318 



Scientific Proceedings, Royal Dublin Society. 



Tablk IY. 



The results are arranged under the dimension ratios 27 and 33 

 respectively, and for the purpose of contrast a magnet S.C.I., made of 

 practically pure iron, is placed at the head of each group. Comparing 

 Nos. 3 and 4, which have the same quantity of manganese, the one per cent, 

 of nickel in No. 4 does not seem to have much effect on the moment, as the 

 reduction of the magnetic moment by nearly 9 per cent, can be accounted for 

 by the difference of 0'25 per cent, of carbon in No. 4 ; the nickel, however, 

 may account for the decrease of nearly 50 per cent, in the retentivity. 



In Nos. 7 and 8 the small percentage of nickel has increased the magnetic 

 moment by nearly 6 per cent, and improved the retentivity some 48 per 

 cent. ; the other chemical constituents being approximately the same, a small 

 percentage of nickel does improve the retentivity.^ 



In the tungsten steels, Nos. 9 and 10, the 0'5 per cent of carbon, and the 



1 The eliemical analyses of the specimens were made in the chemical lahoratory of the Hecla Steel 

 Works, Sheffield, the amount of iron hi-ing estimiited by difference. 



- Scient. Trans. Roy. Dublin Soc, vol. vii., Plate iv., Jan. 1900, p. 67. 



