78 DR. THOMSON's MISSION TO THIBET. 
to Le joined the Indus at Kalatze, more than forty miles below that 
town. The journey therefore occupied me more time than I had anti- 
cipated, but as I crossed numerous mountain ranges I had more op- 
portunity of seeing the country. I made four marches along the valley 
where it was open, and villages were plentiful; then turning to the 
right, traversed two high ridges, one upwards of 16,000 feet, and again 
descended to the Zanskar river, but only to cross it and strike into the 
mountains on the left bank. After crossing three ranges, the first 
16,500 feet high, I reached the Indus, and followed its course to Le. 
At Le I remained a week, and then started for this place, by a differ- 
ent pass from that by which I travelled last year. 
I must now try to give you some account of what I have seen 
since entering Thibet, and the comparative novelty of the country will 
I trust serve to excuse my dry and uninteresting narrative. I shall 
probably repeat a good deal of the contents of my last year’s letters, 
for which also I must beg you to excuse me. The whole course of the 
Indus, north of Himalaya, is through a mountainous country, without 
any extensive table-land. The valley of the river diminishes of course 
in elevation as the stream advances. to the sea, but the mountains 
throughout seem to have pretty much the same elevation, namely, from 
18,000 to 20,000 feet, afew peaks rising a little higher. The main 
valley and some of the larger lateral ones have occasionally a width of 
two or three miles, but: the latter are more frequently mere ravines, and 
often very narrow and precipitous ones. From between 12,000 and 
13,000 feet down to about 6,000 (my lowest point on the Indus) both 
the main valley and those of the tributaries are occupied by more or less 
of a lacustrine deposit which is often of enormous thickness. It occa- 
sionally but rarely contains fresh-water shells, and appears to me to 
indicate that at a former period a lake extended throughout the whole 
interval between the elevations just mentioned, or from considerably 
above Le to forty miles or so below Iskardo. Of this extensive tract 
of country only a very small portion is cultivated, the whole of the 
mountains, and by far the greater portion of the valleys being abso- 
-— desert. The mountains are almost universally tipped with snow, 
their lower parts, where not rocky and precipitous, .consist either 
a steep sloping shingle, or of undulating stony tracts. The climate 
is universally characterized by great dryness. The winters are severe ; 
