56 GAUSS AND WEBER ON TERRESTRIAL MAGNETISM. 



Mean value of the Westerly Magnetic Declination at 

 Gottingen. 



1834. March, second half 



April 



May 



June 



July 



August , 



September 



October , 



November 



December 



1835. January 



February 



March 



April 



May 



June 



July 



August 



September 



October 



November 



December 



1836. January 



February 



March .'. 



April 



May 



June 



July 



August 



September 



October 



November 



December 



1837. January 



February 



March 



8, A.M. 



18 38 160 

 36 6-9 



36 28-2 



37 40-7 



37 57-5 



38 481 



36 58 4 



37 18-4 

 37 38-4 

 37 54-8 

 37 51-5 

 37 3-5 

 34 47-5 

 32 57-7 

 32 13 4 



32 56-4 

 34 8-0 



34 12-4 



33 21-2 

 33 230 

 36 15-3 



35 25-9 

 35 24 

 33 26-7 

 31 1-4 



26 32-9 



28 0-8 



27 35-1 

 26 54 2 



25 42-4 



26 14-6 



27 34-0 



29 21-0 

 29 13-7 

 27 35-3 

 27 356 

 25 44-2 



1, P.M. 



18 46 40-4 

 47 3-8 

 47 15-4 



47 59-5 



48 190 



49 110 

 46 32-3 

 44 47-2 



43 43 



41 32-7 



42 14-4 



42 29-4 



44 55-2 

 46 31-6 



45 17-1 

 44 41-3 

 44 42-8 



46 56-8 

 44 27-6 



43 5-3 

 43 49-5 

 40 19-1 



40 34-6 



41 152 

 43 16-4 



43 42-6 



44 37-2 



42 52-4 

 42 260 

 41 450 

 40 59-6 

 40 32-8 



36 54-3 



35 46-8 



37 46-2 



36 28-3 

 39 4-2 



Some combinations of these observations may now be noticed. 



The difference between the declination of the morning and 

 afternoon has one sign all through in the monthly means ; the 

 dependence of its magnitude on the season of the year ^\'ill be 

 perceived in the following tabular view : 



