We made the long stage he foretold, and several longer after that. Hour upon hour, hour upon hour we rode up precipitous gullies and down seemingly impossible ravines, but always drew higher in the long run. The mere exertion of sitting our ponies was tremendous. I soon came to realise that never before, in a life that would be reckoned abnormally strenuous, had I really known what fatigue meant, and Poyning was worse off than I; but weariness never seemed to show itself on Philipson. At the first sign of flagging anywhere, he was to hand, helping or exhorting or bullying as the case appeared to him to demand, and getting us on the move again when you would have said flesh and blood could endure no more. His genius for organisation was no whit inferior to his energy, and his sense of country more astonishing than either. Time and again, when we had come to a sheer blind alley in the mountains and were at the end of our strength, Philipson divined a way out, found the necessary pass himself by searching on foot, and brought us safe over. The distances we travelled in a day were incredible. On one occasion we must have covered forty-five miles between sunrise and sundown, and that over some of the roughest and steepest country we had yet struck. Before the end of this stage Poyning was in a collapse, so weary that he could no longer keep his saddle; whereupon Philipson dismounted and walked beside him, holding the boy up, and for the last mile more than half carrying him in his arms. Yet I noticed it was Saunders Philipson who did most of the work in camp that night--the bearers themselves were dead beat--and that Philipson was first up in the morning, field glass in hand, scouring the mountainside for the easiest route. I couldn't help reflecting what a magnificent leader in war this man would have made. Good troops would have followed him to the very ends of the earth. I soon saw, too, the wisdom of his policy of taking mountain ranges at a run, for here we were, with the summer still before us, and the first great barrier range behind. The country began to descend, the going was easier and faster, and after a few days' march down a long slant we came within view of our first big landmark. I heard the bearers raise a shout and saw them throw out their arms, pointing. There, still far ahead, was a curious bluey shimmer on the rough yellow face of the earth. Philipson was scanning this through the glasses. 'What do you make of it, Mirlees?' he cried. 'It ought to be the head waters of the Yellow River,' I replied. 'Right. Or rather, the upper waters. The actual sources are about seven days farther on. When we reach them I can promise you a breather of three whole days.'