OF ARTS AND SCIENCES. 123 



Large Iron Wire. Large Copper Wire. 



.20 17 



.20 18 



.19 .20 



I9 .18 



I wish to express my deep obligations to my assistant, Mr. W. C. 

 Sabine, for bis valuable suggestions and for his skill in the mechanical 

 details of this investigation. 



Conclusions. 



1. The magnetic permeability of iron wires exercises an important 

 influence upon the decay of electrical oscillations of high frequency. 

 This influence is so great that the oscillations may be reduced to a 

 half-oscillation on a circuit of suitable self-induction and capacity for 

 producing them. 



2. It is probable that the time of oscillation on iron wires may be 

 changed. Since we have been able to obtain only a half-oscillation 

 on iron wires, we have not been able to state this law definitely, 



3. Currents of high frequency, such as are produced in Leyden 

 jar discharges, therefore magnetize the iron. 



Jefferson Physical Laboratory, 

 Cambridge. 



