the Cathode in the Electric Discharge in Air. 611 



Table III. — Aluminium wire, 2*08 mms. in diameter. 



023 



p- 



'• 



C. 



C 



6-7 



1-5 



5-8 



0-58 



3-64 



5-3 

 1-3 



7-49 

 2-16 



0-39 

 0-46 



313 



6-3 



6-96 



0-35 



2-37 



8-13 



2-6 



2-2 



1305 



5-78 



2-26 



1-97 



11-95 



0-30 

 0-37 



0-38 

 0-39 



207 

 >> 

 » 



7-4 



3-3 



10-8 



596 

 2-49 

 9-7 



0-39 

 0-37 

 0-43 



1-46 



12-25 



5-46 



0-31 



1-16 



>> 



7-5 

 12-25 



2-30 

 4-09 



0-27 

 0-29 



113 



7-95 



2-35 



0-26 



0-975 



11-4 



4-8 



3-23 



1-18 



0-29 

 0-25 



0-78 



3-1 



8-8 



12-3 



0-60 

 1-63 

 2-43 



025 

 0-24 

 0-25 



0-68 



12-9 



235 



0-27 



053 



6-1 

 12-2 



0-68 

 1-75 



0-21 

 0-27 



0-45 



)5 



9-2 

 130 



5-7 



1-13 

 1-79 

 0-63 



0-27 

 0-31 

 0-25 



0-45 



Mean 0323 



n 



Table V. contains the values of for each of the wires 



used. l l md 



The current-density for the two thickest wires is nearly the 

 same, but for the smaller wires it is much greater. This 

 suggests that the effective diameters o£ the wires are really 

 greater than their actual diameters, so that if, in calculating 

 the current-density, a small constant quantity was added to 

 the diameter of each wire, then the current-density would 

 be the same in every case. It was found by trial that if 

 0*5 mm. is added to the diameters the calculated current- 



