282 F. A. Ferret — Floating Islands of Halemaumau. 



20tli there were formed upon the surface the two islets shown in 

 the telephoto view (tig. 6). It was suspected that their forma- 

 tion was due to the chilling effect of the original island, 

 refloated to the surface but not emergent, and this was subse- 

 quently proved by a number of observations. It is highly 

 probable, therefore, that the many instances, in the past, of 

 the formation of new islets shortly after the disappearance of 

 an island has been due, as in the present case, to the reflota- 

 tion of the original mass. 



In the detail view, tig. 6, the flow of the surface lava, from 



Fig. 6. 





. ; ■ 



■'"'■'--. - ' - 





• 





Fig. 6. Twin Islands, formed by chilling effect of the sunken mass. 



right to left, is well shown, giving to the two islets the appear- 

 ance of buoys anchored in a tideway. 



The islets were repeatedly overwhelmed by upward oscilla- 

 tions of the surface lava and the writer, although not present 

 at the time, believes that the mass of the island must have 

 suffered fusion during the phase of abnormal activity which 

 occurred towards the end of the year. This would give to the 

 island as such, in the emergent state, an existence of about 

 thirteen months with a subsurface, islet-forming condition 

 lasting several months in addition. 



It will be seen that the floating islands of Halemaumau, by 

 their powerful influence upon the various activities of the lava 

 lake, hold a not unimportant place among the phenomena of 

 this most interesting volcano. 



Po'siliipo, Naples, December, 1912. 



