Tables 430, 431. 355 



DIELECTRIC STRENGTH. 



TABLE 430. — Dielectric Strengtb ol Materials. 

 Potential necessary for puncture expressed in kilovolts per centimeter thickness of the dielectric. 



TABLE 431. —Potentials In Volts to Frodnce a Spark In Kerosene. 



Determinations of the dielectric strenRth of the same substance by different observers do not agree well For a dis- 

 cussion of the sources of error see Mo^cicki, Electrotechn. Z. 25, 1904. 



For more detailed information on the dependence of the sparking distance in oils as a function of the nature of the 

 electrodes, see Edmondson, Phys. Review 6, p. 65, 1898. 



SMITHtONIAN TaBL' S. 



