I was not content with merely closing the entrance, but getting some strong vines, I intertwined them round the walls and then got some large boughs, and placed them over the whole building. I trusted that thus no animal could possibly enter. I knew that sufficient air would be obtained through the roof. All that I could do was to pray, for his sake and my own, that I might return in safety to him. "Good-bye, Natty," I said, when I had finished the work. "Keep up your spirits, my boy. I hope soon to be back; but if I do not come as quickly as you expect, do not be alarmed. I may have to go some way for water." My wisest course perhaps was to have gone back to the last stream we had passed; but then I could not have returned the same night to our hut, and what would poor Natty have done all that time without me? I therefore determined to push on in an opposite direction, hoping that I might meet with a fountain or rivulet. On and on I went. The sun, as he rose in the sky, grew hotter and hotter. I had not a drop of water to cool my dry tongue. I had never before really known the feeling of want of water. I had been very thirsty; but now the whole inside of my mouth and throat seemed to consist of a dry horny substance, or as if I had swallowed some of the contents of a dust-bin. Still on and on I went. I hoped by continuing in a direct course that I should obtain water more speedily. A considerable portion of the day had passed away. The sun had attained its greatest heat, when I thought I saw in the distance a line of trees, which I felt sure indicated the presence of water. I pushed on more eagerly, but as I advanced they changed their outline, and suddenly disappeared. All I could see before me was a low line of grass and bushes, which had evidently been magnified by a mirage into the proportion of lofty trees. I went on, but continued to be deceived time after time in the same way. In every direction the mirage danced on the plain. I found that in reality the range of my vision was restricted to a very moderate distance. Suddenly a herd of animals appeared, lifted completely up in the air. They were deer of some species. I hoped by killing one that I might somewhat quench my raging thirst with its blood, but before I had got up to where I had seen them they had scampered off. At length I saw what I felt sure was a pool of water. Eagerly I hurried towards it. It was a long way off, I thought; but I was willing to go any distance for the wished-for fluid, hoping that my sufferings would find relief, and that I might return before nightfall to my young companion. I was confirmed in my opinion by catching sight of several gnus going in the same direction. "They are going there to drink," I thought; and I felt ready even to encounter lions or any other savage beasts for the sake of the water. The gnus did not perceive me, as they were to windward. There was, however, so little wind that I had