564 



Messrs. K. Honda and $. Sliimizu 



In Swedish iron and tungsten-steel, cooling by liquid air 

 decreases the elongation of the metals ; the change in tung- 

 sten-steel is very small, but in Swedish iron it is relatively 

 large. In nickel, the contraction is diminished by cooling to 

 a field of 670 C.G.S.; but it is increased in stronger fields. 

 In cast cobalt, the contraction is considerably increased, 

 except in weak fields, where a slight decrease of contraction 

 is observed. In annealed cobalt, the contrary is the case ; 

 the contraction is always diminished. 



With tungsten-steel and nickel, the magnetic changes of 

 length before and after the cooling coincide with each other. 

 But in Swedish iron, the elongation after cooling becomes 

 greater than that before cooling. In cast cobalt, the mag- 

 netic contraction after cooling slightly decreases, as compared 

 with the elongation before cooling; but with annealed cobalt, 

 the contrary is the case, except in weak fields. 



The above results for Swedish iron, nickel, and annealed 

 cobalt agree with those obtained by us * with rods of these 

 metals. The change of elongation of tungsten-steel in high 

 fields does not coincide with that found in our former ex- 

 periments. But the change being very small, the discrepancy 

 may be accounted for by taking into consideration the de- 

 magnetizing force, with which onr former experiments were 

 not concerned. 



( f ) Length Change of JYickel- Steels. 



The observed changes of length are given in Table VI. and 

 in figs. 4 a, b, c, d, e,f, <7, h, i (PI. X.). 



Table VI. 

 Nickel-Steel 70*32 per cent. 



t=2i 



i°-oc. 



*=_186°C. 



t=2i 



°-5 0. 





SI 





SI 





SI 



H. 



r xio«. 



H. 



T x.W. 



H. 



I >< 106 - 



3-0 



0-6 



30 



0-7 



2-9- 



0-9 



8-3 



3-2 



19-0 



52 



20-2 



5-3 



211 



61 



32-8 



8-6 



67 9 



104 



45-9 



92 



85'3 



111 



121-2 



11-6 



109-4 



11-2 



106-8 



121 



280-1 



11-9 



232-6 



11-7 



228-7 



12-8 



422 



120 



392 



11-8 



334 



12 9 



499 



120 



546 



11-9 



473 



13 



639 



11-9 



663 



11-7 



631 



12-9 



802 



11-9 



791 



11-6 



763 



12-6 







* K. Honda and S. Shimizu, he. cit. 



