Chap. XXIY. EOCKS AFFECTED BY HEAT. 493 



startled on sitting down on them after dusk to find them 

 quite too hot for the flesh, protected by only thin trousers, 

 to bear. The thermometer placed on them rises to 137° in 

 the sun. These heated surfaces, cooling from without by 

 the evening air, contract more externally than within, and 

 the unyielding interior forces off the outer parts, to a 

 distance of one or two feet. Let any one in a rocky place 

 observe the fragments that have been thus shot off, and 

 he will find in the vicinity pieces from a few ounces 

 to one or two hundred pounds in weight, which exactly fit 

 the new surface of the original block ; and he may hear in 

 the evenings among the hills, where sound travels readily, 

 the ringing echo of the report, which the natives ascribe to 

 Mchesi or evil spirits, and the more enlightened to these 

 natural causes. 



It would have been no great feat to have scaled these 

 mountains without any path to guide us ; but we could not 

 afford to waste the time necessary for a prolonged ascent. 

 Our provisions were nearly expended, so we pushed onward 

 to the north, in hopes of finding what we needed there. 



We afterwards discovered that the poor people had good 

 reason for not leading strangers, of whom they knew nothing, 

 to the stores of corn which, after the invasion, they had been 

 fain to hide amongst the crags of the hills. 



When we came abreast of the peak Chirobve,'the people 

 would no longer give us guides. They were afraid of their 

 enemies, whose dwellings we now had on our east ; and, 

 proceeding without any one to lead us, or to introduce us 

 to the inhabitants, we were perplexed by all the paths 

 running zigzag across instead of along the valley. They 

 had been made by the villagers going from the 

 hamlets on the slopes to their gardens in the meadows 

 below. To add to our difficulties, the rivulets and 



