MAGNETIC SURVEY OF GREAT BRITAIN. 



149 



shown the average daily loss of magnetism experienced in each 

 of the two intervals ; which is subsequently applied in Table 

 L,, in assigning the corresponding times of vibration in Lon- 

 don, on days when the cylinder was employed elsewhere. 



Table XLIX. 



Table L. contains the observations made by Captain Ross 

 with cylinder X, and the values of the intensity derived from 

 them. The coefficient in the formula for the reduction to a 

 mean temperature, is "00017 : the reduction has been applied 

 in the column entitled " corrected time." 



Table L. 



