ON TUE EARTHQUAKE AND VOLaVNIC PHENOMENA OF JAPAN. 299 



From this ifc appears that about 41 per cent, of the shocks felt in 

 Tokio are of local origin. 



The 36 shocks which were felt in Tokio, and which shook a large 

 tract of country, may bo subdivided as follows : — 



1. Shocks which werafelt all over Tokio. These are G in number. 



2. Shocks which practically were only felt upon the hilly hard ground 

 upon the west side of Tokio. These are ."30 in number. 



From the above we may conclude that 36 per cent, of the earthquakes 

 which shake an enormous area of ground outside Tokio only shake the 

 hilly part of Tokio itself. 



From maps of shocks which shook a large area but only shook the 

 hills on the west side of the city, I find from records kept by Mr. E. J. 

 Pereira of Yokohama, which lies from Tokio about 16 miles S.S.W., that 

 at least 10 such shocks were felt in Yokohama. Had Mr. Pereira been 

 provided with a proper instrument, or had he had the assistance of other 

 observers, it is probable that he might have recorded a still greater num- 

 ber of this particular kind of disturbance. 



I. ShocJis which shook a large area of country, and the whole of Tokio. 



II. ShocJis which shook a large area of country, hut which only shook the 



hilly part of Tokio. 



