MAGNETIC SURVEY OF GREAT BRITAIN. 



167 



Table LXVII. 



Cylinder L (Z») . 



Correction of the Results. — ^The first correction that seems 

 to be required is in the series of results obtained in the North 

 of Ireland, in the autumn of the year 1834. On a comparison 

 of the times of vibration of cylinder L (Jj) in Dublin, at the com- 

 mencement and end of that series, it will be seen that the mag- 

 net sustained a loss of force ; and an attentive examination of 

 the other parts of the series shows that this loss occurred im- 

 mediately previous to the final observation in Dublin. This 

 fact will be seen very evidently by means of the following table, 

 which contains the corrected rates of the two cylinders, and the 

 deduced values of the intensity compared with the intensity in 

 Dublin at the time of the initial observation. Tlie results ob- 

 tained with the two cylinders present a very close agreement, 

 except in the final observation. 



M 2 



