300 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1913. 



here, the adiabatic cooling on the one hand and the heat of reaction 

 between the gases on the other, for we do not yet know what all the 

 reactions are in such a complicated chemical system, nor do we pos- 

 sess any knowledge of the height of the lava column through which 

 the gases are free to react. In fact, if the tube which feeds the vol- 

 cano from below be supposed to contain both ascending and descend- 

 ing columns of liquid lava of widely variable temperature (Daly) 

 in which the circulation is primarily controlled by the (relatively 

 very large) differences of specific gravity, then it is indeed question- 

 able whether the common equations for adiabatic expansion find ap- 

 plication here at all. In any event, if we may assume such reactions 

 to be going on between the gases as : 



H. -f CO, = CO + H.O + 10,000 calories (Haber) 

 or 



CO -f i O. = COo + 68,000 calories (Haber) 



or the reaction between gas and lava : 



3FeO + H,0 = FeoO^ + Ho + 15,400 calories (Chamberlin) 



then the effect of adiabatic cooling is certainly of negligible magni- 

 tude in comparison with these. This is reasoning far beyond the 

 data now in hand, but it serves to shoAv that there is no cooling 

 effect of comparable magnitude with the heating effect of the reac- 

 tions going on within the active lava. 



If the reactions quoted above afford a proper measure of the order 

 of magnitude of the heat quantity thus released by chemical reaction 

 within the tube and surface basin of the volcano, we have here hap- 

 pened on an enormous store of volcanic energy which reaches its 

 maximum temperature at the surface itself. It is by no means cer- 

 tain at the moment that this discovery throws any new light on 

 conditions far below the surface, except perhaps to relieve us of 

 the necessity of postulating extreme temperatures for the iava 

 chambers below, which on other grounds must be considered highly 

 improbable.^ 



1 Whether these gas reactions may serve as a source of heat through which to point 

 the resemblance between volcanic phenomena and geyser action (Daly) must be assigned 

 rather to the realm of geologic speculation. At all events, the superficial phenomena at 

 Kilauea would seem to find a serviceable explanation without requiring any of the ejecta 

 except the gases to be of deep-seated origin. Indeed, the outbrealt in May, 1912, of a 

 lava stream from the talus immediately adjacent to the lava lal^e and some 40 feet above 

 its level (pi. 10) would seem to necessitate differences of pressure, and therefore 

 separate lava chambers, but short distances below the surface, in much the same ther- 

 modynamic relations as those supposed to exist between neighboring geysers of different 

 height and character. Hot gases from a common source percolating through chambers, 

 such as appear to honeycomb the Island of Hawaii, and reacting exothermally through- 

 out their journey as actively as a Bunsen burner, would appear to offer suflBcient amount 

 and variety of power to accomplish all the visible activity now seen there. 



