14 



ART. 9. — S. KUSAKABE. 



As the hysteresis curve becomes more and more vertical 

 when the amplitude of the cycle increases further and further, 

 the mean elasticity necessarily weakens when the amplitude of 

 the strain increases. For instance, in a case of sandstone where 

 the curves conld all be represented by a series of parabolic ex- 

 pressions, the constant term of them was : — 



TABLE V. 



Thus it is important to notice how the modulus of elasticity di- 

 minishes when the amplitude of the strain increases. 



Here it will suffice to remark that, as in the case of the 

 modulus of rigidity, the modulus of elasticity also is comparatively 

 greater in a strained than in the neutral state. 



