PROFESSOR CHRYSTAL ON THE DIFFERENTIAL TELEPHONE. 631 
then, lead us to the conclusion that the deadening effect will be less than it 
would have been on introducing the same resistance without induction if 
2RS? 
N'> PLR +28)’ 
i.¢., taking n?=10'(b’), R=20, S=154+9=24, L=-004, 
N’> ‘0085. 
In the actual experiment N’ was > ‘016. 
Experiment 6.—The measure of intensity here is ¢ If we denote the 
values when the neighbouring telephone coil is open, closed simply, and closed 
through a condenser of capacity X (microfarads) respectively by @, &, ¢,, then 
- ligt 
Oa = 7— 25K 4 1X2? 
il wes 
G=>7? Oe 
where g, 7, s, ¢ are obtained from the formule given for the next experiment 
by puttng M=N, and making c=0. 
For a given frequency - , the capacity for which (,=@ is (besides X =0) 
given by 
x —2.(__ NR +LON—M)n 10% 
0 = 24 2RS)+(LN— Em) 
All the quantities bemg measured in C. G. S. units except X, which is 
measured in microfarads. If X< X), then (>, if X>X,, <G; when 
X—o@, of course G=6G. 
For a given value of ni, ¢; is a maximum for a certain value of X ; if we call 
this value X,,, then eh 
1+9X, 2 = 
The following are the values of X, and X,, for 0’, g’”, e’, and 6", for the case :-— 
L=‘01, R=22, N=-‘004, S=15 (ohms and earth-quads.). 
n X, DS 
b’ 10° Sie ILS 
qi” 108 6°85 2-85 
Al 10° "81 39 
ine iLO" 083 041 
The effect of introducing a capacity is therefore as follows :—Every note 
