As the camels, as yet unused to their new substitute for water, were still suffering from thirst, we trekked through the night as we neared the big pan, for I was now on ground I knew, and able to steer an accurate course. Crossing the pan in the dark, we found no rain had fallen there, and we off-saddled in the western dunes, anxious for the morning to get on again, for the camels were now in a bad plight, and had still a long day’s journey before them before they could drink. Usually they were hobbled with huge straps and chains before letting them loose to graze, but this night my friend said, “Let ’em loose to-night; they’re too tired to go far.” We slept like logs, and in the morning the camels had gone! We made tracks for the highest dune--no sign of them. Then we separated and made for two other dunes. Still no sign. At last we circled to cut the spoors, and found they led north. After an hour’s running and walking, and with the spoor still making north, we stopped for breath. I said, “They’re making for Witdraai!” He said, “Not they. They’re making for Arabia!” At last, when I had given up all hope of catching them south of the Equator, the spoor turned off at right-angles, and after a few more dunes, turned directly back towards the camping-place of last night, where we found them quietly feeding within a hundred yards of their saddles, just hidden from our sleeping-place by a small dune. A few hours from Aar Pan my good Samaritan dropped me, and turned towards his camp with the two camels, having done everything in his power to help me, and acting the man and the sportsman in every way. [Illustration: THE HUGE NESTS OF THE “SOCIAL BIRDS.” These birds, although only the size of sparrows, build in colonies, and the resultant nests are often so huge that the limbs break with their weight.]