358 [Assembly 



export trade, and of that we take nearly one half, leaving little more 

 than one fourth for the rest of the world. We are at present the best 

 market the English have for fine cutlery, and not many years ago we 

 were wholly dependent. Grant Thornburn, in his '' Men and Manners 

 in Britain," mentions, " that in the year 1810, when the English Par- 

 liament was debating the policy of enforcbg its orders of council, and 

 thus making war on this country, one of the blustering fools in the 

 House said, ' that were it not for England, the men in America would 

 have to go with long beards.' " 



In the manufacture of iron the ore is generally first calcined by 

 burning it in heaps with coal or charcoal, to free it from water and 

 carbonic acid, the loss of which is about thirty per cent, on the whole. 

 The calcined ore is then transferred to the smelting furnace, generally 

 forty or fifty feet high, and divided into four portions, which act some- 

 what differently on the ore. In the lowest is the hearth or crucible, and 

 near its bottom are the openings of the tuyeres or blowing holes for 

 air to keep alive the burning of the fuel. The fuel, whether coke, 

 charcoal, or anthracite, is carbon ; and the ore is oxide of iron or 

 iron and oxygen. The carbon of the fuel unites with the oxygen, 

 forming carbonic acid, which escapes ; the iron melts, collects below, 

 and is drawn off at intervals, and run into sand moulds : the casting, 

 from its resemblance to a sow with a litter of pigs, being called pig 

 metal. It is not yet, however, pure iron, for in melting it took in a 

 little carbon, which gave it the property of melting so readily : this 

 is cast iron. 



In the smelting furnace, lime is always added for uniting with the 

 earthy and sandy matters of the ore, as it forms a glass which floats 

 on the surface of the melted metal, and is drawn off as slag. 



In the conversion of cast iron into malleable or bar iron, it has to 

 undergo the processes of refining and puddling, by which it loses the 

 carbon which before it was imbued with, and which gave it the fusi- 

 ble property ; as it loses this carbon it becomes less fxisible, more 

 pasty, and ultimately tough, in which state it is passed into the rolling 

 mills, whence it comes out as bar iron. 



