96 ART. 3. — B. KOTÔ: 



D) Summary and Conclusion.— The writer will now brin<j: 

 his diary on the eruption of Mt. Sakura-jima to a close. Its 

 activity is imperceptibly diminishing in intensity, but it will be 

 long^^ in coming to final rest. In the Samoan eruption of 1905-6, 

 the basaltic lava was moving for a year and three months, so the 

 present convulsion of the andesitic Sakura-jima will also be com- 

 pletely tranquillized in the near future, although it may last 

 longer, considering the larger dimension of its vents and its greater 

 magnitude of vulcanicity. The Yunohira or western ventholes 

 started first (Text-fig. 14 a [2]), breathing only feeble fumes in 

 April, 1914 ; while the late-born Nabé-yama or eastern vents 

 (Text-fig. 14 ^ [3]) were still keeping on their detonations, though 

 moderately, at the same time throwing up curdy black smoke. 

 The vulcanism is greater in scale on the east than on the west 

 side. 



The following is a summary of what is already stated in 

 the diary and the conclusions arrived at both from field observa- 

 tions and laboratory studies. 



i. Predisposing Causes. — The eruption at Sakura-jima was not 

 an accidental explosion of pent-up steam and gases near the old 

 crater-pit of a slumbering volcano. On the contrary, the cause 

 lay far and deep. In the earth's history, we find a series of long 

 periods of epeirogenic movement alternating with long periods of 

 stabihty, responding to the varying conditions of stress-accumula- 

 tion in the interior or to the glidinsr of the outer shell over tlie 



1) Tlie writer worked out the first part of the manuscriist after the second trip in 

 Ai^ri), 1914. Complete records are not at hand on the dechning and closing phase of the activity. 

 In October 1915, i.e., after twenty-two months, one of the vents was said to have been still 

 l>eriodical]y exploding and throwing up the lava plug solidified within the venthole after the 

 Vulcanian type. The subterranean condition has not yet come to rest. The tremors related in 

 their origin to Sakura-jima and recorded by a seismometer at Kagoshima numbered 667 in 

 Jaimnry, 107 in February, and ;}97 in ^Nlay, 1916. — Nofe durimj Press. 



