]\rAGXETrC SUEVEY OF JAPAN FOR THE EPOCH 1S9.").0. 107 



Fig. 13. 



The Eirtli Magnetic Field after deducting tlie Field 

 due to the Mean j\lao;netization 188.J. 



Full lines show eqiuil residual upward magnetic force-, and dotted lines 'those of down- 

 ward forces, iigures indicate intensity in 1000 y, or, .01 C.G.S. unit-;, the arrow lines 

 masrnitnde and direction of the residual horizontal forces. 



tlie distribution represented by the second and higher harmonics 

 in Gaussian expansion. It is reconstructed from Bauer's reduc- 

 tion with slight modifications as to the convension of representing 

 tliose magnitudes.'" We observe in this maj^, a center of 

 attraction not far from the epicenter now found. Bauer gives 

 the position of this point, 



Longitude llO'^E., Latitude 35°N. and the intensity of the 

 residual vertical field —.139 C.G.S. units {I.e. downward). 



The accidental agreement of these results, however, should 

 not be looked upon as showing any possible existence of such 

 a source. If this were really the case, there must be large 

 variational anomalies in middle of China. liecent observations 

 at a few points near this region by Sinzyö, Otani and Yamagawa 

 give no indication of such : — 



* Terrestrial Magnetism Vol. IV p. 44, 



