588 DAY AND SHEPHERD WATER AND VOLCANIC ACTIVITY 



were directly connected with the lake by channels of liquid lava just below 

 the surface crust. The collapse of the entire channel leading to the May 

 dome is shown in plate 24, figure 1. in which an arrow (f) has been 

 placed to indicate the position where the dome stood. The May dome 

 was under constant observation for several days and a considerable por- 

 tion of the night immediately previous to the collection, during which 

 time there was no cessation of the lava fountain spouting within the dome 

 nor of the flames of the burning gases as they escaped through its crack's. 

 Furthermore, as the larger bubbles rose and burst from the liquid lava 

 within the dome, the jar could be felt on the floor where the collectors 

 stood and the splash could be plainly seen through the cracks. 



Analyses of the Gases collected in May, 1912 



The following analyses were made of the fixed gases collected in glass 

 tubes on May 28, 1912, in the manner above described. The statement 

 is given in parts by volume. The tubes were numbered from 1 to 20 in 

 the order in which the gases entered from the volcano. All the tubes 

 contained condensed water (the first — plate 24, figure 2 — containing 

 nearly 100 cubic centimeters), of which analyses will be found on page 

 592. 



Table 2 



The Gases from Halemaumau (Kilauea), May, 1912 



Percentages by volume 



Tube Tube Tube Tube Tube 



1 2 8 10 17 



Co 2 23. S 58.0 62.3 59.2 73.9 



CO 5.6 3.9 3.5 4.6 4.0 



H 2 7.2 6.7 7.5 7.0 10.2 



N 2 63.3 29.8 13.8 29.2 11.8 



SO, none 1.5 12 . 8 none none 



Rare gases none none none none none 



Hydrocarbons none none none none none 



The Influence of the Iron collecting Tube 



In the 15 minutes during which pumping was continued the short 

 length of iron pipe which extended into the dome was partly destroyed 

 by the joint action of the sulphur and S0 2 . Owing to the high tempera- 

 ture and the splashing of the molten lava, neither glass nor porcelain 

 would have withstood the ordeal, and a tube of silica glass was, unfortu- 

 nately, not available ; so that iron appeared to be the best material at hand 



