!18 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



marked " 74 = 9," requiring X3/X to be 1.0. This curve is almost flat 

 on top and for this condition tuning with Circuit IV is impossible. 

 There is left here, as with all the curves of this figure, the alternative 

 of leaving Circuit IV fixed at its best value and tuning with Circuit III. 

 This is Case II, which we presently come to consider. It is proposed 

 first, however, to present a new set of curves under Case I with a 



"-^. 



> 



Figure 9. Curves similar to Figure 8, but with % = .l, t = .30. 



larger damping factor (773) in Circuit III, corresponding to the antenna 

 circuit. 



Cai^e I {continued). Assuming r = .30, 773 = .1, a^id t]i various. — 

 The curves for these conditions are plotted in Figure 9 for only the 

 short-wave adj ustment. The corresponding long-wave adjustments are 

 presented in Figure 10. 



The Equations and Computation of Case II. — It is now proposed to 

 set Circuit IV at its best value, with any given constants of circuits, 

 and to tune with Circuit III. The equations giving the current in 

 Circuit IV for various values of wave length of Circuit III, are ob- 

 tained from (41) and (44) by a simple interchange of subscripts, — 

 giving 



(48) (4^) 



\ -^ max max J 



(k 



4 xm'm 



