﻿628 DE. TEMPEST ANDERSON ON THE [Nov. I9IO, 



At the south-western end of the crater is also a tunnel larger 

 and higher than that by which the lava escapes on the north-east. 

 Its interior is incandescent, and its floor occupied by liquid lava. I 

 am not at all sure that any lava goes out or comes in through it. 1 

 The whole bottom of the crater is, in fact, in such a turmoil, the 

 lava boiling and surging up first in one place, then in another, that 

 it is impossible to say definitely where the exact point of entrance 

 is. On the whole, I am inclined to think that it is mainly towards 

 the south-western end, in front of the entrance to the south- 

 western tunnel. It is not unlikely that a fissure extends for the 

 whole or greater part of the length of the bottom of the crater, 

 and possibly for some unknown distance beyond each end of it. 



The surface of the cone is mostly composed of a series of flows 

 of basaltic lava, similar in type to that which forms the fields 

 around. A considerable number of bombs or ejected blocks of lava 

 of similar character are scattered over the surface ; but beyond this 

 the evidences of explosive action, at any rate in the later stages, are 

 very few. In the earlier stages the action appears to have been 

 more of the explosive type (PI. XLV, fig. 2). 



The lava-fields are extensive and irregular in shape, as may 

 be seen from the accompanying map (p. 622). They comprise a 

 considerable area round the cone, being most limited on its southern 

 and eastern sides, where their further extension was prevented by 

 the hills. They are somewhat more extensive towards the west and 

 north in the direction of Safune and Safotu, where they have filled 

 up the upper parts of several valleys. This part of the field shows 

 a few fumaroles, and apparently receives the lava which enters the 

 small north-western tunnel from the crater. The most extensive 

 area, however, is towards the north-east in the direction of the sea. 

 It is at first confined between hills, and becomes narrowed and 

 sinuous in consequence, and lower down spreads out into the 

 broad expanse near the coast. The molten lava which enters the 

 tunnel at the north-eastern end of the crater flows under this part 

 of the field. The surface is very rough and irregular, and presents 

 large areas both of scoriaccous or cindery lava (locally called ' aa '), 

 and slaggy, ropy, or corded lava (locally ' pahoehoe'). Of the latter 

 variety there are large areas as regular as anything in Iceland, 

 where the Odadhraun presents hundreds of square miles of such 

 beds ; or, again, like the less regular corded and festooned lavas on 

 Vesuvius before they were covered up by the recent eruption ; and 

 there are fields composed of blocks of the surface-crust of such 

 varieties broken up by subsequent movement, and forming some 

 of the most difficult ground to traverse which it is possible to 

 conceive (PL XLVIII, figs. 1 & 2). 



One of the chief characteristics of these fields has been the 

 great fluidity of the lavas at the time when they were poured out. 



1 I have seen caves and tunnels in Halemaumau, the 'working pit' of the 

 crater of Kilauea, where the wall was being dissolved and undermined by 

 convection currents of hot lava. They presented appearances quite comparable 

 with this and the small lateral tunnel above mentioned. 



