﻿of Electrical Waves on Iron Wires. 



445 



I give the following example. The lengths of the oscilla- 

 tions are expressed in millimetres. 



Ikon. 



Copper. 



A. 



B. 



O. 



D. 



Length of 



oscillations on 



iron circuit. 



Length of 



oscillations on 



time circuit. 



Length of 

 oscillations on 

 copper circuit. 



Length of 

 oscillations on 

 time circuit. 



37 



608 



350 



614 



37 



608 



3-40 



6-00 



37 



5*90 



330 



600 



40 



6-10 



2-70 



5-26 



33 



516 



3-40 



610 



28 



360 



337 



636 







2-68 



3-72 



AVhen the ratios of A to B and of C to D are compared, it 

 will be seen that the time of electrical oscillations on an iron 

 circuit of the same geometrical form as a copper circuit is 

 longer than of those on the copper circuit. 



The rate of oscillation was not far from that which I 

 employed in my investigation on the damping effect of iron 

 wires. Since the inductance appears under the square root 

 in the formula t = 7r */LC, the changes in induction due to 

 the iron indicated by the above table may amount to from 

 five to ten per cent. 



Thus my results confirm those of Mr. Charles E. St. John, 

 who has shown by an entirely different method that the wave- 

 lengths sent out by a Hertzian vibrator on iron wires differ 

 in length from those transmitted on copper wires of the same 

 geometrical form as the iron wires. His results are of even 

 more importance in the theory of magnetism, for they deal 

 with more rapid electrical oscillations than those which I 

 employed. 

 Jefferson Physical Laboratory. 



