Ductile Materials under Combined Stress. 89 



Table III. 

 Experiments to test Extensometer. 



Swedish Iron specimen, previously tested ; mean diam. 0'628 in. ; length 800 in 

 Extensometer- reading multiplied by O'OOOOO^GS = strain. 



1 





Extensometer-Readings 



. 





Load 



























in lbs. 



In- 



De- 



In- 



De- 



In- 



De- 





creasing. 



creasing. 



creasing. 



creasing. 



creasing. 



creasing. 



500 



043 



045 





265 





264 



1000 



086 



090 



086 



311 



307 





1500 



129 



133 





356 



350 



354 



2000 



172 



176 



171-5 



399 



393 





2500 



215 



220 





443 



437 



441 



3000 



258 



263 



258 



486 



480 





3500 



301 



305 





530 



523 



528 



4000 



344 



347 



344 



573 



566 





4500 



387 



390 





616 



610 



613 



5000 



430 



434 



430 



659 



654 





5500 



472 



475 





701 



696 



698 



6000 



515 



516 



515 



743 



738. 





6500 



558 







785 



781 





7000 







599 

 607 



826 







710 







617 &c 









In- 



De- 



In- 



De- 







1800 



creasing. 



creasing. 



creasing. 



creasing. 









-016 





1900 





-007-5 



-008 









2000 



dob 



000-5 



000 









2100 



008 



009 











2200 



016 













3500 





-043 











: 3750 





-021 



-022 









4000 





000 



-001 



-002 







4250 



... 





+021 



020 







4500 





... 



041 







S 



the grip 3, which is shown in fig. 7. These are so arranged 

 that the axis of the screws G, H, and the line st referred to 

 later, will bisect the angle between the planes A 1? A 3 and 

 A 3 , A 4 , and be perpendicular to their intersection. It is 

 evident that by this arrangement the lines GrH and st will 

 pass through the axis of the specimen (whatever be its size), 

 which is necessary for the determination of the mean ex- 

 tension should the specimen stretch unequally, owing to 

 bending-moment or other cause. At B is shown a hole, 



