Curves of the Diurnal Variations of Magnetic Declination, as shown by a Needle freely suspended in the direction of the Magnetic Inclination, at Ten Stations betwixt Latitudes 56 N.&WS., for each Month of the Year 



Deduced by J. A.Brouh, F.RS. 



JANUARY MARCH MAY JULY SCPTCMBEH NOYEMBCR 



fJ-ATJSXUV 



J2_I4_ 16 18 20 22 1 4 6 8 10 Ig I4_I6 12 1 4 16 IB 2 22 2 4- G 8 10 12 I* 16 12 14 16 IB 20 22 2 4 G 8_10_12 14 16 12 14 16 IB 20 22 



14 16 12 '4 16 IB 20 22 _Z 4 6 8 10 12 14 ^6 12 14 16 18 20 22 2 



6 8 10 12 14 16 



Ascending Curves denote, increasing Easterly Declination;. One. Division = O '-25 / One, Inch ■= One minute. 



