Necessarily I had to content myself with taking my bearings by the sun, the position of which I got fairly accurately by constantly watching the shadow projected by my body on the ground. Of course, when it rained or snowed, I had to reckon my bearings by the observations of the previous day. We travelled first west, then successively west-north-west, north-west, west, and north-west, following the Brahmaputra along a course south of the outward journey, until we reached the boundary of the Yutzang (the Lhassa) province. The soldiers of our guard were severe with us. They ill-treated us in every possible way. Only one or two of the soldiers showed thoughtfulness, bringing us a little butter or _tsamba_ whenever they could do so unseen by their comrades. The guard was changed so frequently that we had no chance of making friends with the men. Each lot seemed worse than the last. A curious incident happened one day, causing a scare among the Tibetans. We had halted near a cliff. The soldiers were some twenty yards off. Having exhausted all other means to inspire these ruffians with respect, as a last resort I tried ventriloquism. I spoke, and pretended to receive answers to my words from the summit of the cliff. The Tibetans were terror-stricken. They asked me who was up there. I said it was some one I knew. "Is it a _Plenki_?" "Yes." Immediately they hustled us on our yaks while they mounted their ponies, and we left the place at a great speed. On reaching a spot, which from observations taken on my outward journey I reckoned to be in longitude 83 deg. 6' 30" east, and latitude 30 deg. 27' 30" north, I had a great piece of luck. It was at this point that the two principal sources of the Brahmaputra met and formed one river, one coming from the north-west, which I had already followed, the other coming from the west-north-west. The Tibetans, to my delight, selected the southern route, thus giving me an opportunity of visiting the second of the two principal sources of the great river. This second stream rose in a flat plain, having its first birth in a lakelet in approximate longitude 82 deg. 47' east and latitude 30 deg. 33' north. I gave the northern source my own name. I was glad to be the first white man to visit both sources of the Brahmaputra River. Dreary as this period of captivity was, yet it was instructive. As we went along, I got the soldiers to teach me several Tibetan songs, and from the less ill-natured men of our guard I picked up, by judicious questioning, a considerable amount of information. Over a more southerly and lower pass than the Maium Pass, by which, healthy, hopeful, and free, we had entered the province of Yutzang, we now left it, wounded, broken down, almost naked, and prisoners.