358 



Dr. L. T. More on the Changes in Length 



between the elongation and the intensity of magnetization 

 obtained as in the previous cases. The wire was then loaded 

 with a weight of 1750 kilog. per square centimetre and the 

 same relations found. The values are given in Tables III. 

 and IV. The effects of strains are also shown graphically by 

 nor 5 f or the observed and corrected value. On consult- 

 ing the figure, it is seen that straining the wire produces the 

 the same change that hardening it does. The values are 

 reduced, and the maximum points occur with less intense 

 magnetization. The curves in this figure, as well as in the 

 two former figures, marked no load, have an inaccuracy due 

 to the strain caused by the weight of the jacket cylinder, and 

 should have ordinates a trifle greater. 



Although the change in elasticity has hitherto produced 

 little effect, as soon as the wire is much strained this cor- 

 rection becomes very important and will modify the curves 

 materially. This alteration in the curves it has not been 

 possible to make, as the relation between the change in 

 elasticity and the intensity of magnetization is unknown. 

 However, from Bock's results some approximations may be 

 arrived at, and these will be considered when the errors likely 

 to occur in this investigation are discussed. 



Table III. 



H. 



I. 



B. 



f (ob,). 



^/B 2 \ 



— (corr.). 



69 



636 



8000 



+0-12 



-11-58 



4-1170 



11-4 



918 



11550 



0-62 



2414 



24-76 



185 



1080 



13600 



2-63 



33-46 



36-09 



24-2 



1109 



13960 



373 



35-27 



3900 



30-2 



1139 



14340 



3-87 



37-19 



41-06 



34-7 



1150 



14480 



3-48 



37-94 



41-42 



439 



1167 



14700 



2-42 



3909 



41-51 



55-8 



1184 



14930 



+ 1-20 



40-33 



41-53 



73-2 



1204 



15200 



-039 



41-79 



41-40 



81-8 



1212 



15300 



1-16 



42-35 



4119 



1000 



1223 



15470 



441 



4330 



38-89 



122-5 



1235 



15640 



910 



44-24 



35-14 



1481 



1247 



15820 



1413 



4527 



31-14 



1577 



1253 



15910 



1580 



45-80 



30 00 



1751 



1265 



16070 



18-58 



4671 



2813 



1921 



1276 



16230 



25-05 



47-65 



22-60 



228-6 



1287 



16400 



29-03 



48-65 



19-62 



251- i 



1293 



16500 



32-13 



49-26 



1713 



