Tables 426. 427. 353 



DIELECTRIC STRENGTH. 

 TABLE 426< — Stead? Potential Difference In Volts required to produce a Spark In Air with Ball Electrodes. 



Based on the results of Bailie, Bichat-Blondot, Freyburg, Liebig, Macfarlane, Orgler, Paschen, Quincke, de la Rue, 

 Wolff. For spark lenglhs from i to 200 wave-lengths of sodium light, see Earhart, Phys. Rev. 15, p. 163 ; Hobbs, 

 Phil. Mag. 10, p. 607, 1905. 



TABLE 427. —Alternating Current Potentials required to produce a Spark In Air with various Ball Elec- 

 trodes. 



The potentials given are the maxima of the alternating waves used. Frequency, 2Z cycles per 



second. 



Spark length, 

 cm. 



0.08 

 .10 



•15 



.20 



•25 

 0.30 



•35 

 .40 



45 

 •50 



0.6 



•7 



.8 

 0.9 

 1.0 



1.2 



1.4 

 1.6 



1.8 

 2.0 



/? = I cm. 



3770 

 4400 

 5990 

 7510 

 9045 



10480 

 1 1980 

 13360 

 14770 

 1614O 



18700 

 21350 

 23820 

 26190 

 28380 



32400 



35850 

 38750 

 40900 



42950 



/f=i.g2 



4380 

 5940 

 7440 

 8970 



10400 

 11890 

 13300 

 14700 

 16070 



18730 

 21380 

 24070 

 26640 

 29170 



34100 

 38850 

 43400 



y? = s 



4330 

 5830 

 7340 



10270 

 1 1670 

 13100 

 14400 

 15890 



18550 

 21140 

 23740 

 26400 

 28950 



33790 

 38850 

 43570 

 48300 



y? = 7.S 



4290 



5790 

 7250 

 8710 



10130 

 11570 

 12930 

 14290 

 15640 



18300 

 20980 

 23490 

 26130 

 28770 



33660 



38580 

 43250 

 47900 

 52400 



4245 

 5800 

 7320 

 8760 



10180 

 II61O 

 12980 



14330 

 15690 



18350 

 20990 

 23540 

 26110 

 28680 



33640 

 38620 

 43520 



R = iS 



4230 

 5780 

 7330 

 8760 



XOI50 

 II59O 

 12970 

 14320 

 15690 



18400 

 21000 



23550 

 26090 

 28610 



33620 

 ^580 



Based upon the results of Kawalski, Phil. Mag. 18, p. 699, 1909. 



Smithsonian Tables. 



