ON SEISMOLOGICAL INVESTIGATIONS. 



73 



Fig. 5 indicates that the mean duration of an earthquake increases 

 with the distance to which it is propagated. This in turn is dependent 



Fig. 5. 

 Mean Duration of nercral FartJiquaJtes and the Dhtance they hare travelled. 



O 15 30 45 60 75 90 705 720 

 Minutes. 



upon the intensity of tlio initial impulse. Fig. 4 leads to similar 

 conclusion^. 



