towards the railway. Another half-hour took us to the springing of this, and we breasted the low edge of the plateau which was the watershed between Hejaz and Sirhan. Ten yards more, and we were beyond the Red Sea slope of Arabia, fairly embarked upon the mystery of its central drainage.
Seemingly it was a plain, with an illimitable view downhill to the east, where one gentle level after another slowly modulated into a distance only to be called distance because it was a softer blue, and more hazy. The rising sun flooded this falling plain with a perfect level of light, throwing up long shadows of almost imperceptible ridges, and the whole life and play of a complicated ground-system—but a transient one; for, as we looked at it, the shadows drew in towards the dawn, quivered a last moment behind their mother-banks, and went out as though at a common signal. Full morning had begun: the river of sunlight, sickeningly in the full-face of us moving creatures, poured impartially on every stone of the desert over which we had to go.
Auda struck out northeastward, aiming for a little saddle which joined the low ridge of Ugula to a lofty hill on the divide, to our left or north about three miles away. We crossed the saddle after four miles, and found beneath our feet little shallow runnels of watercourses in the ground. Auda pointed to them, saying that they ran to Nebk in Sirhan, and that we would follow their swelling bed northward and eastward to the Howeitat in their summer camp.
A little later we were marching over a low ridge of slivers of sandstone with the nature of slate, sometimes quite small, but other times great slabs ten feet each way and, perhaps, four inches thick. Auda ranged up beside my camel, and pointing with his riding-stick told me to write down on my map the names and nature of the land. The valleys on our left were the Seyal Abu Arad, rising in Selhub, and fed by many successors from the great divide, as it prolonged itself northward to Jebel