466 



Dr. C. Davison on the Diurnal 



6. Japan.— Prof. J. Milne, "A Catalogue of 8331 Earth- 

 quakes recorded in Japan between 1885 and 1892." Seismol. 

 Journ. of Japan, vol. iv. 1895, pp. i-xxi., 1-367. 



Duration of record, 1885-1890. Number of earthquakes, 

 1175 ; in winter, 578 ; in summer, 597. 



Prof. Milne's great catalogue includes all the earthquake- 

 records collected by the Imperial Meteorological Office at 

 Tokio. A large number of these were obtained by means of 

 seismographs, but unfortunately the particular shocks so 

 recorded are not indicated. For my present purpose, I have 

 made use only of those in which the time of occurrence is 

 given in hours, minutes, and seconds : for these, Prof. Milne 

 informs me, were certainly registered by seismographs. As 

 many others may, however, be omitted by this mode of 

 selection, it is obvious that the results will not compare in 

 value with those obtained from the Tokio record. I have 

 excluded the shocks occurring during the last two years em- 

 braced by the catalogue on account of the great number that 

 followed the Mino-Owari earthquake of 1891 (see §§7, 8):— 





Whole year. 



Winter. 



Summer. 



Harmonic 

 Component. 















Ampl. 



Epoch. 

 h m 



Ampl. 



Epoch. 



h m 



Ampl. 



Epoch. 

 h. m 







A.M. 





A.M. 





P.M. 



1st (24 hours) ... 



•147 



11 53 



•239 



11 50 



•061 



2 



2nd (12 hours) ... 



•004 



9 8 



•035 



9 48 



•028 



3 58 



3rd (8 hours) ... 



•064 



6 31 



•045 



6 12 



•083 



6 40 



4th (6 hours) ... 



•100 



2 39 



•067 



2 8 



•146 



2 53 



After- Shocks of Japanese Earthquakes. 



7. Prof. F. Omori, Journal of the College of Science, Imp. 

 Univ., Japan, vol. vii., 1894, pp. 126-138, 157, 178-191, 194. 

 I am indebted to Mr. K. Nakamura, Director of the Central 

 Meteorological Office, Tokio, for the hourly numbers of shocks 

 recorded during each month by a Gray- Milne seismograph at 

 Gifu from October 1891 to December 1893, and at Nemuro 

 from March 1894 to February 1895. 



Duration of records : Kumamoto, July 31-Aug. 13, 1889 ; 

 Gifu and Nagoya*, Oct. 29-Nov. 10, 1891; Chiran, Sept. 

 8-21, 1893 ; Nemuro, March 1894. Number of earthquakes: 



* It should be mentioned that a few of the hourly numbers of shocks 

 at Gifu and Nagoya given in the table differ by one or two units from those 

 given by Prof. Omori. The figures in the table are obtained from the lists 

 of shocks given in Prof. Omori's tables xi. and xii. 



