408 Messrs. Kei Iokibe and Sukeaki Sakair Effect of 



difference of rigidity is probably due to the effect of cold 

 drawing, but not to the impurities entering the copper wire. 

 Benton * also suggests in his memoir that the annealing of 

 metals causes a diminution o£ rigidity. 



The results of experiments for logarithmic decrement are 

 also graphically given in fig. 2, the curve being that for 

 the electrolytic copper. From room temperature to 170° 

 increase of logarithmic decrement is very slow, and increases 



Fig. 2.— Copper. Fig. 3.— Zinc. Fig. 4.— Aluminium. 



IOO 200 300 



xxicr 



IOO 



n; 

 ao 3-2 



€0 2-8 



4-0 2-4 



20 2-0 



O I 





■ 







:!0"" 





! / 







/* 



^u« 











l\ 



O IOO ZOO 300 400 



Fig. 5.— Gold. 

 n : rigidity. 



OQ IOO Zo6 4O0 



Fig. 6. — Silver. 

 X : log. dec. 



afterwards very rapidly. The course of the curve is exactly 

 the same as that by Horton. Since the absolute value of 

 the logarithmic decrement of a metallic wire varies greatly 

 with the previous history and the conditions under which 



* Benton, Phvs. Rev. he. cit. 



