248 WHITEHEAD— HIGH VOLTAGE CORONA IN AIR. 



electrical engineering. It has not yet been determined definitely 

 that the law as proposed by Peek is the correct one. The results of 

 R. D. Mershon, one of the earliest observers and workers in this 

 field, on an experimental line at Niagara Falls, are distinctly at 

 variance with the results of Peek, as are those of Jakobsen on an 

 operating transmission line in Peru. On the other hand, the ob- 

 servations of Faccioli in Colorado, and Harding on an experimental 



60 80 100 120 140 160 

 Fig. 2. 



line at Purdue University, give results in good agreement with 

 Peek's formula. The difficulty appears to be that the formula does 

 not give correct values for voltages only slightly in excess of the 

 initial corona forming value, the explanation being that surface 

 irregularities and atmospheric deposits of various descriptions on 

 the surface of the wire result in partial corona formation at values 

 below those which would obtain for a perfectly round clean wire. 

 As the voltage is pushed above the corona forming value, these 

 initial losses become relatively small and the rising curve showing 

 the relation between loss and voltage gradually merges into the true 

 curve for a smooth wire. The law as announced by Peek is based 

 on the upper region of this curve. (See Fig. 2.) 



