THE VOLCANO ASO AND ITS LARGE CALDERA 



513 



mountains. On the east side there is no similar moat but the crater 

 borders the cliffs at the foot of the peaks Taka and Naka and is 

 separated from them by a stream channel, as shown in Fig, 10. A 

 small double rim and moat was observed by the writer in the loose 

 cinders for part of the way around the crater at the summit of Vesuvius 

 in September, 1905. 



Fig. 8. — Looking northeast into the modern crater of Aso, showing the two most 

 northerly vents and the stratified wall. These are the only active vents, the one on the 

 right being more active and deeper. Photo by Malcolm Anderson. 



HISTORY OF THE NEW CRATER 



Aso-san has been in continual activity during the historical period. 

 A detailed account of its history has been compiled by John Milne 

 from interesting contemporaneous Japanese records.^ 



The greatest eruptions of very recent times were in the v:inter of 

 1873-74, when unusual activity continued during several months 

 and ashes covered the ground to a distance of eighteen miles; in the 

 winter of 1884 when ashes were blown over Kumamoto, making it 

 so dark there at a distance of twenty-five miles that lamps had to be 



I Transactions of the Seismological Society of Japari, Vol. IX, Pt. II, 1886. 



