SHUDDEMAGEN. — DEMAGNETIZING FACTORS FOR IRON RODS. 217 



The rod was carefully demagnetized and magnetized, apparently under 

 similar conditions each time. Parts of eight different magnetization 

 curves are shown in Figure 12 and illustrate the wide divergence at 

 the higher inductions. The reason for this peculiar behavior of the 

 fron was made clear when the rod was demagnetized and taken out of 



Figure 10. [Table V.] 



Reversal magnetization curves for a Bessemer soft steel rod of diameter 

 0.3969 cm. 



the solenoid, and then tested with a small pocket compass for con- 

 sequent poles. It was found that the rod was quite strongly magne- 

 tized, and had polarity in the order i\"-*S-X-AS', the two middle poles 

 being both near the middle of the rod. Evidently this rod had once 

 been lifted around a warehouse by means of an electric crane with an 

 electromagnet lifting device, so that it had been subjected to quite 



