THE ANATOMY OF A STEEL RAIL 1 



BY HENEY COOK BOYNTON, S. D. 



Metallurgist for J. A. Roebling's Sons Co. 



WHO would ever think, to look at a dull fragment of iron 

 or steel, that such a piece of metal had an internal history ! 

 But if this same inert, apparently insensible, piece of metal 

 be polished and suitably prepared for examination under 

 a microscope, its internal structure is more clearly and 

 surely shown than is the interior skeleton of a man by the 

 X-ray. 



However shapeless or structureless this piece of iron or 

 steel seems to be, it is now perfectly easy to show by a 

 proper treatment what the metal is composed of, how it 

 was treated, and what makes it good or bad ; in fact its 

 entire "family skeleton" can be exposed with the greatest 

 of ease. If it was created good, and has since degenerated 

 through hard usage or abuse, or if it was predestined to be 

 bad all its life, these properties and a great many more 

 can be shown with an ordinary compound microscope. 



It was only a few years ago that any intelligent engineer 

 would have said, ' ' If you will tell me the chemical composi- 

 tion of your metal, I will tell you whether it is of good or 

 bad quality." This statement has been lately proved to be 

 absurd. He might just as well have said, "If you will tell 

 me how much carbon, oxygen, hydrogen, nitrogen, etc., 

 there is in a certain man's body, I can tell you if he is a 

 good healthy fellow." 



Many times lately has the engineer's statement been dis- 

 proved. A boiler explodes and scalds many men ; an 

 apparently sound rail breaks under the load of the "Light- 



1 Published in Harper's Monthly Magazine for March, 1906. Copy- 

 right, 1906, by Harper and Brothers. 



56 ' 



