USEFUL PRODUCTS FROM COAL, 339 



eede the use of turpentine &c. in japanning; and I do hope, 

 that in time works of the same description will be establish- 

 ed through all Staffordshire, the products of which will sup- 

 ply the place of a great portion of tlie spirit used in the 

 kingdom, while the pitch will be of sufficient quantity to 

 form a great part of that article now used in the dock- 

 yards. 



All I want is support from the great coal companies and Requisites, 

 masters, to erect sufficient apparatus at the dififerent works, 

 to preserve the tar at all the eoke furnaces, and proper 

 means to separate the spirit from the tar. It would be a 

 great saving to the nation, as in every hundred weight of 

 coal coked there are lost by the present mode above four Present loss. 

 pounds of tar ; and the cokes are not half so good as if they 

 ■were coked in close vessels, to the exclusion of the atmos- 

 pheric air. I need not describe the method by drawings of 

 the manner of extracting the tar from pit-coal in close ves- 

 sels, as that method is so generally known ; it must be clear 

 to every one, that it is procured by distilling the coal. 



I have, as follows, described the method I use in extract- 

 ing the spirit from the tar, the process of which is so simple, 

 that every one must understand it. 



Fig. 2, PI. IX, is a section of the furnaces, and one of Method of ex- 



1 i , - , . , T . ,. tractincrthe 



the retorts, almost any numper of which may work in aline, spirit of tar. 

 the same flue will do for all, only taking care, if any are 

 not at work, to stop up the dranght-hole^ which communi- 

 cates with the flue. These furnaces are built without bars, 

 grates, or doors. A is the place where the fewel is put in Apparatus 

 to heat the retort G ; the fire lies under it, and the smoke 

 is carried off into the flue D. B is the aperture where the 

 ashes are raked out. G is a section of the iron basin, or 

 lower part of the retort; the dark-shaded square part 

 shows the space the fire occupies, and the black square D 

 the flue as it runs along the back of all the line of furnaces, 

 and enters the chimney R, as the arrows show. I, Figs. 2 

 and 3, shows the upper part of the iron, earthen, or glass 

 retort, fitted on the cast-iron basin G. K, the receiver. By 

 this mode of setting the retorts, all the great expense of 

 bars, doors, frames &c. is saved, and a brisker draught of 

 air is obtained, which may be slackened at pleasure bjr 

 Z % corerinj 



