576 DAY AND SHEPHERD WATER AND VOLCANIC ACTIVITY 



that fact, its presence must be expected on one day as much as on another 

 in which the same gas and lava conditions appeared to prevail. 



He was also able to discover no diminution in the liquidity of the lava, 

 either in the crater or in the great lava streams during those periods when 

 no cloud was seen, and therefore no causal connection between the pres- 

 ence of the gases and fluidity of the lava. 



Had it occurred to Green to try to remelt some of the solidified lava 

 after the gases had escaped, this last puzzling question would have been 

 clearer to him, for the crudest effort would at once have revealed the fact, 

 which since then has often been noted, that these lavas, when reheated to 

 the temperature prevailing in the lava lake before solidification, remain 

 quite rigid — the characteristic fluidity has departed with the escaping 



Bran's statement of his observations at Kilauea is more explicit. In 

 particular he offers six definite reasons for believing that steam is not 

 present either in the lava basin or in the cloud above it. They are these : 



( 1 ) The cloud arising from the crater does not evaporate in the sun as 

 do the clouds arising from neighboring cracks after a rain, but can be 

 seen floating majestically away often for 20 miles or more. 



(2) No rainbow or other optical phenomena can be detected in the 

 cloud arising from the crater, although rainbows are abundant enough in 

 the vicinity under appropriate conditions. 



(3) If the cloud were of steam emerging from white-hot lava, there 

 should be an interval of a few feet between the point of emergence and 

 the beginning of condensation (like the dark space immediately in front 

 of the spout of a steaming tea-kettle) in which the steam should be in- 

 visible. No such dark space could be seen. 



(4) As the cloud rises past the rim of the crater on the leeward side, 

 the walls about the crater, being comparatively cold, should be wet with 

 the condensed vapor, whereas in fact these walls remain quite dry. 



(5) A train of glass tubes was lowered over the rim of the crater for a 

 few yards on the side where the cloud was emerging, and through these 

 tubes (some 250 feet distant from the nearest liquid lava, it may be re- 

 marked) air and the vapors carried by it were pumped for several minutes, 

 but no trace of condensed moisture appeared on the inside walls of the 

 tubes. Examination with a hand lens revealed the fact that the tube walls 

 were quite thickly covered with crystallized salts, some of which were 

 stated to be hydrates or to be hygroscopic, but this was deemed to be due 

 to original moisture ( !) carried on the tube wall before the beginning of 

 the experiment. No analyses of the gases or of the solid salts are given. 



