ON STRESS DISTRIBUTIONS IN ENGINEERING MATERIALS. 283 



Table III. 



(?) See footnote Table II. 



is about ten times greater than that of carbon, and that therefore analyses 

 which omit this constituent are valueless for comparisons lilce the present. 



Tables II. and III. deal with elastic and plastic limits on the above 

 lines, but as these limits are badly defined it has seemed desirable to 

 record not only the first indications of curvature in the elastic lines, viz. 

 T,., C,., and S,. for tension, compression and shear, but also those stresses 

 T,., C,., and S,, when the strain-indicator pointers commenced to creep 

 after the additions of small loads. Under the tension and shearing stresses 

 the material seemed to break down at certain badly defined stresses, 

 which might be called plastic limits T^, and S^,, and sometimes this break- 

 down resulted in what is generally known as ' drop ' T,, and S,,, the steel- 

 yard dropping without additional loading. Both S,, and S^ have been 

 estimated from the torsion tests as explained in the note at the end of the 

 paper. 



As will be seen from Table III. the several ratios vary within the 

 following limits : — - 



It will be seen that only the last two ratios, and especially the last 

 one, are at all steady. The conclusion may therefore be drawn that 



