PART II. POLAR MAGNETIC PHENOMENA AND TERRELLA EXPERIMENTS. CHAP. II. 



Fields of force for polar current-systems of the assumed form. 



?l = 20", ? 2 = 1 6o A" = 75- A V = o,a 1 8 /. 



435 



Fig. 182. 



Curves for constant value of P . 



I = 20", A." = 75. 



Fig. 183. 



