6 



Peirce — Magnetic Properties at High Excitations. 



and carried a heavy current. Although the cardboard was not 

 favorably placed, there are evidences that at least ten con- 

 sequent poles were created between the ends of the core when 

 it was strongly excited. When the exciting current was 

 reversed these poles changed sign, but in many places outside 

 the exciting coil the direction of the Held was always opposed 

 to what it would be if these consequent poles did not exist. 

 This core has been annealed as well as the maker could do 



Fig. 4. 





'"'■.■;- '■■■;:■':- 



it, after it had been bent into shape, but the process demands 

 great skill and, as is well known, soft Norway iron is very likely 

 to acquire slight differences of temper due to unequal heating 

 in the forge lire. 



Table II exhibits the results of some observations made 

 upon a half-inch rod of Norway iron (R), when magnetized 

 in a uniformly wound solenoid. The rod was about ten feet 



