444 



Dr. J. Hopkinson. 

 FIG. 2. 



[Nov. 20, 



occur, not only at the same temperature, but simultaneously. A con- 

 siderable magnetising force, 6'56, was taken, as it was expected and 

 found that the magnetic property would then be more apparent when 

 it was in the intermediate condition between the two temperatures of 

 recalescence. 



In fig. 3 are the results of a ring containing 0'9 per cent, of carbon. 

 In this case we have a curve of heating and of cooling with magnetic 

 property for comparison, and also a second cooling curve to show the 

 recalescence temperature when the heating had been higher. Unfor- 

 tunately I had forgotten to record the magnetising force ; it was, 

 however, much less than in the last case, probably less than unity. 

 Looking at the curve, we see that there is a slight absorption of heat 

 at time 11 h. 17 m., temperature 710 C. with doubtful effect on the 

 magnetism. At time 11 h. 27 m., temperature 770 C., powerful absorp- 

 tion of heat begins and continues to time 11 h. 55 m., temperature 

 808 C. ; it is between these times that the magnetisability is de- 



