142 CARNEGIE INSTITUTION OF WASHINGTON. 



This is a conclusion of prime importance, for had there been any 

 uncertainty upon this one point, or liad the issue perchance turned out 

 othenvise, the integrity of the test material and the possibility of reach- 

 ing definite conclusions regarding the reactions within this particular 

 group of gases at the temperatures and under the conditions obtaining 

 in an active volcano were vitally threatened. 



The detailed study of the reaction 1 (a) was accordingly undertaken, 

 and the investigation at one temperature (1000°) may now be con- 

 sidered successfully completed. The work is to be extended to higher 

 temperatures for the purposes of obtaining confirmatory data, but there 

 is no longer any reason to anticipate possible failure, nor, indeed, any 

 undue delay in obtaining a solution for tliis very difficult problem. 



This infoniiation when obtained wall enable us to indicate the role 

 which these gas-reactions play in volcanic activitj^ like that at Kilauea, 

 and to settle the question whether or not they are to be regarded as the 

 source of any considerable portion of the energy dissipated there. 

 The prefiminary data at present available confirm the viev/ set forth in 

 Year Book No. 12, page 128, namely, that a considerable portion of the 

 energy of volcanic activity originates in the gas-reactions wdthin the 

 magma chamber and its various outlets. 



Field observations of different phases of volcanic activity have been 

 made within the year at Stromboh and Vesuvius in Italy, at Lassen 

 Peak in northern California, and at Kilauea and Mauna Loa on the 

 island of Hawaii. Lassen Peak appears now to have concluded 

 the period of explosive activity which began so unexpectedly in May 

 1914. The visible activity on the mountain during the past season 

 was confined to steam fumaroles, in which feeble traces of HCl and HoS 

 were occasionally to be detected. Perhaps in compensation for the 

 absence of explosive phenomena, the hot springs at the base of the 

 mountain afforded a splendid opportunity to study natural pyrite 

 formation in all its phases, of which full advantage was taken. 



The eruption of Stromboli during the autumn and early winter of 

 1915 proved to be unusual both in character and intensity. On several 

 occasions during nearly five months of activity, lava flowed down the 

 Sciarra from the principal vent to the sea in continuous streams. 

 Opportunities to see a stream of incandescent lava in contact with 

 water have been rare in the history of modern volcano study. Both at 

 Stromboli and at Sakurashima in 1914 liquid lava was observed to 

 continue its flow under water without explosive violence, or indeed 

 any manifestation whatever, at the surface of the water, of what was 

 taking place below. A quickly cooled porous sheath of quasi-flexible, 

 vitreous lava forms about the stream, which is sufficiently non-con- 

 ducting to confine the great body of heat within the flowing stream and 

 to release it gradually. The inmiediately adjacent water show^ed but 

 a few degrees rise in temperature. No gas-bubbles reached the surface. 



