THE THERMO-ELECTKIC EFFECTS OF LONGITUDINAL STRESS IN IKON. 57 



the only difference being that the former lies above, and the latter below 

 the respective branches of the main cyclic curve. The minor cycle 



(4 — 11 — 4) refers to the stage in which the minimum point has just 

 been passed. The "on" branch has apparently a point of inflexion, 

 and the "off" coincides with the corresponding portion of the main 

 cyclic curve. It is thus intermediate in form between the two preced- 

 ing minor cyclic curves, and reminds us of one of the forms through 

 which the main cyclic curve was evolved, as explained in § 8 (See 

 Fig. 3 and 4, PI. I). 



§ 11. These experiments suggest that in the thermo-electric 

 curve the effect of the hysteresis is more conspicuous in the region 

 between the axis of zero load and the minimum points, than in the 

 region beyond them. In the latter, the iron seems to have been 

 brought into a stable condition, inasmuch as when tension is applied 



