I took no notice of his protest, and driving before me the two yaks, I stepped into the most sacred of all the sacred provinces--"the ground of God," as they call it. We descended quickly on the eastern side of the pass, while the soldiers, aghast, remained watching us. They were a picturesque sight as they stood among the _obos_ against the sky-line, the sunlight shining on their jewelled swords and the gay red flags of their matchlocks. Above their heads strings of flying-prayers waved in the wind. Having watched us for a little while, they disappeared. A little rivulet, hardly six inches wide, descended among stones in the centre of the valley we were following, and was soon swollen by other rivulets from melting snows of the mountains on either side. This was one source[8] of the great Brahmaputra, one of the largest rivers in the world. I must confess that I felt somewhat proud to be the first white man who had ever reached these sources, and there was a certain childish delight in standing over this sacred stream, which, of such immense width lower down, could here be spanned by a man standing with legs slightly apart. We drank of its waters at the spot where it had its birth, and then, following a marked track to the south-east, we continued our descent on a gentle incline along a grassy valley. The change in the climate between the west and south-east sides of the Maium Pass was extraordinary. On the western side we had nothing but violent storms of hail, rain, and snow, the dampness in the air rendering the atmosphere cold even during the day. The soil was unusually marshy, and little fuel or grass could be found. The moment the pass was crossed we were in a mild, pleasant climate, with a lovely deep-blue sky over us. We found plenty of grass for our yaks and low shrubs for our fires. After all our sufferings and privations, we felt that we had indeed entered the land of God. I expected great trouble sooner or later, but I was not sorry I had disobeyed the soldiers' orders and had marched straight into the most forbidden province of the forbidden land. There is always satisfaction in doing what is forbidden. The Brahmaputra received three small snow-fed tributaries descending from the steep mountains on either side of us. Where the main stream turned sharply south, a fourth and important tributary, carrying a large volume of water, came down through a gorge from the north-north-east.