170 F. OMORI AND K. HIRATA : 



9. Eqke. No. 6. The 1st September, 1896 ; 2.55.15 p. m. 

 Intensity, slight. This was one of the after-shocks of the eqke. 

 No. 4, the origin being probably situated in the same position 

 as that of the latter. 



The duration of the H.M., as well as that of the V.M., 

 was 48 seconds. 



The motion was much greater in the (EW) than in the 

 (NS), and consisted of very small ripples superposed on slow 

 undulations, whose maximum motion was 0.4 mm. in the (EW), 

 0.1mm. in the (NS), and 0.14 mm. in the (V). As the rota- 

 tion of the record-receiving drum was unfortunately not pre- 

 fectly good, the period can not be determined accurately. 



10. Eqke. No. 7. The 5th September, 1896 ; 11.9.25 p. m. 

 Intensity strong. The origin of the earthquake was in the 

 Pacific, probably at about 130 km. ENE of Miyako. 



The duration of the H.M. as well as that of the V.IM. was 

 35 seconds. The motion, in which V.M. was present to a pro- 

 portionally large amount, was active for the first 5 seconds and 

 then became abruptly small. The maximum motion of the 

 ripples, which were superposed on slow undu rations, was 3.6 mm. 

 in the (EW), 3.0 mm. in the (NS), and 0.4 mm. in the (V). 



As the rotation of the record-receiving drum was unfor- 

 tunately not perfectly regular, it is impossible to estimate accu- 

 rately the periods of vibration. 



11. Eqke. No. 8. The 7th February, 1897; 4.35.30 p.m. 

 The earthquake consisted of two shocks with a time interval 

 between them of about 1 minute, the intensity of the first shock 

 being weak, and that of the second being strong. In these two 

 shocks, the maximum motions in the^(EW) were respectively 

 4 and 2| times greater than those in the (NS), the V.M. being 



