1SUSE1STS. DISTRIBUTION OF INTKNSITY, KTC. 



87 



The vertical motion and tilt record from Bombay is as follows :— 



The commencement of the Burma quake is timed at 2 hours 29-1 minutes. 



„ ,, ,, „ of the previous day at 23 hours 12-3 minutes. 



The times of commencement as recorded by this instrument are 

 almost always earlier, but in a few cases they are either simul- 

 taneous or slightly later than the commencements recorded by the 

 horizontal pendulum seismographs (PI. No. 9). 



For the purposes of this calculation 1 take 8 hours 5-4 minutes 

 Rate of Propagation 15 seconds, as the probable time for the be- 

 oftheShook. ginuing of the shock at the epicentre. 



The times of commencement of the Large movement in the 

 Indian seismographio records of the earthquake are as follows : — 



1 1 ' mis. .Uiiiutrs. Seconds. 



Bombay 9 8 24 



Simla 9 5 39 



We therefore have : — ■ 





Distance in 

 miles from 

 epicentre. 



Seconds 



during 

 transit. 



Deduced 



rate in 





miles per 

 second. 



Bombay ...... 



1,501 



849 



084 



1-83 



Simla ....... 



1,350 



1-97 







Mean 



1-90 



The times given are all reduced to Burma Standard Time. I 

 am indebted to my colleague Mr. C. S. Fox for the calculation of 

 the distances given above. 



THE ISOSEISTS. DISTRIBUTION OF INTENSITY AND 

 CHARACTER OF THE SHOCK. 



The intensity of an earthquake is beat inferred from the 

 records of instruments designed for the purpose, and stationed m 

 the dist liets over which the shook is felt. Owing to the absence 

 of such instruments in Upper Burma we have to fall back upon 

 the more general method, by estimating intensities from the effects 



