^fif|4 Mr, John Tai/lor on the Smelting of [June, 



obtained by agitating it in the kettle for some time by an opera- 

 tion which they call tossing : this is ))erformed by a man with a 

 ladle, who continues for some time to take up some of the 

 melted metal, and pour it back into the kettle from such a height 

 as to stir up the whole mass and put every part into motion. 



When this is discontinued, the surface is carefully skimmed, 

 and the impurities thrown up are removed; these consist of such 

 matters as are lighter than the tin, but which are suspended in 

 it, and, being disengaged by the motion, find their way to the 

 top. In general, the metal is at once laded into the moulds, 

 after the tossing and skimming is completed, but the produce of 

 impure and irony ores may yet require that the tin be divided as 

 much as possible from the mixture which may yet remain. This 

 may be effected in a great degree by keeping the mass in the 

 kettle in a melted state, by which the parts which are heavier 

 than the tin will sink to the bottom, and by leaving a proper 

 portion behind, the tin will be materially improved. 



The last operation is that of pouring the metal into moulds, 

 which are usually formed of granite, and which are of such a size 

 as to make it into pieces of somewhat more than three hundred 

 weight each. These are called blocks, and are sent according 

 to 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 Refined 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 dress- 

 ing other ores. The stream tin is generally made very clean, 

 and is carried in this state to be sold for smelting, to establish- 

 ments which are called Blowing-Houses, being thus distinguished 

 from SraeltingHouses 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 smelt- 

 ing 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 



