686 Dr. J. A. Fleming on Magnetic Oscillators 



The dotted lines represent the line joining their centres. 

 The following experiments were then made : — 



Exp. I. Effect of varying the position of the coils. — The two 

 8-feet coils of 5 tarns each were set up with centres 60 feet 

 apart. The transmitter current was 5*4 amperes. The 

 capacity in the transmitter circuit O0026 mfd. The receiver 

 was tuned to a frequency of 164,000 in syntony with, the 

 transmitter and undamped oscillations were set up in the 

 latter by the arc. The electric arc was adjusted to keep a 

 constant high-frequency current in the transmitter circuit of 

 5 '4 amperes. The arc current itself was 8 amperes and arc 

 P.D. from 260 to 320 volts. 



The transmitter was put successively in positions A, B, and 

 C, and in each case associated with receiver in positions A, 

 B, and C, and the receiver or secondary current in milli- 

 amperes being measured. The results are tabulated in 

 Table I. 



Table I. 



Transmitter 



Position. 



Eeceiver 

 Position. 



Secondary Current 

 in milliamperes. 



A 



A 



24-16 



„ 



B 



1077 



„ 



C 



20-98 



B 



A 



5-25 



„ 



B 



20-45 



,, 



C 



18-10 







A 



6-56 



ii 



B 



22-58 



ii 



O 



37-00 



1 



When the coils were in position C their planes were 6 inches 

 above the ground. 



The figures in Table I. show that when both coils were in 

 position C the receiver current exceeded that in any other 

 position, and that although the receiver current was small 

 with the coils in the positions of zero mutual induction, 

 viz. (A.B.), (B.A.), or (C.A.), it was not small in the 

 position (A.C.). 



