144 



MR. R. D. OLDHAM ON THE PROPAGATION OF 



and corresponds to the maximum rather than the commencement of the same phase at 

 Padua and Catania, while the recorded times of commencement of the slow undula- 

 tions at Ischia and Catania are so much in advance of these at the other stations thai 

 they must be regarded as due to an earlier phase, while the undulations were still too 

 small to be generally registered. 



There were two other shocks registered on the same day in Japan, and presumably 

 originating from the same, or practically the same, centre. Making the same time 

 allowance the times of origin would be 19' 1 13'25 m and 22 h 58 of 15th June. From 

 the records published in the ' Boll. Soc. Sismol. Ital.,' vol. 2, Part II., the following 

 details are extracted. 



Shock of 19 h 13'2 ni . 



Padua. 19 h 28'" 41 s commencement of rapid oscillations, at 20 h 3 m 33' the slow 

 undulations commence, which end at 20 h 22 m 43'. 



Rocca di Papa. Commencement 20 h 3 m , maximum 20 h 6 m , end 20' 1 24" 1 on N. S. 

 component; on E. W. commencement 20 h 4 m , maximum 20 h 6 m , end 20 h 17 m . 



Rome. The first distinct oscillations at 20 h 4 m 15' on N.W. S.E. component, 

 maximum 20 h 6 m 55*, end 20 h 22 m 30'. On the other component the commencement 

 was at 20 h 8 55', end 20 h 25 10 s . 



Ischia. 19' 1 38 47 s commencement on both the horizontal pendula ; oscillations 

 of a period of 22 '6 s commenced at 20 h 3 m 7 s on E. W. component and at 20 h 3 m 33' on 

 N. S. ; maximum at 20 h 6 m 47 s . 



Summary of the above Times, in minutes, after 19 h . 



Shock of 22 h 58 m . 



Padua. 23 h 13'" 27 s commencement of diagram, at 23 h 13 46" the slow undula- 

 tions began, which terminated at 24 h O m 24'. 



Rocca di Papa. 23 h 46 ra commencement on N. S. component, 23 h 49" maximum, 

 end 24 h . On E. W. component the commencement was 23 1 ' 48 m , maximum, 23 h 50 m 

 30", end about 24 h . 



Ischia. Commencement of disturbance on E. W. component 23 h 23 m 23 s ; the blow 



