366 
Mr. Taylor on the Smelting of Tin Ores 
the provisions of the Stannary Laws, to be coined by the Duchy 
Officers, and it then comes to market under the name of Block Tin> 
or a certain part which has been treated with more than common 
care, is called Refned Tin . 
The making of Grain Tin from the ores from stream works is 
conducted in a manner altogether different, and remains to be 
described. 
I have pointed out the purity of these ores, as regards their 
freedom from a mixture of other metals, and I do not think it 
important here to describe the mode of separating them by 
washing from the sand and gravel in which they are found, 
because the processes are very similar to those in use for dressing 
other ores. The stream tin is generally made very clean, and is 
carried in this state to be sold for smelting, to establishments which 
are called Blowing-Houses, being thus distinguished from Smelting- 
Houses in which Mine Tin is reduced, and the term is also 
descriptive of the process employed. 
The reduction of the ores for Grain Tin is performed by blast 
furnaces, and the only fuel used is charcoal. This mode of 
smelting is exceedingly simple, and is probably the most ancient 
one, as would appear from relics sometimes met with of furnaces of 
rude construction, and in some of which the wind alone seems to 
have been depended on for urging the fire. 
The furnaces now in use are similar to those met with for 
smelting iron in foundries where the blast is used, and are formed 
by a cylinder of iron standing upon one end and lined with clay or 
loam. The upper end is open for receiving the fuel and ore 
which are thrown alternately, and a hole at some distance from the 
bottom at the back of the cylinder is provided to admit the blast, 
aud another, lower down and opposite to it, suffers the metal to 
flow out regularly as it is reduced. 
