ON THE ENDURANCE OF METALS. 



431 



Table VII. — Bar subjected to Alternating Tension and Govipression. 

 (Tons per Square Inch.) 



Time between the Loadings 



Wrought-iron bar — 



1 . Original condition 



2. 6 days . 



3. 1 hour . 



4. 5 minutes 



5. 20 hours 



6. 1 hour . 



7. 46 minutes 



8. 30^ hours 



9. \^ „ 



10. 2 



11. 9 minutes 



12. 27 hours 



13. 30 minutes 



14. 3 days . 



15. 2 „ . 



16. 2 „ . 



17. 5 hours 



18. Next day 



19. 2 days . 



20. 2^ hours 



21. 4^ „ . 



22. 1 day . 



23. 9 hours 



Bessemer Steel Bar — 



1. Original condition 



2. 23 hours 



3. 5 „ . 



4. 4 days . 

 0. 2 „ . 



6. 5^ hours 



7. 21i „ 



8. 2 days . 



9. 4 hours 



10. 2i „ 



11. 16 „ 



12. 23 „ 



Elastic Limit 



13-7 



4-8 



6-35 

 715 



8-75 



17-7 

 16 

 5-55 

 8-85 



10-5 

 9-65 



Com- 

 pression 



4-8 

 9-65 

 12-9 



Load imposed 



Tension 



12-7 

 4-8 

 715 



7-95 

 7-95 



3-24 

 4-85 



8-85 



9-65 

 9-65 



13-7 

 14-5 



14-5 



6-45 

 7-25 

 7-25 



635 

 7-15 



7-95 



24-0 

 24-0 

 8-5 

 9-7 

 11-3 

 11-3 



Com- 

 pression 



14-5 

 14-5 

 14-5 



14-5 

 6'45 



17-3 

 17-5 



6-35 



7-15 



715 



8-75 

 9-55 



24-3 

 8-5 

 9-7 

 9-7 

 11-3 

 11-3 



