Obfervations on Iron and Steel. 49 



'which has been reduced with a fufficient quantity of fuel, of 

 which it contains a part in folution. The operation of re- 

 fining crude iron confifts in burning the combuftible matter 

 which it holds in folution ; at the fame time that the re- 

 maining iron is more perfectly reduced, and acquires a 

 fibrous texture. For this purpofe, the pigs of caft iron are 

 taken to the forge, where they are firft put into what is called 

 the refinery ; which is an open charcoal fire, urged by a pair 

 of bellows, worked by water or a fleam-engine ; but the 

 comprefiion of air in the refinery ought to be lefs than that 

 in the blaft-furnace. After the metal^is melted, it is let out 

 of the fire by the workmen to difcharge the fcoriae, and thert 

 returned and fubje&ed to the blaft as before. This opera- 

 tion is fometimes repeated two or three times before any 

 appearance of malleability (or what the workmen call coming 

 into nature) takes place ; this they know by the metal's firft 

 afluming a granular appearance, the particles appearing to 

 repel each other, or at lead to have no figns of attrac- 

 tion. Soon afterwards they begin to adhere, the attraction 

 increafes very rapidly, and it is with great difficulty that the 

 whole is prevented from running into one mafs, which it is 

 defirable to avoid, it being more convenient to ftamp fmall 

 pieces into thin cakes : this is done by putting the iron imme- 

 diately under the forge-hammer, and beating it into pieces 

 about an inch thick, which eafily break from the reft during 

 the operation. Thefe fmall pieces are then collected and 

 piled to the height of about ten inches upon circular ftones, 

 which are an inch thick and nine inches in diameter. They 

 are afterwards put into a furnace, in which the fire is rever- 

 berated upon them until they are in a femi-fluid ftate. The 

 workmen then take one out of the furnace, and draw it into 

 a bar under the hammer ; which being finifhed, they apply 

 the bar to another of the piles of femi-fluid metal, to which 

 it quickly cements, is taken again to the hammer, the bar 

 firft drawn ferving as a handle, and drawn down as before. 

 The imperfe&ions in the bars are remedied by putting them 

 Vol. I. E into 



