TABLE 287. 



PERMEABILITY OF SOME OF THE SPECIMENS IN TABLE 286. 



This table gives the induction and the permeability for different values of the magnetizing force of some of the speei- 

 mens in Table 286. The specimen numbers refer to the same table. The numbers in this table have been taken 

 from the curves given by Dr. Hopkinson, and may therefore be slightly in error; they are the mean values for 

 rising and falling magnetizations. 



TABLE 288. 



MAGNETIC PROPERTIES OF SOFT IRON AT O 



AND 1OO C. 



TABLES 289. 



MAGNETIC PROPERTIES OF STEEL AT O c 



AND 100 C. 



* "Phil. Mag." 5 series, vol. xxix. 



t The results in this and the other tables for forces above 1200 were not obtained from the ovoids above referred 

 to, but from a small piece of the metal provided with a polished mirror surface and placed, with its polished face nor- 

 mal to the lines of force, between the poles of a powerful electromagnet. The induction was then inferred from 

 the rotation of the plane of a polarized ray of red light reflected normally from the surface. (See Kerr's " Constants,'' 

 P- 292-) 



278 



