MAGNETISM AND TWIST IN IRON AND NICKEL. 



519 



Table VI. — continued. 



Diameter of Wire 

 in mm. 



Current in Amperes. 



Half-Twist in 

 Degrees. 



Lag Area 



5T. 



Range of Intensity. 



0-87 



1-99 



100° 



- 4-5 



531 





)> 



)> 



- 77-2* 



532* 





2-52 



)> 



- 5-7 



543 





0-27 



110 



+ 19-4 



469 





»> 



>> 



- 81-3* 



473* 





0-47 



>) 



+ 26-2 



458 





0-87 



)> 



+ 8-6 



499 





1-18 



)) 



- 1-2 



517 





1-88 



)) 



- 15-2 



540 





2-47 



)> 



- 25-9 



556 





;> 



» 



- 143-8* 



540* 





0-48 



135 



- 33-3 



510 





0-84 



»> 



- 68-3 



534 





1-51 



>> 



- 91-3 



552 





>> 



j» 



-217-8* 



528* 



2-0 



0-15 



45 



- 0-2 



3-6 





0-25 



)» 



- 0-9 



11-5 





0-47 



j» 



- 0-5 



29-5 





0-68 



)> 



- 1-8 



44-5 





1-05 



>> 



- 2-1 



74 





1-62 



» 



- 2-3 



149 





2-12 



)> 



- 0-4 



187 





3-69 



)> 



- 2-4 



285 





0-27 



90 



- 6-4 



43 





0-59 



>> 



- 12-8 



92 





1-12 



)> 



- 17-9 



184 





1-85 



>> 



- 4-6 



197 





3-47 



>» 



+ 9-4 



258 





335 



>) 



+ 19-0* 



326* 





0-30 



135 



- 16 



40 





0-66 



)> 



- 23 



66 





1-46 



» 



- 39 



122 





2-16 



j) 



- 45 



207 





3-40 



M 



- 55 



275 





3-27 



>> 



- 97* 



316* 



It will be seen on inspection that two of these wires, the first and second namely, 

 behave very similarly to the first one. For small twists and small currents the magnetic 

 lagging is positive, but changes to negative for higher twists and stronger currents. To 

 bring out the general characteristics we may construct for these two wires the following 

 short tables, and compare them with the similarly constructed table of the preceding 

 paragraph. The first three rows are for the wire of diameter 1 '3 mm. ; the last four for 

 the wire of diameter 0'87 mm. It should perhaps be mentioned that the wires of Table 

 VI. were obtained three years ago from the same manufacturer, whereas the wire of Table 

 V. belongs to a piece I have had for eight years in my possession, and is probably not so 

 pure a specimen as the others. 



Here the same tendency to the vanishing away of the positive lagging, under the 

 influence of strong currents and large twistings, is clearly shown. 



The results for the nickel wire of 2 mm. diameter are, so far as regards the lagging 



