200 ROCK STREAMS. [chap. ix. 



the former owes its origin to the sandstone having- been 

 heated to such a degree that it became viscid, and upon 

 cooling crystallized. While in the soft state it must have 

 been pushed up through the overlying beds. 



In many parts of the island the bottoms of the valleys are 

 covered in an extraordinary manner by myriads of great 

 loose angular fragments of the quartz rock, forming 

 ''streams of stones." These have been mentioned with 

 surprise by every voyager since the time of Pernety. The 

 blocks are not waterworn, their angles being only a little 

 blunted ; they vary in size from one or two feet in diameter 

 to ten, or even more than twenty times as much. They are 

 not thrown together into irregular piles, but are spread out 

 into level sheets or great streams. It is not possible to 

 ascertain their thickness, but the water of small streamlets 

 can be heard trickling through the stones many feet below 

 the surface. The actual depth is probably great, because 

 the crevices between the lower fragments must long ago 

 have been filled up with sand. The width of these sheets 

 of stones varies from a few hundred feet to a mile ; but the 

 peaty soil daily encroaches on the borders, and even forms 

 islets wherever a few fragments happen to lie close together. 

 In a valley south of Berkeley Sound, which some of our 

 party called the ** great valley of fragments," it was necessary 

 to cross an uninterrupted band half a mile wide, by jumping 

 from one pointed stone to another. So large were the 

 fragments, that being overtaken by a shower of rain, I 

 readily found shelter beneath one of them. 



Their little inclination is the most remarkable circumstance 

 in these ''streams of stones." On the hill-sides I have seen 

 them sloping at an angle of ten degrees with the horizon ; 

 but in some of the level, broad-bottomed valleys, the Inclina- 

 tion is only just sufficient to be clearly perceived. On so 

 rugged a surface there was no means of measuring the 

 angle ; but to give a common illustration, I may say that 

 the slope would not have checked the speed of an English 

 mail-coach. In some places, a continuous stream of these 

 fragments followed up the course of a valley, and even 

 extended to the very crest of the hill. On these crests huge 

 masses, exceeding in dimensions any small building, seemed 

 to stand arrested in their headlong course ; there, also, the 

 curved strata of the archways lay piled on each other, like 

 the ruins of some vast and ancient cathedral. In endeavour- 

 ing to describe these scenes of violence one is tempted to 



