ON EARTHQUAKES IN GREAT BRITAIN. 



93 



presents the hour of the three strongest shocks, and column 4 represents the 

 degree of severity of each shock, reckoning at 10 a shock which occurred on 

 October 23, 1839. 



It will be perceived that out of the 60 shocks above recorded, felt during 

 the last eleven months, there were three occasions on which the instruments 

 were moved. From this it is evident, that the instruments are not sufficiently 

 sensitive to indicate the great proportion of the shocks now occurring, how- 

 ever well adapted they may be for registering those of a more violent cha- 

 racter which occurred in 1839 and 1840. 



II. Referring to the Report of last year (published in the last volume of 

 the Transactions of the Association) for the nature and number of the in- 

 struments which were then at Comrie or its neighbourhood, the Committee 



