206 



PIERCE. 



The last two columns contain corresponding values of the attenua- 

 tion constant a computed by the use of the exact equation (6), for the 

 case of R/Ro= .1. For R = the value of a is zero throughout the 

 range of the table. 



In the table the values of R are specified by specifying values of 



R/Ro, where Ro= V Z/CV Only two values of R/Ro (namely, zero 

 and .1) were employed in computing the tables. The case in which 

 the ratio is zero is a case of zero attenuation, while the case with the 

 ratio . 1 is a case of much higher attenuation than would arise with 

 coils built with a reasonable effort to keep the ratio of resistance to 

 inductance small, so that the table gives extreme ^'alues. 



Curves of the data of the table are presented in Figures 4, 5 and 6. 



.4 



.e /. tZ 14 



Figure 4. 



/-6 1.8 ^0 X'l «'/ 



12. Comparison of Line of Mutual Inductance equal to One 

 Tenth of Self Inductance with Line of Zero Mutual. — By refer- 

 ence to the curves of Figures 4 and 5 it is seen that the range of values 

 of CO for which the time retardation T per section is within a given 

 percentage of constant is much larger in the case M = . IXi than in 

 the case M = 0. With M = .\L\ the range of frequencies over which 

 T is within one percent of constant is three times as great as when no 



