Annealing on the Magnetic Moments of Steel Magnets. 429 



ture has diminished the magnetic moment per gramme by 

 13 per cent, in specimen II., and by about 12 per cent, in 

 III., whilst in specimen I. it is decreased by nearly 4 percent. 

 We also find that the total percentage loss due to falling four 

 times through a height of 1*5 metre has increased above the 

 results of the last experiment as much as 100 per cent, in 

 specimen II., and 70 per cent, in I., and 40 per cent, in the 

 case of specimen III. 



The magnets were not again magnetized, but were allowed 

 to lie undisturbed in the varying temperature of the room for 

 a period of nine months, that is from May 15, 1886, till 

 February 12, 1887. This was done merely to see what would 

 be the effect of time upon them in their annealed condition. 

 They were put through a similar series of observations, with 

 the exception that they were not remagnetized. The follow- 

 ing Table contains the results : — 



Table VIII. 



Magnets not remagnetized and left undisturbed for 9 months. 



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 



47-79 

 49-48 

 48-51 

 50-70 

 4801 



1-02 

 0-50 

 1-50 

 0-96 

 1-01 



1-03 



0-50 

 0-00 

 1-45 



o-oo 



204 

 0-98 

 1-50 

 2-40 

 1-01 



Mean 



48-89 



1-00 



0-59 



1-58 



Specimen II. 



1 



2 



3 



4 



5 



41-47 

 43-02 



39-28 

 41-00 

 38-66 



2-25 

 2-89 

 1-58 

 1-14 

 0-80 



4-23 

 1-50 

 0-80 



o-oo 



2-52 



5-64 

 4-34 

 2-38 

 1-14 

 3-22 



Mean 



40-68 



1-73 



1-81 



3-34 



