portion of its length we had found the Bogtsang-tsangpo thus occupying at least three different latitudinal valleys; but its proper channel is in the middle one, up which we travelled; into the other two it only makes short deviations, though to do so it has to break through the ranges which separate the valleys one from the other. We ascertained that it breaks through to the south in order to avoid a pass in its own proper valley; and it is for a precisely similar reason that it bursts through the northern range back again, for at that point we had to cross over a second minor pass in the latitudinal valley.
At Camp XCIV the Bogtsang-tsangpo had to some extent altered its appearance. Its current was, it is true, still collected into a deep and very distinctly defined bed; but it was manifestly smaller than it had been lower down. Its breadth was not more than 5 or 6 In., and it is probable also that between Camp XCIII and XCIV it is joined by so many spring-fed rivulets that it perceptibly increases; indeed in that same stretch it appears to receive some actual tributary, for while its water at the former camp was rather muddy, here at Camp XCIV, in the district called Devusang, it was as clear as crystal, so clear that when we stood on the steep banks we were able to see the fish swimming past in shoals. The grass was fairly good; where the banks are held together by grass and roots they overhang in places. The country immediately south of the river is marshy, and appears sometimes to be under water; the ground consists of slippery grey clay, dotted over with gnarled scrub.
On 3rd October we travelled for the last time beside the Bogtsang-tsangpo, fording the river not far from our camp, at a point where it is divided into two
branches. Our direction was towards the west-north-west. By this the latitudinal valley had assumed a more irregular form, its attendant mountain-ranges breaking
Hedin, Tourney in Central Asia. IV. 16
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