Air -Blast upon the Spark Discharge of a Condenser. 687 



The values of the maximum cymometer current in amperes 

 without the resistance in its circuit ( = A) and with added 

 resistance ( = A x ), and the calculated values of the decrements 

 and spark-gap resistances are given in Table VI. 



Table VI. 

 1, 2, and 3 mm. spark-gaps without air-blast. 



Spark- 

 length 



Max. Cymo- 

 meter Current 



With resis- 

 tance added 



Primary 

 decrement 



Secondary 

 crement 



Spark re- 

 sistance 



m mm. 



in amperes 

 = A. 



=Ai. 



Sl 



0, 



in ohms. 



1 



•0952 



052 



•0423 



•019 



.75 



2 



•1202 



•067 



•0447 



•0198 



•81 



3 



•119 



•066 



•0383 



•0216 



•65 



If we collect together the same quantities for the spark- 

 gaps when blown on we have results as in Table VII. 



Table VII. 

 1, 2, and 3 mm. spark-gaps with air-blast. 



Spark- 

 length 

 in mm. 



Max. Cymo- 

 meter Current 

 =A. 



With resis- 

 tance added 

 =Ai. 



Primary 

 decrement 



Secondary 

 decrement 



Spark-re- 

 sistance 

 in ohms. 



i 



1 



2 



3 



•1195 



•101 



•1195 



•0635 



•046 



•0652 



•0467 

 •0443 

 •0397 



•017 

 •018 

 •0194 



•86 

 •80 

 •68 



It will be seen, therefore, that when the air-blast is not 

 applied the various values of D^ + So calculated from the 

 resonance curves are more irregular and deviate more from 

 the mean, this being the result of the difficulty of obtaining 

 correct galvanometer readings to delineate a good resonance 

 curve. 



The observations also appear to show that the air-blast has 

 not much influence upon the primary decrement or upon 

 the spark-resistance, or at most tends to slightly increase the 



