98 ART. 3. — B. KOTO : 



terranean, Vesuvius manifested its activity in 1906 and 1913, and 

 Stromboli in 1907 and 1910. 



The beginning of the present century seems to mark a general 

 awakening of vulcanism after a period of comparative tranquillity. 

 In the Japanese islands, at the northwest corner of the Pacific, we 

 find also a recurrence of vulcanism. Jensen in his Samoan paper 

 says, that a volcanic island revives its activity after a cycle of 

 sixty-years. In individual volcanoes like Asama, it is likewise 

 after the completion of about 60 years ; but the regional activity 

 of deep origin revives after the double length of the sixty-year 

 cycle. The following may illustrate the case : 



The above table shows that one period of the regional activity 

 was completed within 16 years, during which the centres of dis- 

 turbance were regularly and alternately shifted to and fro from 

 Kyûshù to Central Japan, or the reverse, thus illustrating the 

 typical case of a ' sympathy of alternation between two region s.'^^ 



After a lapse of 120 to 135 years, or about the double length 

 of the sixty-year cycle, the same regions are now being disturbed 

 by vulcanism, viz., Asama, Yaké-daké, Oshima, and the two 

 volcanic islands of the Benin group, i.e., Iwo-jima and Tori-shima 

 (Aug. 1902) in Central Japan ; and the Tori-shima (May 4 [April 

 11], 1903) of the Eyûkyû chain,"^ Kirishima (Jan. 8, 1914), the 

 Iwô-jima^^ or the ' sulphur island ' (of Kagoshiraa Prefecture, Feb. 



1) See page 93, and footnote 3. 



2) See pages 4. 3) See ])ages 5, 21 an.l 92. 



