ILLUSTRATIONS OF THE ANNUAL VARIATION OF THE MAGNETIC DECLINATION. 



Black /i»^.— Mean Semiannual Diurnal Variation, March 22 to September 20. 

 Dotted line.— Mean Semiannual Diurnal Variation, September 22 to March 20. 



Fig. 2.-Toroiito. 



Fig. 3.— Hobarton. 



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