J94 



BECKER AND DAY 



TABLE. 



Photograph 



No. 



Length, j Width, 

 y. X. 



Poisson's Ratio. 



o- = . soon- 



er' = a" + 



Compression, 



Compression. 



Compression. 



Tension. 



The values of Poisson's ratio are computed from the 3 equations, 



logy-logy^ 



a = 



* oc^ ^Ay 



.'- = 2^ f, _ J ^ \. 



The equation for ct results from the assumption that the loadstrain relation is an 

 exponential.' a' is the ratio of the observed lateral contraction to the linear 

 elongation expressed in terms of the initial dimensions ; and c^' is the same 

 ratio, the lateral contraction being computed on the assumption that the volume 

 remains constant.^ 



' Amer. Journ. Sci,,Nov., 1S93, p. 34S. 



^ Stewart iS: Gee, General Physics, p. 194. 



