32 Expedition to the 



In this time the mercury fell to 42°, the thermometer hang- 

 ing against the side of a rock, which in all the early part of 

 the day, had been exposed to the direct rays of the sun. At 

 the encampment of the main body in the plains, a corres- 

 ponding thermometer stood, in the middle of the day, at 96", 

 and did not fall below 80", until a late hour in the evening. 



Great uniformity was observed in the character of the rock 

 about all the upper part of the mountain. It is a compact, 

 indestructible aggregate of quartz and feldspar, with a little 

 hornblend in very small particles. Its fracture is fine gran- 

 ular or even, and the mass exhibits a tendency to divide 

 when broken into long, somewhat splintery fragments. It is 

 of a yellowish-brown colour, which does not perceptibly 

 change by long exposure to the air. It is undoubtedly ow- 

 ing to the close texture and the impenetrable firmness of this 

 rock, that so few lichens are found upon it. For the same 

 reason it is little subject to disintegration by the action of 

 frost. It is not improbable that the splintery fragments which 

 occur in such quantities on all the higher parts of the Peak, 

 may owe their present form to the agency of lightning; no 

 other caiise seems adequate to the production of so great an 

 eflfect. 



Near the summit, some large detached crystals of feld- 

 spar, of a pea-green colour, were collected; also large frag- 

 ments of transparent, white and smoky quartz, and an aggre- 

 gate of opake white quartz, with crystals of hornblend. 



About five in the afternoon we began to descend, and a 

 little before sunset arrived at the commencement of the tim- 

 ber, but before we reached the small stream at the bottom of 

 the first descent, we perceived we had missed our way. It 

 was now become so dark, as to render an attempt to proceed 

 extremely hazardous, and as the only alternative, we kind- 

 led a fire, and laid ourselves down on the first spot of level 

 ground we could find. We had neither provisions nor blan- 

 kets; and our clothing was by no means suitable for passing 



