542 
MR, J. S. TOWNSEND ON MAGNETIZATION OF LIQUIDS. 
therefore 
and taking cr = 10 9 , we get 
ma - 3.10 7 , 
s/ 47 rma = 2 '4, 
m — '03, 
R = 37.10 9 , 
L = 67.10 6 , 
so that p — 500, and p about the same value. 
Hence we see that in equation (2), if we seek the values of q. 2 for times greater 
than ygth of a second after the primary current has been made, it is evident that 
terms having e~ mat as a multiplier may be neglected in comparison with those multi¬ 
plied by e~ pi and e - ^ 7 , so that the terms in the sum 2, reduce to 
Hence : — 
and 
B, 
y 
B m mae vH e v>t 
R , 2 (p' — mcr) R 2 
( 3 ) q s = 
4tt7’ME 
er 2 
tB m = 
B p e-P'‘ 
Bj, e -?' 1 — e-t ’ 1 
a 
Hence the quantity induced in the secondary due to the presence in the solenoid of 
liquid having conductivity cr is 
and the ratio of this to the quantity induced owing to a value of k = 10 7 is, 
p is increased when the resistance of the primary is increased, its smallest value 
being 500, which is also about the value of p'. 
