520 



EQUATIONS OF CONDITION FOE FINDING 



In these equations the expression of the Magnetic Forces in terms 

 of the Magnetic Constants for a given belt of latitude is equated to the 

 corresponding expression called the absolute term which is derived from the 

 observations taken in that belt of latitude. 



The logarithms and the signs ( + or ) of the coefficients of g or 

 h in the equations are given in the tables. The numerical values of the 

 absolute terms are given for 1845 and for 1880 for the g and h equations. 



, = 0. 



n ODD. 



