t) 



MAGNETIC FORCE 



21 



Increase of scale readings corresponds to decrease of force. Value of one divi- 

 sion of the scale = 0.0000365 parts of the horizontal force, or in the absolute scale 

 equal to 0.0001523. 



Investigation of th* Eleven Year (also called '/'<,, Y><<r) Period, as sliown in the 

 Changes of the Amplitude of //» S<,l<tr Diurnal V<irittti<>u of the //<>,i;:<>n/<i/ Force. — 

 The variation in the amplitude of the diurnal motion of the horizontal force is 



