ON THE EARTHQUAKE A\D VOLCANIC PHENOMENA OF JAPAN. 110 



One of the most interesting of these disturbances is that which was 

 recorded at three stations, at about 18 hours, on October 27. The origin 

 of this was near to the Antipodes of Japan, in the Argentine E.epublic. 

 In the shaken district Dr. E. von Rebeur-Paschwitz tells nie that the mean 

 velocity of progagation was about 1-2 km. per sec. Mr. C. Davison tells 

 nie that it reached Europe to be recorded at Rome with a mean velocity 

 for the large motion, of 3-17 km. per sec, the preliminary vibrations 

 having a velocity of 10-38 km. per. sec. These latter movements reached 

 Charkow and Nicolaiew with velocities of 11-47 and 9'17 km. per .sec. 

 If the record J for Japan can be assumed to be approximately correct, 

 then the movements recorded in Japan, if they were propagated over the 

 .surface of the earth, reached that country with a mean velocity of 19 km, 

 per sec' The figure is reduced from the record of K. 



KiG. 14. 



III. — Description of a Catalooue of 8,331 Earthquakes recorded 

 IN Japan between January 1885 and December 1892. 



(a) History of the Catalogues. 



In order to determine the number of shocks which ai'e felt per year in 

 Japan, and to obtain some general idea as to their distribution, in 1880, 

 with the assistance of Mr. Toshiwo Nakano, the present writer communi- 

 cated with residents in all the principal towns of the Empire, asking them 

 to furnish information about the seismic activity, both past and present, 

 of the districts in which they resided. An examination of the replies 

 which were received led to the conclusion that on the average there were 

 three or four shocks per day, or for Japan alone there were as many shocks 

 per year as Professor Heim had calculated, for the whole globe (' Trans. 

 Sois. Society,' vol. iv. p. 30). In the following year, in order to determine 

 the extent of country which was shaken by a given shock, bundles of post- 

 cards were sent to very many towns and villages within a range of about 

 100 miles of Tokio, with a request that every week one of these cards 

 should be returned with a statement of the earthquakes which had been 

 felt. The result of these communications showed that nearly all the 

 shakings which disturbed Tokio came from the east and north, and seldom 

 passed beyond the mountain ranges to the west and south. These facts 

 having been established, the barricade of postcards was extended north- 

 wards until it reached Sapporo, which is about 450 miles north from 

 Tokio. With this system, between October 1881 and October 1883, 387 

 earthquakes were recorded, for each of which a map was drawn showing 

 ' They may have passed through the earth with a velocity of 13 km. per second. 



