DIURNAL RANGES OF MAGNETIC DECLINATION. 



63 



values, not quarterly ones. Such are indicated by 

 brackets. 



Table III. — Mean Departures from Mean of whole. 



Period in years. 



3 



4 



5 



si 



Mean departure. 



0-6655 



0*6462 



°755 8 



0-6567 



6 1 "0242 



0*6979 

 (0-89) 

 (o-6i) 



(o # 47) 



9 



9l r 5 2 35 



10 2-1454 



ioi 2*5428 



, 2-6271 



2-2705 



4 



1 of 



Period in years. Mean departure. 



11 i 1 '^ ) 



"£ 1*8535 



"i 1*9793 



12 2*1373 



12^ 1-9607 



12^ i'54°6 



13 (o*68) 



H»- (na) 



15 ( r26 ) 



15I 1-6866 



16 1-7109 



16^ i*794 8 



16^ 1*6830 



*7 (i*35) 



10. It appears from Table III. that there are marked 

 indications of inequalities corresponding in period to 1 of 

 and to 12 years. As these periods are near together, we 

 have eliminated the influence of the 1 2 -yearly inequality 

 upon the results for 10 J, 1 of, and iof years. This gives 

 us the following corrected values : — 



Period in years. Mean departure. 



105 2-3163 



10^ 2*5629 



iof 2-2872 



The period of the inequality is thus manifestly iof 

 years. In the next place we have eliminated the influence 

 of this 1 of -yearly inequality so determined upon the 

 results for n|, 12, and 1 25 years, and have thus obtained 

 the following corrected values : — 



