186 F. OMOEI AND K. HIRATA : 



undulations, whose average period was 0.93 second in the (EW), 

 and 0.87 second in the (NS), and whose maximum motion was 

 2a=3.0 mm., T=1.2 seconds. 



33. Eqke. No. 25. The 19th May, 1898 ; 9.50.40 a. m. 

 Intensity, very slight. This was a small local shock, whose 

 origin was at about 43 km. S of Miyako. 



The duration was only 10 seconds, the motion consisting 

 entirely of small ripples of an average period of 0.069 second. 



34. Eqke. No. 26. The 31st May 1898; 1.3.22 a.m. 

 Intensity, slight. The origin was at about 80 km. ESE of 

 Miyako. 



The duration of the H.M. was 77 seconds, and that of the 

 V.M. 43 seconds. The motion consisted of small ripples super- 

 posed on slight slow undulations, there being no prominent 

 maximum movements. 



The preliminary tremor, whose duration was 7.7 seconds, 

 consisted of very fine ripples. 



The principal portion consisted of ripples, whose maximum 

 2a was 0.1 mm. in each component, and whose average period 

 was 0.085 seconds in the (EW), 0.085 second in the (NS), and 

 0.07 second in the (V) ; the period of the slow undulations, 

 whose amplitude was very small, being 1.5 seconds in the 

 (EW). 



35. Eqke. No. 27. The 3rd June, 1898 ; 3.22.10 p. m. 

 Intensity, slight. This was a small shock, whose origin was 

 at about 52 km. SE of Miyako. The duration was 25 seconds. 



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

 (NS), traces of the V.M. being also present. 



The duration of the preliminary tremor was very short, 

 and the maximum motion of 0.4 mm. occurred immediately after 



