1894.1 and Steel and the Effict of Straining and Annealing. 185 



stress, there was a badly-marked yield point. The annealing may 

 have been imperfect. The yield point reappeared more characteris- 

 tically in succeeding tests after annealing. Excluding tests 2 and 3, 

 the position of the yield point is practically constant during five 

 loadings and annealings-. 



Experiment III. 



Mild Steel Bar, No. 1432. 



Original diameter = '749 in. Area = 0*4406 sq. in. Clips 8 in. apart. 



The bar was protected during annealing by placing it inside an 

 iron tube. The furnace containing the iron tube was first allowed 

 to get hot, the bar was then inserted, and when heated to a dull red 

 colour it was changed end for end, the gas was turned off, and the 

 bar allowed to cool in the furnace. 



The autograph diagrams are given in fig. 8. One-minute intervals 

 of time were marked on the diagram during the tests. The. yield 

 point in this case falls from 17'11 to 16'32 tons per sq. in. after eight 

 tests and annealings. The difference is not great. The total elonga- 

 tion of the bar was 3' 76 in. in eight tests. 



