CHARCOAL-MAKING. 545 



the wood so that they overlap one another like tiles. The outer 

 covering consists of a paste similar to that used in ordinary 

 kilns, or the same mixed with damp earth. 



In order that this paste may adhere to the vertical walls of 

 the kiln, the latter are supported by poles placed 6 to 8 inches 

 apart along the two sides of the kiln, and its front (Fig. 319), or 

 in Steiermark the whole kiln, is surrounded by planks (Fig. 318) 

 resting on horizontal logs (n n n, Fig. 319), to secure a draught 

 of air. The paste is applied between these planks and the 

 ends of the logs, and is rammed down. The back of the kiln 

 is, in Sweden, supported by props (c c c, Fig. 317). The roof is 



Fiir. Ml'.'. Back wall of a horizontal kiln. 



at first only thin, and is thickened after the kiln has been fired, 

 when there is no longer any danger of its bursting. 



(v) In order to fire the kiln, the kindling flue, or chamber, is 

 filled with readily combustible material, the filling being con- 

 tinued with an open flue until the kiln is thoroughly alight. The 

 whole front portion of the kiln must burn if the fire is to con- 

 tinue uniformly throughout. Once this has been secured the 

 kindling flue, or chamber, may be closed, and the combustion 

 continued by opening successive vent-holes in the roof (in Steier- 

 mark also in the sides of the kiln), as in the ordinary method. 



Carbonisation proceeds obliquely backwards, the fire being 

 always more advanced towards the roof than at the base of 

 the kiln. Thus the base of the back of the kiln is the last to 

 be carbonised, and the process is completed as soon as flames 

 emerge from ventholes there. The charcoal is cooled by 



F.U. N N 



