591.] Power given by any Electric Current to any Circuit. 431 



Table II. 



The experiments already described tell us that a hissing arc may 

 cause a considerable phase difference between the P.D. and the 

 current, but they do not enable us to decide whether such an arc 

 causes the current to lag behind the P.D., or to lead in front of it. To 

 decide this point, that is, to decide whether a hissing arc acts like an 

 inductive coil, or a condenser, a variety of experiments were made by 

 tting induction or capacity in series with the arc. The following 

 ves the result of one such experiment : In series with a hand- 

 regulated lamp (and, therefore, containing ho electromagnet), was 

 placed a condenser of 89 microfarads (fig. 4). Uncored carbons 

 were used, and they were adjusted so that the arc was very short at 

 first ; the carbons were then not touched, and, as they burnt away, 

 the arc grew longer and longer until it finally went out. The fre- 

 uency was maintained at 200 periods per second. 



FIG. 4. 



