AFTERSHOCKS IX. 



l 7 



Date. 



Time. 



Nov. 

 28 



39 



30 

 Dec. 

 2 



Dura- 

 tion. 



Nature. 



14-37 



1 s. 



15-20 



* »> 



19-19 



2 „ 



10-34 



* >> 



II-II 



1 y> 



16-50 



* s> 



15-0 



9 „ 



16-38 



■ y> 



■9-51 



* >> 



8-30 



1 >> 



8-40 



■ >> 



8-54 



'■ u 



7-34 



18 „ 



6-35 



1 „ 



7-5 1 



3 M 



feeble. 



slight, 

 feeble. 



slight, 

 feeble 



Date. 



Time. 



Duia- 

 tion. 



Nov. 

 5 



i3-4o 

 i5-4o 

 14-9 



14-15 

 17-8 

 1 9-2S 



•3-34 



17-40 

 ;8-i7 

 10-34 

 15-0 



H)-o 



17-55 



18-19 

 20-48 



s. 



Nature 



feeble. 



slight, 

 feeble. 



slight. 



feeble. 



Date. 



Dec. 



9 

 10 



12 



13 

 »4 



15 



Time. 



Dura- 

 tion. 



Nature. 



21-5 



2 



s. 



7-0 



1 



»> 



7-9 



10 



M 



13-12 



1 



>> 



20-30 



1 



J> 



7-21 



6 



>» 



7-5o 



2 



J> 



11-40 



1 



» 



M-25 



2 



») 



15-54 



1 



>> 



18-11 



1 



>> 



8-45 



3 



»» 



14-0 



l 



it 



18-6 



1 



» 



"-45 



1 



it 



feeble. 



j> 

 slight, 

 feeble. 



slight, 

 feeble. 



IX. 



List of earthquakes recorded by the pendulum seismograph at 

 Skillong from 4th August i8gj to jrst December i8g8. 



This instrument was constructed under the supervision of Mr. La Touche 

 and set up in the office of Mr. G. K. Watts, Executive Engineer, by whose direction 

 the records were kept. The instrument is a simple pendulum with a pointer 

 giving an amplification of about 5 times to record the movements on a piece of 

 smoked glass. The movement of the pendulum is not controlled in any way, and 

 the diagrams are consequently a combination of the movement of the ground 

 and the motion communicated to the pendulum ; they serve, however, to give 

 a fair idea of the comparative range "of motion in the earthquakes recorded by the 

 instrument. Besides these there were at least four or five times as many, distinctly 

 sensible to any one sitting or lying down, but not of sufficient range of motion 

 to affect the instrument. 



The range of motion is approximately the actual movement of the ground in 

 millimetres (25 mm.= about 1 inch). Where the measurement is given as 'i, it 

 means practically that the movement was visible but too small to measure. 

 Where two shocks are bracketed together it means that the recording surface was 

 not renewed between them and that the records of the two or more shocks cannot 

 be separated from each other. 



( 17 ) 



