The valley enclosed between these two parallel ranges is the most thickly populated valley in Tibet. Grass is abundant, and fuel easily obtainable, and therefore thousands of yaks, sheep, and goats can be seen grazing near the many Tibetan camps along the Brahmaputra and its principal tributaries. The trade route taken by the caravans from Ladak to Lhassa follows this valley; and, as I came to Tibet to see and study the Tibetans, I thought that, although I might run greater risks, I could in no part of the country accomplish my object better than by going along this thickly populated track. [24] I passed the other source on the return journey. CHAPTER LXI Expecting trouble--Along the Brahmaputra--A thunderstorm--A dilemma--A dangerous river--Swamped--Saved--Night disturbers--A new friend. WE slept very little, as we expected the soldiers to attack us during the night to try and stop our progress, but all was quiet and nothing happened; our yaks, however, managed to get loose, and we had some difficulty in recovering them in the morning, for they had swum across the stream, and had gone about a mile from camp on the other side. The night had been very cold, the thermometer dropping as low as 321/2 deg.. We did not pitch our little tent, in case of emergencies, and we were tired and cold after the long march of the previous day. There was a South-westerly breeze blowing and I found it hard to have to cross the river, chase the yaks and bring them back to camp. Then, exhausted as we were, we had in addition to go through the daily routine of loading them. We followed the right bank of the stream to bearings 170 deg. (m.), then to 142 deg. 30' (b.m.), where it wound in and out between barren hills, subsequently flowing through a grassy valley three-quarters of a mile wide and a mile and a half long. It then went through a narrow passage to 17 deg. 30' (b.m.) and turned to 103 deg. and farther to 142 deg. through an undulating grassy valley two miles wide, in crossing which we were caught in a terrific thunderstorm, with hail and rain. This was indeed an annoying experience, for we were now before a very large tributary of the Brahmaputra, and the stream was so swollen, rapid and deep that I was much puzzled as to how to take my men across: they could not swim, and the water was so cold that a dip in it would give any one a severe shock. However, there was no time to be lost, for the river was visibly rising, and as the storm was getting worse, difficulties would only increase every moment. We took off every stitch of clothing and fastened our garments, with our rifles, &c., on the pack-saddles of the yaks, which we sent into the water. They are good swimmers, and though the current carried them over a hundred yards down stream, we saw them with satisfaction scramble out of the water on to the opposite bank. Notwithstanding the faith that Chanden Sing and Mansing had in my