﻿1054 Simple Model to illustrate Elastic Hysteresis. 

 involving formulae of the type 



The hysteresis was shown to be due, quite naturally, to 

 the I-Component. 



319 Dorset Avenue 1 am ' Gentlemen, 



OX«7 i/UISOL _T\_ V CHUG, -rj- 



Chevey Chase, Md.. U.S.A. Y ours etc -> 



September 23, 1922. A. PRESS. 



To the Editors of the Philosophical Magazine. 

 Gentlemen, — 



From the sketch given by Mr. Press, it is quite clear that 

 his model will produce effects analogous to those of the 

 model described in my paper (Phil. Mag. September 1922). 

 Until to-day, I had not seen the short abstract of Mr. Press's 

 paper in the July (1922) number of the ' Physical Review/ 

 I hope his full paper will be available before long. 



As evidence of the curious coincidence of the papers, I 

 note that Mr. Press's paper was read to the American 

 Physical Society on April 21st last. My own MS. was in 

 the hands of the publishers about April 5th last (the interval 

 between this date and publication I am not responsible for). 



Referring to my fig. 3, since the model is symmetrical 

 about OOi, only one-half of I he model need be considered in 

 actual practice. 



I should like to emphasize a result arising out of my 

 discussion, namely the fact that with either Mr. Press's or 

 my own suggested model, an alteration by overstrain of the 

 point of departure of the stress-strain curve in tension from 

 the straight-line law, is accompanied by an alteration of the 

 corresponding point of departure in compression. This 

 result, although of considerable technical importance, does 

 not appear to have received much theoretical attention. 



51 Chesterton Eoad, Yours etc., 



Cambridge. S. LEES. 



October 6th, 1922. 



