186 Mr. Appleton and Dr. JB.van der Pol on a Type of 



oscillation characteristic in which these terms are excluded 

 by means of a simple graphical method. A typical oscil- 

 lation characteristic obtained experimentally is shown in 



M 



fig. 3,. for which the value of -p is 0*57 and the steady 



electrode potentials such as to give a case of' marked oscil- 

 lation hysteresis. 



Fig. 3. 



~L\ ~ 



I 2 





































V ao ^IOO 

 V g0 = -8 1 



volts. 



'o/ts 







































































































1 



O (. 







-40 -20 20 40 



Variable Anode Potential f\s) /"n Volts 



60 



We have eliminated the even part in the function repre- 

 senting this curve by folding the curve about the i axis and 

 then again about the v axis, and taking the mean of the two 

 ordinates occurring in the quadrants II. and IV. The result 

 is shown in fig. 3 A. The general agreement between the 

 differential coefficient of this symmetrical curve which re- 

 presents the relation i = yjr(v), and the curve of No. 3, fig. 2, 

 is clearly apparent if we bear in mind that %'(v) is equal to 



L C 



We are now prepared to discuss in greater detail the 

 quantitative results previously obtained for our example of 

 Case 3 of the table and No. 3 of fig. 2. 



Fig. 4 shows a graphical representation of these results, 

 in which the square of the amplitude is plotted as a function 



