﻿THE 



GEOLOGICAL MAGAZINE. 



NEW SERIES. DECADE II. VOL. IV. 



No. v.— MAY, 1877. 



oiaiC3-zisrj^L j^iaTioxiiES. 



I. — A Visit to the Volcano or Oshima. 



By Professor John Milne, F.G.S., 

 Imperial College of Engineering, Kogakurio, Tokei, Japan. 



LOOKING at a map of Asia, or, still better, at a map of Japan, 

 there will be seen a string of islands stretching from near the 

 entrance of the Bay of Yedclo in a more or less southerly direction 

 towards the Bonins. It is very probable that all these islands are 

 of volcanic origin. "With the exception of one or two of them, 

 which within the last few years have given off a few curling wreaths 

 of steam, they might strictly be defined as being dormant, having 

 given vent neither to fire nor smoke within the history of their 

 inhabitants. In this respect they are similar to many of the volcanic 

 cones in Japan, with which they are also probably coincident in age. 

 A short time ago, however, during the first week in January, a great 

 change was observed in the most northern of these islands, which is 

 called Oshima. Ships coming into Yokohama brought news that 

 the island was on fire. One captain reported that flames 200 feet 

 in height were seen. Although Oshima was an island which three 

 years previously had been giving out clouds of smoke, and seven 

 years before that had been actually in eruption, it was thought by 

 many that the conflagration was due to the burning of grass or 

 wood, and it was not till some days had passed that the true state 

 of afi"airs became fully recognized. 



After some trouble, a party was organized and a steamer engaged 

 to visit the scene of the eruption. We left Yokohama on the after- 

 noon of the 19th January, and in the evening reached Kanasaki, a 

 village situated at the extremity of the peninsula upon the south side 

 of Yeddo Bay. After staying here a few hours, we continued our 

 course, and reached the island shortly after daybreak on the follow- 

 ing morning. During the night there was an uninterrupted view of 

 the volcano, from the summit of which huge clouds of steam, lighted 

 np with the glow from the crater beneath, could be distinctly seen. 

 It was a veritable " pillar of fire." 



The island, which is about eight miles long, and very mountainous, 

 has only one harbour, and this is useless but for vessels of small 

 size. It is called Habu, and is situated near the S.E. corner of the 

 island. It is entered by a narrow gap in cliffs of stratified and con- 

 torted agglomerate. This entrance is shallow, but the harbour itself 



DECADE II. — VOL. IT. — NO. T. 13 



