OF THE MAGNETIC DECLINATION. 



17 



REGULAR SOLAR-DIURNAL VARIATION OF THE MAGNETIC DECLISATION, SUMMKB HALF YEAB. 



April, 



May, 



June, 



July, 



August, 



September, 



6' 

 5 

 4 



2 



1 







1 



--2 



C' 



& 



4 

 3 

 2 

 1 

 



1 



2 



3 



6' 4 



5 5' 



4 

 3 

 2 

 1 





 1 



_2 



3 



4 1 



-5 



6' 1 



2 



3 



4 



5 



6' 



5' 



4 



3 



2 



1 







-1 



-2 



-3 



-5 



-G' 



V 



G 



4 

 3 



2 



1 





 -1 

 -2 

 -3 

 -4 



Oh. 2 



8 10 Noon 14 16 

 Philadelphia mean time. 



18 20 22 24h. 



