ON THE EARTHQUAKE AND VOLCANIC PHENOMENA OF JAPAN. Ill 



is observed that pendulum A is steady on dull wet days, but on warm 

 days the daily curves are well defined. Farther, although A and E move 

 at the same time, they move in opposite directions, but each usually moves 

 towards the side from which the greatest load is being removed by 

 evaporation. 



III. The Tokio Earthquake of June 20, 1894. 



On June 20, at a few minutes past two in the afternoon, Tokio, 

 Yokohama, and the surrounding districts were shaken by an earthquake 

 which was more violent than any which has been recorded since 1855. 

 On June 25 it was reported that in Tokio alone 33,940 buildings had 

 suffered damage, some being entirely ruined, 140 pei'sons had been 

 wounded, and that 26 had been killed. In Yokohama, where many 

 chimneys fell and houses were unroofed, 6 people were killed. When 

 statistics are completed and it is known what has happened in other 

 places these numbers will be increased. Small fissures were formed in 

 the ground at Tokio in 96 places, many walls were shattered, while stone 

 lanterns and tombstones were overthrown, twisted, or deranged. 



The following facts are taken or deduced from the records obtained at 

 the Central Observatory and the University Laboratory, both of which are 

 in Tokio, at a distance of about 1^ mile from each other. To these are 

 added observations from the Hitotsubashi Observatory, which is situated 

 on soft ground lying between the Central Observatory and the University, 

 at which places the ground is comparatively hard. 



At the University for the first 10 seconds the horizontal motion was 

 slight, when it suddenly became severe, reaching 80 millimetres. The 

 severe motion continued for about a minute, during which time there 

 were more than 10 pronounced movements. As the range of motion was 

 outside the limits of seismographs with multiplying indices these were 

 deranged or broken, and complete diagrams were only obtained at the 

 University and Hitotsubashi, where there are seismographs without such 

 indices, the recording surfaces for which are only set in motion at the 

 time of violent disturbances. Until the diagrams have been carefully 

 analysed I am inclined to think that the recorded horizontal motions may 

 represent the angles through which the seismographs have been tilted, 

 rather than the range through which a given point suffered horizontal 

 displacement. 



Assuming for the present that these quantities are what they are 

 represented as being, then at the University and at Hitotsubashi the 

 maximum accelerations were respectively 400 and 1,000 millimetres per 

 sec. per sec. In the Nagoya-Gifu earthquake of 1891, when nearly 10,000 



