552 TRANSACTIONS OF THE AMERICAN INSTITUTE* 



If the experiment has not been tried of putting the ore and coal 

 directly into the furnace, I suggest that it be tried. 



Mr. Dibben. — The advantage of this arrangement is that the 

 ore and coal are partly heated for the puddling furnace by the 

 waste heat of the furnace. But the great difficulty in all these 

 direct processes of making iron, where no flux is used, is to get 

 rid of the silica and other foreign substances contained in th9 

 ore. 



Prof. Renwick. — I would aak if any other ore has been tried 

 than the Dickinson ore? The Dickinson ore is very easily re- 

 duced. It can be done in a common blacksmith's forge. There 

 is no difficulty in making a horse shoe from this ore at any black- 

 smith's fire. This plan of making wrought iron direct from the 

 ore, is the oldest of all processes, and is the one now in use 

 among barbarians. It requires, however, a very rich ore, and 

 has never yet been economical. 



Mr. Cooper. — Ten years ago there was in operation at the Trenton 

 Iron works, an apparatus precisely similar to this. It made good 

 iron, but there was a practical difficulty in the cylinder warping, 

 and it was laid aside. The iron would be reduced in the cylinder 

 in this way : A little atmospheric air would get in with the coal 

 and ore, and the oxygen of this air would combine with the coal 

 at red heat to form carbonic oxide ; then, as oxygen has a stronger 

 affinity for carbonic oxide than it has for iron, it would leave the 

 iron and combine with the carbonic oxide, producing carbonic 

 acid, and leaving the iron in the metallic state. The silex would 

 be got rid of as silicate of iron, thus reducing the yield of the 

 ore. 



Mr. Bartlett. — Very careful provision is made for excluding all 

 air, except that which fills the interstices between the particles 

 of ore and coal. As it takes thirty-three pounds of oxygen to 

 burn twenty-five pounds of coal into carbonic oxide, and as 

 oxygen forms only about twenty-three per cent, of the atmosphere, 

 it would r<^quire 150 pounds of air for each charge of ore and 

 coal. This would be equal to about 2,000 cubic feet of air — 

 enough to fill a room ten feet wide, ten feet high and twenty feet 

 long. This could not be contained in the interstices of 100 

 pounds of ore and coal. 



The Chairman. — The time has arrived for the discussion of the 

 regular subject selected a fortnight since. It is 



