44i 



Tables 51 7 and 51 8 

 DIELECTRIC STRENGTH 



TABLE 517.— Dielectric Strength oi Materials 



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



TABLE 518.— Potentials in Volts to Produce a Spark in Kerosene 



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

 cussion of the sources of error see Mos"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. 



Smithsonian Tables 



