AMERICAN INSTITUTE. 529 



The obelisks of joorphyry, made by ancient Egypt, are covered 

 by vast numbers of inscriptions. Yet we have no tools of steel 

 that can do it, nor do we know of any other mode of cutting such 

 inscriptions, except by emery dust or diamond dust. 



Aristotle said that wrought iron itself may be cast so as to be 

 made into a liquid and then to harden again, and steel is made 

 thus. The scoria of the iron settles to the bottom and the steel 

 remains above; and after being melted several times, it is at each 

 melting defecated, (got rid of spurious matter,) it becomes steel. 

 There is much waste in this process. 



Agricola of Saxony, 1494, gave the following account of making 

 steel : 



" Make choice of iron which is apt to melt and is yet hard, 

 which can easily be. wrought with the hammer, for although iron 

 which is made of vitriolic ore may melt, yet it is soft, or fragile, 

 eager. Let a parcel of such iron be heated red hot and cut into 

 small pieces and mixed with a sort of stone which melts easily, 

 then set in the forge or hearth a crucible a foot and an half broad 

 and a foot deep; fill this dish with good charcoal and compass the 

 dish about with loose stones, which may keep in the mixture of 

 stone and pieces of -iron put thereon. 



"As soon as the coal is thoroughly kindled and the dish is red 

 hot, give the blast and put on little by little on the mixture of 

 iron and stone. 



"When melted, put into the middle of it three or four or more 

 pieces of iron and boil them then five or six hours with a sharp 

 fire; stir the melted iron often that the pieces of iron may imbibe 

 the smaller particles of the melted iron, which particles consume 

 and thin the more gross particles of iron pieces, and are as it were 

 a ferment to them, and make them tender. 



"Now take out one of the pieces and put it under the great 

 hammer, draw it out into a bar and then, hot as it is, forthwith 

 plunge it into cold water. Thus tempered, work it on the anvil 

 and break it, then examine the fragments and judge whether it 

 looks like iron, in any part of it, or is wholly condensed into 

 steel. 



