Lead . 
203 
Cumberland, Durham, and Northumberland, smelting is 
performed in the ore hearth by means of bellows. In 
some parts of Yorkshire, in Derbyshire, and in North 
Wales, lead is smelted in reverberating furnaces : this 
kind of smelting is distinguished from the other by the 
name of cupola smelting : each of these methods has its 
advocates. 
The superiority of either depends much on local cir- 
cumstances, and, perhaps, also on the skill of the work- 
men. 
Ore-hearth smelting shall be first described.—To ren- 
der the description intelligible, it will be necessary to 
commence with a description of the hearth. 
Fig. 1, of the plate, is a sketch of the hearth : it is con- 
structed principally of pieces of cast iron, which are called 
generally iron stones or metal stones ; each different cast- 
ing has a distinguishing name : they are the (a) pan, (6) 
back, (c) pipe-stone, (d) spark-stone, [e) bearers, (f) 
keys, (g) fore-stone, and the (h) work- stone. 
The hearth is erected under a spacious chimney, and 
nearly in the centre ; one side of it is called the water- side, 
being near the water-wheel, which urges the bellows ; the 
opposite is called the land- side. 
Figs. 2 and 3 are plans and sections of the ore-hearth : 
the same letters in the different figures are placed to the 
same parts.— (i) the floor of the smelting- house, [k) the 
back of the chimney, (/) the front of the chimney, (m) the 
foundation on which the hearth is constructed : it is built 
of rough masonry, and levelled and run in at the top with 
thin mortar or grout ; the pan or bottom of the hearth is 
laid steadily in mortar on this bed : upon the posterior 
part of the pan is placed the back, its face being even with 
the inner edge of the pan. 
The work- stone is next arranged ; its upper edge three 
or Four inches from the anterior part of the pan* and pa~ 
