64 OLDHAM: THE CACIIAtt EARTHQUAKE OF 1 OTH JANUARY 1869. 



Yedrto (the cantonment east of Shillong) — , 



Chimneys overthrown ... 

 Native hjspital, cracks 

 Gauhati ' 



N. 



30° 



E. 



N. 



63 3 



E. 



E. 



12 n 



S. 



E. 



vr 



S. 



E 



14° 30' 



s. 



N. 



45° 



E. 



N. 



56° 



E. 



N. 



22° 30' 



E. 



S. 



5° 



W. 



Class II. 

 Barrackpore... 

 Calcutta 

 Sylket 

 Supakatti 



In the above table I have divided the observations into two classes ; 

 the first class contains those which were taken after the passage of the 

 earthquake and deduced from its effects in fracturing or overthrowing- 

 solid objects; the second class contains those observations made at the 

 time of the earthquake, and which may be called observations proper 

 as opposed to mere impressions. 



On the map No. 1 I have plotted all the observations of the first 

 class in firm lines, and it will be seen that the intersections of the lines, 

 each of which should theoretically fall on some point of the seismic verti- 

 cal, all or almost all fall close to each other and are spread over an area 40 

 miles long by 4 or 5 broad ; and if we exclude the extremes given by the 

 Sylhet church tower, the direction given by the cracks in the hospital 

 at Yeddo and the directions obtained at Silchar, the intersections are all 

 included in an area 20 miles long by about 3 or 4 miles broad. 



Among the observations of the second class, which are plotted in 

 broken lines, that from Barrackpore stands first ; it was obtained from the 

 swinging of a chandelier set iu motion by the shock. As far as value goes 

 this might well rank in the first class, and it is pleasant to find that a 

 line drawn in the direction indicated falls in the midst of the intersec- 

 tions obtained from the first class. 2 



1 I do not know the source of these observations, merely a note that suck were the 

 directions obtained, the original drawings and description having been lost or mislaid. 



- This must to a certain extent be regarded as due to chance, for at the great distance 

 of Barrackpore from the seismic vertical an error of a single degree in the observation would 

 make a great difference, and the fact that it is plotted on a map and not on globe would 

 also cause some difference in the true position of its intersection with the other lines. 



( 64 } 



