20 TRANSACTIONS OF THE [Sess. lxxx 



the appearance of these valleys under ice, and with the 

 vision fresh in my mind, journeyed across to the Mekong- 

 Salween divide in order to examine more closely the largest 

 of its glaciers (flowing to the Mekong) which are so well 

 seen from the former range. These glaciers, it may be re- 

 marked, are extremely difficult of access, as they flow in 

 narrow sheer-sided gorges and over steep beds which at 

 one point are generally precipitous or nearly so, so that the 

 crlacier comes staggering down in a tumult of fantastic 

 pillars. This comparison convinced me that the rarity of 

 lateral moraines and absence of perched blocks followed 

 naturally in the case of these short ^ steep glaciers, enclosed 

 in o-orges, and that did these glaciers on the Mekong-Salween 

 divide disappear, neither perched blocks nor lateral moraines 

 would be left to prove their previous existence, nor would 

 easily recognisable terminal moraines be met with. One 

 important result, however, for which I was not prepared, 

 was the discovery that these glaciers too have retreated 

 .some distance, and are evidently still retreating, and, as this 

 is an important point, it will be as well to go into it in 

 some detail. Examining the foot of tlie largest glacier — 

 the only part of it accessible to any but a party of expert 

 climbers — I found it to terminate in several tongues, sloping 

 gradually to the stream-ljed. Down in the valley below 

 were travel terraces cut out by the stream, and looking up- 

 stream, the left bank (facing south) was seen to be a line 

 of sheer clifls which soon reached a height of several hundred 

 feet; hanging valleys opened into the main valley on either 

 side, all the streams from the northern ridge cascading on 

 to the glacier. From a little above the glacier foot, and 

 extending for half a mile beyond it down the valley, was 

 a high and steep bank of earth almost bare of plants for 

 half its height, but covered at the summit with forest : this 

 was in fact a very perfect lateral moraine, in which I found 

 scratched stones. Further, the moraine showed indications 

 of a step structure, suggesting periodic fluctuations in the 

 retreat of the ice. The lowest part was quite bare, then 

 appeared a few small plants struggling to establish them- 

 selves, while above the highest step (marked A in the 



^ The longest glacier was not more than five mile.s in length, prob- 

 aVjly less. 



