TABLES 252, 253. 

 DIELECTRIC STRENGTH. 



TABLE 252. Effect of Pressure of the Gas on the Dielectric Strength.* 



Length of spark is indicated by 7 in centimetres. The pressure is in centimetres of mercury at o C. 



TABLE 253. Dielectric Strength (or Difference of Potential per Centimetre of Spark Length) of Different 



Substances, in Kilo Volts, t 



SMITHSONIAN TABLES. 



* Paschen. 



t MacFarlane and Pierce, " Phys. Rev." vol. i, p. 165, 1893. 



245 



