No. 216.] 223 



made. I arrive at different conclusions from Mr. Mushet, as the 

 minute quantity of carbon in any bar of iron would not be a cause 

 of trouble to the workmen, nor of complaint in the uses to which it 

 is applied. 



Common bar iron is a natural alloy of the several metallic bases 

 of the earth with which it is associated. The separation of these 

 leaves the iron in the state of chemical purity, and if iron were thus 

 purified, we should have no distinctive or different qualities. This is 

 what I have succeeded in doing, so far as the purity of the metal is 

 concerned, but this is not the only objection to the use of this metal 

 which I have overcome. 



Bar iron is very imperfect in its mechanical structure, having 

 merely a series of the lamina interspersed with the scoria of the 

 smelting process, which being mixed with the metal, are still retained 

 by the lamina to whatever length they may be drawn out, and from 

 which no subsequent welding or working of the bar can possibly free 

 it. We have before us too many proofs that iron once separated, can 

 never again, even undier the most favorable circumstances, be perfectly 

 united, by any process of welding. 



This iron being chemically pure and mechanically perfect, its 

 superiority for almost any of the purposes of art, are too obvious to need 

 enumeration. It may not be superfluous for me, however, to mention 

 a few instances where its application would be of service to the art. 



Our ingenious and scientific countryman, Jacob Perkins, has long 

 felt and expressed the want of such iron in an art invented by 

 himself, for copying his engravings, by transferring them to rollers — 

 a process now generally adopted by engravers, and by whom its 

 importance will at once be seen and appreciated. The common 

 practice with them now, is to take *cast steel, and after forming it 

 into the shape wanted, to decarbonize it on the surface in order that 

 it may receive the impression of the engraving. It is then again 

 submitted to the process of case hardening, in order to render it fit 

 for the intended purpose, viz: to imprint other steel plates with. 

 But here is its value more perceptible, for the plate cannot be hard- 

 ened (if large) without imminent danger of breaking. For this reaso 

 it is left soft, and soon becomes worn out in the hands of the printer, 

 whereas, if the plate would admit of being hardened^ it would give 

 any number of impressions. Thus, if a large picture or map which 

 cost its engraver some hundreds of dollars, and from which only a 



