526 Mr. Phillips on the Slow Stretch in Indtarubber, 



Load per sq. cm. -, 



in kilos. 



All up to 380 kilos. 



399-2 -000073 



458-0 -000174 



498*0 -000237 



531-0 -000297 



604-0 -000351 



700-0 -000428 



720-0 -000442 



795-0 -000542 



850-0 -000658 



At 900 the wire drew out so far that the scale 



went right out of view, and finally the 



wire broke. 



If we observed the form of the curve connecting h with the 

 load (Curve No. III. a) we see that there appears to be a 



1200 



1000 



800 



600 



it! 



Q 200 

































-l> 



























































































p/ 













u 



















S- 







®/ 



















































-c 























,/ 



















































x 



































































y 

















































































































very definite point below which there is no very considerable 

 slow creep, and there is a somewhat indefinite load above 

 which the wire begins to stretch very rapidly. The range 

 of load between these points is from 380 kilos, to 850 kilos, 

 per sq. cm. cross section. 



Exactly similar series of experiments have been conducted 

 with platinum, silver, and gold wires. All these substances 

 show the same general characteristics that between wide limits 

 (to nearly three times the smallest load necessary to produce 

 a creep) they stretch according to the law A'=a + 6 log t, and 



