Lifting Power of the Electro-Magnet. 



52:) 



Table XXXIII. 



•which give — 



L = 104-30 \l + txL-' (708061) - f x Z"' (5-14056) + fx Z"' (2-95041) j. 



The contrast between this result and the two preceding is great. With 

 the iron magnet the change produced by the extreme range of temperature is 

 a decrease from 214 to 205. When three-sevenths of the circuit are iron, and 

 the rest steel, it is an increase from 135 to 138; and when all is steel, from 

 102 to 113. The diiference is more evident on computing the proportional 

 change from 60° to 190°. It is for— 



Iron - 0-02886. 



Compound -1- 0-02849. 

 Steel -1- 0-11892. 



In the two last, the parts subject to direct excitation are the same; in the 

 two first they differ ; on the other hand, the last differ in the parts which act 

 solely by induction, while the first agree. Hence it seems probable that both 

 in direct and inductive magnetization, the action of heat on steel is the reverse 

 of iron. 



A series for various values of yfr is given in — 



VOL. XXIII. 3 z 



