482 HARRY 0. WOOD 



.1 

 Kona, two of which were relatively small, though not to be mis- 

 taken for tongues. Of all these greater streams the Honomalino 

 branch was longest (see the map, Fig. 1). 



At its upper end the area of the new flow is narrow, varying in 

 width up to a third of a mile, and elongate parallel to the rift; its 

 margins here are irregular and lobate on a small scale. 



THE SOLFATARA-SPATTER-CONE SEGMENT 



For a mile above the head of outflow the open-fissure system 

 continues, at first in a direction about N. 3 W. mag., but in its 

 last third it curves gently eastward, so that the direction from the 

 foot of the flow-source segment to the head of this upper segment 

 is N. 2 W. mag. It is marked by an almost continuous line of fresh 

 solfataric action along which, in numerous protected niches, very 

 delicate, feathery, sulphur crystals were subliming in considerable 

 quantity, apparently in unusually pure aggregates (see the photo- 

 graphs, Plate VI, b, c). This action, and also all conspicuous 

 Assuring, ended in the flanks of an old red cinder cone, whose 

 summit is about 7,480 feet above sea-level and its base 7,375=*= , 

 which stood directly in the course of the major rift belt not far 

 from its western margin. 



Also there were observed along this segment three new spatter 

 cones, the largest 30 to 40 feet in height, wholly isolated from the 

 area of continuous flow; and several small spatter mouths, one of 

 which was situated very near the upper end of the segment at an 

 altitude of 7,370 feet above sea-level. 



Near their head the new flows are thin pahoehoe, either in 

 smooth sheets traversed by rift cracks of later origin, or, more 

 commonly, broken and torn crusts of pahoehoe transported and 

 piled into an irregular and confused surface (see the photographs, 

 Plate VI, d, and Fig. 4). Near the edges of flow, and the 

 edges of festooned flow channels, rough, a-a-like textures are seen 

 in all intermediate phases between "pulled" pahoehoe and 

 cindery a-a. Down their courses the flows become thicker and 

 their surfaces more irregular and fragmented, passing finally, 

 within a mile or two, through slaggy phases, into unmistakable 



