292 



Dr. Norman Campbell : Experiments on 



and its capacity will be regarded throughout as part of the 

 secondary capacity C 2 . Any other capacity added to the 

 secondary circuit will be denoted by C 2 '. 



Fie. 3. 



C' z (microfarad) 

 001 002 



0OE 



009 



■010 



■Oil 



<£ 6 



































































< 



> 









•L, -01 



Li- -- 6 



S * 10" 

 49 hen 

 >-5 " 



'sec 













X>* 







y 











^ 



^ 



s 



s 

















C<- 



c/ 



-*" 















• 



• p 





y 



y . 

















j> 



• 



:V 



*/' 

















y 



X 





r'* 



















s 





i 

















ri' 1 



* 



















300 



P -4 



C| (microfarad) 



Fig. 3 gives the results of the measurements for deter- 

 mining Lj, T 2 , L/. It will be seen that the values of t 2 for 

 different values of Ci do not lie exactly on a straight line ; 

 for large values of (\ the points lie above the straight line ; 

 for values between and 0"7 mf. below it. The first de- 

 viation merely represents the fact that the self-inductance 

 increases as the period of the oscillations decreases, and is to 

 be expected ; for the eddy-currents in the core will reduce 

 the apparent permeability of the iron. Prof. Jones also found 

 that the inductances were greater for the slower oscillations. 

 The second deviation may be due to the fact that (1 . 1) has 

 been substituted for (1), but is more probably due to errors 

 in determining the period from the wave-form. The wave- 

 form is not a sine curve, but composed of at least two 

 harmonic components with different damping coefficients 

 (see fig. 2), and it is not certain that the distance between 

 successive maxima is truly equal to the period. Errors are 

 especially likely to arise from this source when, as in the 

 region between and 0*7 mf., the periods of the two com- 

 ponents are most nearly equal. 



