628 
Dll. TEMPEST ANDERSON ON THE 
[Nov. 1910, 
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 tioor occupied hv 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 surfaee ; 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 thev 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 oindery lava (locally called 4 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 XLV III, 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 Ivilauea, 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. 
