Wier Catan heat seats ee aie oe at a oie deme py Pg LS 8 
BSA er SE COI 
C. E. Dutton—Hawaiian Volcanoes. 221 
4 fragments of the frozen surface plunge downward, leaving the 
whole one glowing mass of lava. For a few minutes the spec- 
tacle is very grand, but it does not last long. The surface 
The period between break-ups is not regular, being as short as 
forty minutes and as long as two hours and a quarter. 
e explanation of the phenomenon is, I think, not difficult. 
When the lava first passes from the liquid to the solid condi- 
tion, while its temperature is still near the melting point, but 
below it, its density is less than that of the lava below. 
the crust thickens and the surface becomes cooler, its densit 
becomes greater than that of the lava below, and its position 
then becomes unstable. A slight disturbance produces a rup- 
ture, and the sinking of one fragment is quickly followed by 
that of the others. 
t has been the custom to speak of Kilauea as being situated 
upon the flanks of Mauna Loa and to regard it as a mere ap- 
pendage of that mountain. But it presents itself to me asa 
distinct voleano having no more connection with Mauna Loa 
than Mauna Kea has. Into the discussion of this I cannot now 
enter, 
From Kilauea I went to Mauna Loa. first objective 
point was the source of the last great eruption of 1880-81. 
It is reached with difficulty on account of the roughness of 
the clinker fields, or aa, as it is termed in the islands. The 
vents are situated from twelve to eighteen hundred feet below 
su 
ances presented at this point I shall describe at a future time. 
t may be sufficient to state here that a series of parallel fis- 
sures pointing from the summit toward the base of the 
mountain gave issue to the lavas. No cone was built, and 
there is no accumulation whatsoever of fragmental eruptive 
products. 
many eye witnesses of these eruptions recite observa- 
tions which strike me as most extraordinary, though I cannot 
for a moment question the general truthfulness of these ac- 
