lo Foster, Phenomena due to Repetitions of Stress. 

 Table II. 



Material. 



No. 



Stresses (tons per sq. in.) tension. 



Repetitions. 



Maxm. 



Minm. 



Mean. 



Range. 





[ 



i9"io 







9-55 





[34,500,000] 



Homogeneous 

 Iron 



I - 



33-4t 



M"3i 



23-86 



-19-10 



1,234,600 





V 



38-20 



19-10 



28-65 





475.500 





■1 



2865 

 57'3 





 28-65 



14-3 

 42-9 



28-65 



[36,500,000] 

 191,100 





( 



33'4 







i6-7 



-33'4 

 38-2 



300,000 (about) 



Krupp's 



Spring Steel, 



hardened. 



•1 



57"3 

 382 



57-3 



23-87 





 19-1 



40-6 

 19-1 

 38-2 



86,000 



339.T50 



35>6oo 





'1 



42-95 







21-5 



)42-95 



200,100 





57-3 



14-33 



35-8 



) 42-97 



22,900 





•1 



23-87 







II-9 - 



)23-87 



[40,600,000] 





( 



33 '4 1 



9-55 



2T-5 



)23-86 



701,800 







28-65 







14-3 



' 28-65 



468,000 



Krupp's 



- 



7 1 



33"4i 



4-77 



19-1 



28-64 



286,000 



Spring Steel 





38-20 



9*55 



23-9 



28-65 



176,300 



not hardened. 



V 



42-95 



14-33 



287 



28-62 



156,200 





( 



33'40 







16-7 



\ 33-40 



197,400 





1 



38-20 



4-77 



21-8 



•33"43 



99,700 





I 



42'95 



9'55 



26-2 



. 33-40 



81,200 



] signifies not broken. 



