470 



TABLE 496.— THE FIRST EIGHT GAUSS COEFFICIENTS OF THE EARTH'S 

 MAGNETIC POTENTIAL (V) EXPRESSED IN UNITS OF 10- 1 cgs 



Source Epoch 



Gauss 1835 



Erman-Petersen 1829 



Adams 1845 



Adams 1880 



Fritsche 1885 



Schmidt 1885 



Dyson and Furner 1922 



Afanasieva 1945 



Vestine and Lange. . . . 1945 



fea 2 



+ 157 

 + 146 

 + 135 

 + 149 

 + 142 

 + 149 

 + 84 

 + 48 

 + 54 



TABLE 497.— SPHERICAL HARMONIC COEFFICIENTS OF THE AVERAGE 

 ANNUAL SECULAR VARIATION EXPRESSED IN UNITS OF lO 5 cgs 



Source Epoch gj> g 1 x V 



Dyson-Schmidt 1922-1885 +20 - 1 - 1 



Bartels 1920-1902 +42 -9 +12 



Carlheim-Gyllenskold .. 1920-1902 +13 + 4 



1912.5 +25 +1 — 7 



Vestine and Lange J 1922.5 +28 +4 —7 



1932.5 +23 +1 — 5 



1942.5 +9 +2 +1 



The magnetic moment of the earth (epoch 1922) = 8.06 X 10 28 cgs. 

 n ., , /Latitude 78.6 N. 



Geomagnetic north pole \ Longitude 289.9 E. 



Geomagnetic south pole { iSng^ude 109.9 E. 



TABLE 498.— COORDINATES OF NORTH MAGNETIC POLE 



* For authorities, see bibliography, p. 501. 



t Based on the above position for 1904.5 with reduction for secular change. 



SMITHSONIAN PHYSICAL TABLES 



