F. A. Ferret — Lava Fountains of Kilauea. 143 



held that the action is purely hydrostatic — the forcing up from 

 below of a simple liquid — and even included in this hypothesis 

 the greater occasional fountains of the Manna Loa crater, over 

 4000 meters above sea level. Daly* attributes the phenomenon 

 to the rising of a mass of lava lighter than the rest by reason of 

 greater vesiculation, and which, he says, is " best explained, in 

 part, on the principle illustrated in the upspringing of a log of 

 light wood freed at the bottom of a lake. Through its momen- 

 tum the log may jump clear out of the lake." 



Fig. 4. 



Fig. 4. Telephoto night view. " Old Faithful." Subsidence phase. 



The present writer goes much farther than this in the direc- 

 tion of a purely gaseous hypothesis, the principal reasons for 

 which are advanced below. 



It is, first of all, necessary to realize that, in the active 

 portion of the lake, we have a material which is physically 

 very different from the ordinary conception of lava, and 

 this difference lies principally in its marvellous, its super- 

 lative, mobility. Now, that a heavy liquid should be mobile 

 need not cause surprise, as this may be due to its molecular 

 formation — mercury has weight yet it is known as quick- 

 silver. But something more than this is required to account 

 for the mobility of the active lake lava, which is of a different 

 sort to that of mercury, and this is to be found, I believe, 

 in its high gas content. The lava is so charged with gas 



* Reginald A. Daly, " The Nature of Volcanic Action ;" Proc. Amer. Acad. 

 Sci., vol. xlvii, No. 3, June, 1911. 



