MAGNETISM AND TWIST IN IRON AND NICKEL. 



501 



Table IV. — (c) For Nickel. Line Current = 2 '8 5 — continued. 



Field. 



Twist. 



Field. 



Twist. 





-73-2 



+ 20-5 



? 







-67-9 



20-7 





-676 



4-21-5 



1 -64-4 



21-5 





-62-3 



22-2 



-47-0 



22-0 



-45-6 



23-7 



-35-3 



22-1 



-35-3 



23-5 



-25-9 



21-3 



-25-9 



21-8 



-11-8 



17-1 



-11-8 



+ 8-4 







+ 8-5 







-10-1 



+ 10-9 



-14-0 



+ 8-8 



-17-8 



24-1 



-21-5 



24-1 



-20-8 



33-8 



-23-0 



33-8 



-215 



44-7 



-23-0 



44-7 



-21-8 



52-3 



-22-5 



52-9 



-21-4 



61-7 



-21-3 



+ 62-6 



-20-8 



+ 67-0 



-20-7 





... 





-> 









(cl) For Nickel 



Field =56'6. 





Current. 



Twist. 



Current. 



Twist. 





-2-70 



+ 17-9 



t -2-57 



+ 16-7 





-216 



15-8 





-2-13 



134 



* -1-56 



133 





-1-54 



8-7 



-I'll 



11-0 



-1-09 



4-8 



-0-79 



9-3 



-0-78 



+ 2-1 



-0-47 



7-3 



-0-45 



- 0-4 







4-1 







- 4-1 



+ 0-46 



+ 0-5 



+ 0-45 



- 6-2 



076 



- 2-2 



0-78 



- 9-2 



1-08 



- 5-0 



110 



-10-9 



1-50 



- 9-2 



1-55 



-13-2 



2-06 



-13-9 



+ 2-11 



-15-6 



+ 2-53 



-17-4 









~" 





The first two cycles (a and b) were made with the same iron wire as was used in the 

 experiments of Table I., and were made at the same time as these, in the spring of 1887. 

 The third and fourth cycles, however, are for a nickel wire, 27 cm. long. 



It was wholly enclosed in one of the magnetising coils (already described) set 

 vertically, so that the wire hung free in the earth's vertical field when no current was 

 circulating in the coil. These two experiments were made in the spring of 1890, and 

 belong to a series of experiments carried out for a different object. The twists are, as 

 formerly, the total twists in the length of wire used. 



The two cycles for the iron differ chiefly in the range of field used. In cycle (a) the 

 range is from nearly + 200 to —200, so that the field for the maximum twist is far 

 exceeded. In cycle (b), on the other hand, the field is carried just so far as to bring 

 the twist to near its maximum, that is, to about ±13. These cases are represented 

 graphically in fig. 1, Plate III., the dotted curve referring to the smaller field range. 



VOL. XXXVI. PART II. (NO. 18). 4 F 



