feet 
below it. We cannot ascribe the phenomenon to chance, and the 
only explanation seems to be that the country realty does represent 
an inclined block of strata; and unless it has itself been planed 
down and carved out in this way, which is what we are endeavouring 
to show that it has not, and that it never existed above water except 
as a series of parallel ridges and valleys, we are almost forced to the 
conclusion that it must have been pushed bodily up over an inclined 
plane of older rock which it now overlaps. This sorts well with the 
belief, founded on a consideration of glacial phenomena and floral 
distribution, that the ridges were pushed up one by one from the 
west, by a lateral movement of the Himalayan axis. If such bodily 
movement of the mass did take place, it is easy to account for the 
rifts in which the rivers now flow, by fracture. If the pressure 
which gave rise to the original underlying synclinal structure was 
sufficient also to force this huge mass bodily up an inclined plane of 
older strata, sloping gently down to the west, at less than a degree,* 
1 If the slope from the Chin-sha Valley to the Brahmapootra were uniform, 
it would be, in round numbers, about 1 in 3,000, or a slope of 20 seconds. 
=) 
