W. A. Norton on Molecular Physics. 73 
annual resultant of the one set of components will constitute a 
current from E. to W., which will be equal to the sum of the in- 
dividual components; while that of the other set will be equal 
to the excess of the currents that run from N. to S. over those 
that run from S.to N. These general facts being borne in mind 
‘ N ing to the 
declination of the needle; except when the declination is easterly, 
_— sides of the point of maximum declination 
ss } . an 7 f 
now does throughout the United States. It ps then, that 
