198 



K I L A U E A. 



hours. The distance being a httle over ten miles, the velocity must 

 have been about four hundred feet an hour. 



We proceeded dovs^n the lava stream until it expanded to a width 

 of three or four miles. There are many fissures along the whole line, 

 as will be perceived by the dai'k places on the map. I feel confi- 

 dent that from each of these an ejection had taken place, and that the 

 lava had in some cases flowed in a contrary direction to the general 

 course of the stream ; for being traced in such cases, it was seen to 

 have proceeded from a fissure that had occurred on rising ground. 

 Wherever the ground was steep, it was there perceived that tunnels 

 or hollowed places occurred, in consequence of the molten lava having 

 flowed from beneath the crust formed by cooling. The upper part 

 of the stream was composed of the description of lava called pahoihoi; 

 the lower portion was much broken, though not of that description 

 called clinkers, and seemed as though it had been crowded together 

 and broken up like ice in the breaking up of the frost in our rivers, 

 slab overlaying slab, and many of them ground to pieces by the great 

 pressure from behind. 



About six miles from the sea, it appeared as though there had been 

 , 11 /,„>.,,/ ^--1. ,-., , a simultaneous outbreak over a 

 .i\i,\iWi — ^A^ > ,1 , large area. The stream was suffi- 



ciently fluid at all places to seek 

 the lowest level, and an idea of the 

 flowing may be formed from the 

 annexed diagram, which I sketched 

 from the top of a cone. 



Near the centre of this flow was 

 a mound that had been covered 

 with trees. These were all left 

 standing, but had not a leaf upon 

 them, which increased the deso- 

 late appearance of the scene before 

 us. In our walk we occasionally met a "blowing cone," with quan- 

 tities of salts, sulphur, and hot sulphureous gases still issuing from it. 

 After having satisfied ourselves with this part, we ascended an old 

 crater-hill, and crossing over it, came to an old lava plain, of the kind 

 called pahoihoi : this appeared quite solid, and its surface was un- 

 broken ; there were no holes like those I have described on the recent 

 flow ; but in place of them there were a large number of raised 





LAVA FLOW. 



