Annealing on the Magnetic Moments of Steel Magnets. 425 



magnetic moment of specimen I. and lowered it in III., 

 whilst that of II. remains unaltered. Also that the total 

 percentage loss in I. and II. is increased, whilst in III. it is 

 slightly diminished ; indeed, we find it is doubled in speci- 

 men I., and in II. it is increased 17 per cent., whilst it is 

 diminished 12 per cent, in specimen III. 



We must remember, however, that specimen I. alone con- 

 tains sulphur, and has the least quantity of manganese, and by 

 far the most silicon of the three, while II. contains the least 

 amount of silicon. 



The same fifteen magnets were again annealed for a period 

 of two hours in the same oil-bath at a temperature of 100° 0. 

 They were allowed to cool and lie for six hours, as formerly, 

 at the ordinary temperature of the room. They were also 

 magnetized and treated similarly in every way as in previous 

 experiments. Then, after lying aside undisturbed for a period 

 of twenty hours, they were put through the same series 

 of observations for determining the loss in their magnetic 

 moments. The results are given in the following Table: — 



Table V. 

 (Annealed for two hours at 100° C.) 



Specimen I. 



Number of 

 magnet. 



Magnetic 

 moment, 

 per gram. 



Percentage loss due to 

 falling 



Total loss. 



one time. 



three times. 



1 



2 



3 



4 



5 



6209 

 60-72 

 60-72 

 62-40 

 61-20 



1-56 



1-99 

 1-99 

 1-94 

 2-37 



1-19 

 1-02 

 061 

 0-39 

 1-21 



2-73 

 2-99 

 2-59 

 2-32 

 2-56 



Mean 



61-42 



1-99 



1-08 



2-84 



Specimen II. 



1 



o 



3 



4 



5 



72-72 

 72-72 

 72-10 

 73-00 

 72-46 



2-13 



2-97 

 2-57 

 2-96 

 3-42 



1-70 



0-88 

 1-31 



0-87 

 0-88 



3-83 



3-83 

 3-86 

 3-81 



4-27 



Mean 



72-60 



2-81 



113 



3-92 



