PEIECE. — ANOMALOUS MAGNETIZATION OF IRON AND STEEL. 639 



is almost parallel to the line KVAN which may be nearly straight. An 

 example will make this statement clearer. 



Table I. gives the material for a kind of hysteresis diagram for a cer- 

 tain round rod of hardened tool steel, 2.8 cm. in diameter, and 12 cm. 



Figure 2. Magnetic cycle for a piece of Seebohm and Dickstahl's special 

 magnet steel 12 centimeters long and 3.5 square centimeters in cross section. 

 If the exciting current be dropped from its highest strength to 0, and then re- 

 versed and given such a strength as to carry the magnetism to the negative 

 value represented by the point V, the residual magnetism will be shghtly 

 positive when the current is taken off. 



long, when magnetized in a certain long solenoid. The column headed 

 " H " gives the strengths in gausses which the fields within the solenoid 

 would have if the rod were not there ; the strengths of the exciting 

 fields in the rod would be very hard to determine even if they did not 

 vary firom point to point in the metal. The numbers under " N " are 

 proportional to the flux strengths through the central cross section of 

 the rod. 



If a positive current corresponding to H = 976 were sent through 

 the solenoid and were then stopped, a negative current corresponding 



