

THE 



AMERICAN JOURNAL OF SCIENCE 



[THIRD SERIES.] 



I 



\ 



Art. I. — On the Alternating Electric Arc between a Ball 

 and Point ; by Edward L. Nichols. 



[Contributions from the Physical Laboratory of Cornell University, No. L] 



Part I. 



(From Experiments made by Messrs. W. K. Archbold, and G. L. Teeple.) 



The phenomenon which forms the subject of this paper, 

 was first brought to my notice by Mr. E. G-. Acheson, the 

 result of whose unpublished observation, may be briefly stated 

 as follows : 



Two wires, which formed the terminals of the secondary 

 coil of an alternating- current transformer, were brought nearly 

 into contact. One wire was armed with a ball, the other with 

 a point. When the distance was such as to admit of a discharge 

 between the two, it was found that a galvanometer in shunt 

 around the ball and point, indicated a considerable flow of con- 

 tinuous current. 



This phenomenon has recently been subjected to investiga- 

 tion by Messrs. Archbold and Teeple. Their experiments, 

 from which in great measure, the data used in the first part 

 of this paper have been taken, are described at length in their 

 Thesis in Electrical Engineering, -which is now in the library 

 of Cornell University.* 



The apparatus used in the verification of Mr. Acheson's obser- 

 vation, consisted of a Ruhmkorff coil of moderate size, the 



* The Effect of placing a Ball and Point in a High Potential Alternating Cur- 

 rent Circuit, by W. K. Archbold and G-. L. Teeple. Thesis in MS., Cornell Uni- 

 versity Library ; 1889. 



Am. Jotjh. Sci. — Third Series, Yol. XLI, No. 241. — January, 1891. 

 1 



