214: Jaggar — Volcanologic Investigations at Kilauea. 



Summary of Temperatures. 



By summarizing the results of these two groups of tests it 

 appears that the lake magma immediately below the surface 

 glow lines has a temperature range from 750° to 850° C; that 

 the lava in the fountaining grottoes has a temperature range 

 from 1100° to 1200° C; and that the oxidizing gases in the 

 blow^iug cones have temperatures ranging from 1250° C. within 

 the cones to 1350° C. or higher at the flaming orifices. 



Keverting now to the queries asked at the beginniug of this 

 section, it would appear that the temperature range measured 

 by Ferret, Day and Shepherd, namely 1000° to 1185° C, is 

 correct for the fountaining lava, but that tlie temperature of 

 ordinary lava beneath the crusts is not the same as that of the 

 fountains, but much lower. As the melting point of the basalt 



Fig. 21. 



Fig. 21. Jan. 7, 1917. Looking W. at blowing cone biiilt above arclied 

 lava flows roofing N.W. conduit pond, A similar roof was seen to fall in 

 suddenly a few weeks before. The middle figure is looking into flaming ori- 

 fice, 3 ft. (1 m.) across, in summit of cone and 12 ft. (3 m.) below could be 

 seen the fountaining lava. This cone, built higher by spatter, with lateral 

 window instead of summit orifice, was the scene of temperature measure- 

 ment which fused steel pipe Jan. 26, 1917. Photo Jaggar. 



is near 1100° C, the lake melt would rank as superfused, or 

 fluent and unsolidified below its fusing point, if it could be 

 treated as a pure melt. Furthermore it becomes plain, on the 

 other hand, that the hot gases rising through this same lava 

 become vastly hotter, when confined in a spatter cupola above 

 the lava, and hotter still when liberated for complete combus- 

 tion in air. The conclusion seems Justified that the heating 

 effect is due to union with oxygen, and that tliis union begins 

 below the fountains, increases within the blowing cones, and 

 culminates in the visible flames. 



