

Air-Blast upon the Spark Discharge of a Condenser, 68?) 



means of calculating D or the sum o£ the decrements of the pri- 

 mary circuit &! and that of the cymometer S 2 ,this last including 

 that due to the resistance of the hot-wire ammeter. A reson- 

 ance curve was then drawn and a series of horizontal intercepts 

 measured off near the peak of the curve, and the ordinates of 

 these intercepts also read off on the curve (see fig. 1). The 

 half of the length of the intercept is taken as the mean-value 



n 

 of 1— ™ and the corresponding ordinate expressed as a 



fraction of the maximum ordinate of the curve is taken as 

 a/ A, and from this last the function tta/ - is calcu- 



V A." — a 



lated and the product of these two quantities, viz., 



( 1 ~I) ,r '\/S 



gives us D = Si + Sg, or the sum of the decrements of the 

 primary and secondary circuits. 



The resonance curves are plotted to such a scale that 

 the maximum ordinate representing A is unity, and the 

 abscissa of that ordinate representing N is also taken 

 as unity. 



The complete set of observations for the 1 mm. spark-gap 

 when subjected to the air-blast was as follows : — 



Table I. 



1 mm. spark-gap with air-blast. 



Resonance frequency = N = 1*25 X 10 G . 



Oscillation 

 constant of 

 Cymometer 

 0= <SCL. 



Corresponding 



Frequency of 



Cymometer 



circuit =n. 



Cymo- 

 , meter 

 current 

 in amps. 



= a. 



Ratio 

 »/N. 



Corre- 

 sponding 

 actual fre- 

 quency 



//. 



Corresponding 



curreut from 



Eesonance 



Curve 



a. 



Ratio 



a/A. 



415 



l-205xl0' ; 



0046 



0-96 



1-2 X10 C 



0*041 amps. 



•343 



4-1 



1-22 „ 



0074 



0-97 



1-211 „ 



0-056 „ 



•469 



4-05 



1-235 „ 



010 



0-98 



1-224 „ 



0-0803 „ 



•672 



4025 



1-242 ., 



0113 



099 



1-238 „ 



0-106 „ 



•886 



4-000 



1-250 „ 



01195 



1-00 



1-250 „ 



0-1195 „ 



1-000 



3-975 



1-257 „ 



01146 



101 



1-262 „ 



0107 „ 



•895 



3-95 



1-264 „ 



0-1025 



1-02 



1-275 „ 



0-0865 „ 



•724 



3925 



1-272 „ 



0-086 



103 



1-281 „ 



00656 „ 



•549 



3-9 



1-282 ., 



0077 











3-85 



1-295 „ 



0-0558 











; 



