We waded across the rapid Luia, which took us up to the waist, and was about forty yards wide.  The water was discoloured at the time, and we were not without apprehension that a crocodile might chance to fancy a white man for dinner.  Next day one of the men crawled over the black rocks to within ten yards of a sleeping hippopotamus, and shot him through the brain.  The weather being warm, the body floated in a few hours, and some of us had our first trial of hippopotamus flesh.  It is a cross-grained meat, something between pork and beef,—­pretty good food when one is hungry and can get nothing better.  When we reached the foot of the mountain named Chipereziwa, whose perpendicular rocky sides are clothed with many-coloured lichens, our Portuguese companion informed us there were no more obstructions to navigation, the river being all smooth above; he had hunted there and knew it well.  Supposing that the object of our trip was accomplished we turned back; but two natives, who came to our camp at night, assured us that a cataract, called Morumbwa, did still exist in front.  Drs. Livingstone and Kirk then decided to go forward with three Makololo and settle the question for themselves.  It was as tough a bit of travel as they ever had in Africa, and after some painful marching the Badema guides refused to go further; “the Banyai,” they said, “would be angry if they showed white men the country; and there was besides no practicable approach to the spot, neither elephant, nor hippopotamus, nor even a crocodile could reach the cataract.”  The slopes of the mountains on each side of the river, now not 300 yards wide, and without the flattish flood-channel and groove, were more than 3000 feet from the sky-line down, and were covered either with dense thornbush or huge black boulders; this deep trough-like shape caused the sun’s rays to converge as into a focus, making the surface so hot that the soles of the feet of the Makololo became blistered.  Around, and up and down, the party clambered among these heated blocks, at a pace not exceeding a mile an hour; the strain upon the muscles in jumping from crag to boulder, and wriggling round projections, took an enormous deal out of them, and they were often glad to cower in the shadow formed by one rock overhanging and resting on another; the shelter induced the peculiarly strong and overpowering inclination to sleep, which too much sun sometimes causes.  This sleep is curative of what may be incipient sunstroke:  in its first gentle touches, it caused the dream to flit over the boiling brain, that they had become lunatics and had been sworn in as members of the Alpine club; and then it became so heavy that it made them feel as if a portion of existence had been cut out from their lives.  The sun is excessively hot, and feels sharp in Africa; but, probably from the greater dryness of the atmosphere, we never heard of a single case of sunstroke, so common in India.  The Makololo told Dr. Livingstone they