Tables 252, 253. 

 DIELECTRIC STRENGTH. 



TABLE 252. — EUect of Prossuio ol tho Qas on the Dlolectrlo Strongth.* 



Length of spark is indicated by /in centimetres. The pressure is in centimetre* of mercury at n' C. 



TABLE 253 -Dielectric Strength (or DlHerence ol Potential per Centimetre ol Spark Length) of Dllferent 

 * . Substances, In Kilo Volts, t 



Substance. 



Air (thickness 5 mm.) 

 Carbon dioxide " 

 Coal gas " 



Hydrogen " 



Oxygen " 



fll — 



23.8 



22.7 



15.1 

 22.3 



Substance. 



Beeswaxed paper 

 Paraffined paper 

 Paraffin (solid) . 



u ^ 



■c-s 



Q " 



540. 

 360. 

 130. 



Substance. 



Kerosene oil . . 

 Oil of turpentine 

 Olive oil ... 

 Paraffin oil . . 

 Paraffin (melted) 



Smithsonian Tables. 



• Paschen* 



t MacFarlane and Pierce, " Phys. Rev." vol. i, p. 165, 18.53- 



245 



■Si 



50- 



f^. 

 87. 

 56. 



