4-2 CURATIVE SLEEP. CHAP. II. 



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 " always thought 

 he had a heart, but now they believed he had none," and 

 tried to persuade Dr. Kirk to return, on the ground that 

 it must be evident that, in attempting to go where no 

 living foot could tread, his leader had given unmistakeable 

 signs of having gone mad. All their efforts of persuasion, 

 however, were lost upon Dr. Kirk, as he had not yet 

 learned their language, and his leader, knowing his com- 

 panion to be equally anxious with himself to solve the 

 problem of the navigableness of Kebrabasa, was not at 

 pains to enlighten him. At one part a bare mountain 

 spur barred the way, and had to be surmounted by a 



