The first hour’s march was fairly easy. Level stretches of sand covered with patches of mineral salts, and dotted with stunted thorn trees, offered no great impediment to our progress. Several rhinoceros were browsing about, one brute being right in our path. We cautiously approached and shouted at him, but he did not seem disposed to move. On approaching nearer we saw that he was wounded, a great hole in his ribs showing that he had been fighting his brother rhinoceros, and had, apparently, considerably the worst of the argument. Rhinoceros are inveterate fighters amongst themselves; and of all the animals shot during the expedition there was not one who did not show healed or partially healed wounds somewhere in the region of the ribs. As this particular beast would not move, I started forward with the intention of shooting him, but he suddenly awoke to the exigencies of the situation, and quietly trotted out of harm’s way. As we proceeded, smooth patches of black lava showed themselves above the surface of the sand, and quartzose rocks occurred here and there. Half a mile further on rose a plateau about 25 feet high, apparently composed of some black substance. It lay right in our path, and we pushed forward towards it in order to more closely examine it. When we arrived at the foot, we found, to our dismay, that it was composed of blocks of black vesicular lava, varying in size from a football to an ordinary trunk. It stretched in either direction, left and right, as far as the eye could see, and there was no alternative but to attempt to cross over the top, which we were very loth to do, although we consoled ourselves with the thought that it would only be for a few hundred yards. We therefore scrambled to the summit, and only then got a faint idea of what was before us. The whole country round was covered with loose blocks of lava to a depth of 30 to 50 feet. The surface was not even fairly level, but was irregularly disposed in heaps, forming little hills and valleys of loose and often insecurely poised stones. There was a great and ever-present risk of a careless movement bringing two or three tons of stuff rolling down, and obliterating the unfortunate individual who had disturbed the _status quo_. The hard slag-like blocks were perforated by innumerable holes caused by air-bubbles when the lava was fluid, giving them the structure and appearance of a dark brown, or black, petrified sponge, the ragged edges of which soon reduced our boots to ribbons. The men who were wearing sandals suffered severely, as did the animals. It was, of course, impossible to ride, the mules having painfully hard work even to get along alone.