OF THE MAGNETIC DECLINATION. 



This table shows plainly the relation of the mean hourly position of the magnet 

 of each month to its general mean position, after the separation of the larger dis- 

 turbances, and also, by running the eye along any horizontal line, the solar-diurnal 

 variation for each month. It does not, however, show distinctly the annual in- 

 equality, on account of the changes in the numbers by the secular change. To 

 eliminate the effect of this change, each hourly normal has been compared, in the 

 following table, with the corresponding mean monthly value, as given in the last 

 right-hand column ; the sign + indicating a westerly direction, and an easterly 

 direction, 1 of the- north end of the magnet from the mean monthly position. The 

 scale divisions have been converted into minutes of arc. 



1 The sign -f being generally taken to signify west declination, it has been retained to indicate a 

 movement of the north end of the magnet to the west. 



