KILAUEA, HAWAIL 205 
tain in the few hours at the crater; we can only mention here the 
common statement, derived from experiments on the surface lavas of 
Vesuvius, that it is between the point of fusion of silver and copper, 
or about 1900° F. ‘The scoria of Kilauea melts before a blowpipe 
with the same ease as silver. The compact lavas have nearly the 
difficult fusibility of feldspar, and would require a heat for fusion far 
beyond 1900°._ A complete series of experiments on the heat of fluid 
lavas is much needed, and nowhere could they be made with greater 
facility than at Kilauea.* 
The unusual liquidity of the Kilauea lavas, implies the existence 
either of greater heat, or of a more fusible material. From the ana- 
lysis of a feldspar from Maui, and other examinations to be detailed, 
we have found that the feldspathic ingredient of the lavas contains, 
like anorthite, twenty per cent. less of silica than albite or ordinary 
feldspar. It fuses with difficulty before the blowpipe on thin edges, 
and therefore does not help us in our explanations. 
IX. Kilauea not a Solfatara—Von Buch has spoken of Kilauea as 
a solfatara. The term, as is evident from the descriptions given, is 
wholly misapplied. A solfatara is an area with steaming fissures, and 
escaping sulphur vapours, and without proper lava ejections; while 
Kilauea is a vast crater, with extensive lava ejections and no sulphur 
except that of the sulphur banks, beyond what necessarily accompa- 
nies, as at Vesuvius, violent volcanic action. It is true, the lavas 
of the crater, though they flow, it may be, three miles within the pit, 
never rise over its sides. But this is simply because the walls are 
not strong enough to sustain the requisite pressure. We may here- 
* Dr. Judd and Rev. T. Coan kindly consented, at the author’s request, to make some 
attempts to determine the temperature of the lavas of Kilauea by means of the fusion of 
certain metals. The instrument was a long square iron rod, in one end of which there 
were cavities for receiving the metals, which were covered by plates of iron that were 
held in place by a ring. A long handle of wood was fitted to the rod, so that in all it 
was twenty-two feet long. After some unsuccessful attempts to use it, a convenient time 
finally offered, and at imminent hazard the rod was inserted. But they failed of their 
object in a manner they little expected. It was left inserted for twenty minutes, and on 
returning to it, with a feeling of certain success, the lavas were found to have hardened 
over it where it lay on the edge of the pool, These gentlemen are of the opinion that 
they would have been successful had they kept the rod in motion. By using different 
alloys, of which the fusing temperature is known, the heat of the surface lavas might in 
this way be obtained with much accuracy. 
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