Discharge of Electricity from Points. 243 



observed values for a number of points and pressures. In 

 the first of the tables the experimental values are the means 

 of the results given in Table I. In the second table are 

 given a few of Zeleny's results for small wires. 



Table II. 

 Comparison of Calculated Results and Experimental. 

 Sparking potentials in kilovolts. 



ap. 



d 



- =10. 



a 



d 



-=20. 



a 



*=30. 

 a 





Experimental. 

 + - 



Calc. 



Experimental. 



+ - 



Calc. 



Experimental. 

 + 



Calc. 



2-5 



1-22 



107 



123 



1-33 



1-22 



143 



1-41 



1-29 



155 



, 5-0 



1-66 



1-63 



1-81 



1-79 



1-77 



2-10 



1-90 



1-83 



2-27 1 



10-0 



237 



2-46 



2-69 



265 



274 



311 



2-82 



2-94 



3-37 i 



: 200 



370 



3-87 



4-06 



4-10 



4-35 



4-69 



4-38 



4-63 



5-07 ! 



30-0 



4-73 



5-21 



5-47 



526 



5-74 



Cr 33 



5'53 



i 



610 



6-85 



Experimental Results taken from paper by J. Zelenv. 

 Phys. Rev. xxv. p. 317 (1907). 



j 



a. 



c/=l-5. 



d=\. 



Experimental. 



+ 



Calc. j 



Experimental. 

 + - 



Calc. 



•00244 



1-600 



1-125 



1-52 









0039 



2-00 



1-475 



1-81 



1-895 



1-465 



1-81 



•0091 



2-45 



1-975 



266 



2-30 



1-85 



2-51 



The pressure was atmospheric. 



The value of the electric force X x at the vertex of the 

 point has been shown above to be given by 



IS 



Xx = 30H -- for atmospheric pressure. 



\a 



For very small values of a this tends to 



JL8 



or X x \/a = l8. 



112 



X 1 = 



