182 DE. S. W. J. SMITH AND ME. J. GUILD: A THEEMOMAG-NETIC STUDY OF 



Here the heating was interrupted (twice) before the "solution" of the eutectoid 

 was complete. Cooling was continued until most of the eutectoid had reappeared ; 

 but heating was begun again while some dissolved eutectoid still remained. Now, the 



675 



775' 



loss of magnetism took place, slowly at first and then rapidly, all at a temperature 

 below that at which it began when none of the transformed material was present. 



If the true equilibrium temperature be that at which iron, carbide of iron, and 

 solid solution of eutectoid composition can coexist for an indefinite time in the steel 

 without change, it follows from what precedes that this temperature is below 735 C. 



