But that one lay beneath our feet we were certain, since, although we marched along the edge of precipices, our path, however steep, was always flat; moreover, the rock upon one side of it had often been scarped by the hand of man.

Of this there could be no doubt, for as the snow did not cling here, we saw the tool marks upon its bare surface.
Also we came to several places where galleries had been built out from the mountain side, by means of beams let into it, as is still a common practice in Thibet.

These beams of course had long since rotted away, leaving a gulf between us and the continuation of the path.

When we met with such gaps we were forced to go back and make a detour round or over some mountain; but although much delayed thereby, as it happened, we always managed to regain the road, if not without difficulty and danger.
What tried us more--for here our skill and experience as mountaineers could not help us--was the cold at night, obliged as we were to camp in the severe frost at a great altitude, and to endure through the long hours of darkness penetrating and icy winds, which soughed ceaselessly down the pass.
At length on the tenth day we reached the end of the defile, and as night was falling, camped there in the most bitter cold.

Those were miserable hours, for now we had no fuel with which to boil water, and must satisfy our thirst by eating frozen snow, while our eyes smarted so sorely that we could not sleep, and notwithstanding all our wraps and the warmth that we gathered from the yak in the little tent, the cold caused our teeth to chatter like castanets.
The dawn came, and, after it, the sunrise.