Variation of the Rigidity oj Phosphor-Bronze. 421 



Ylcr. 2. 



>- 



Q 



O 



or 



CO 



o 







V 



o 



L A 



25 



D S 



* 



(I.) Behaviour of strip on first test. 

 (II.) „ ,, two days later. 



(III.) ,, ,, fortnight later. 



t (IV.) „ ,, after overstraining it by bending. 



(V.) „ ,, after annealing it. 



* Curve I. became level for heavier loads than those shown in diagram* 

 and the maximum value obtained was much less than those in curve V. 



t This was tested a month later and to a close approximation ^the- 

 same values were obtained. 



Influence of the Thickness of the Strip. 



When thicker strips than these were tried variations in the 

 coefficients of torsion were observed, but these were not more 

 than 5 per cent., and were very irregular, the irregularities 

 being much greater for small loads than for large ones. 



