na 



WOOD-CARBONISATIOX. 



possible, iiiul iutcrstices filled iu with split wood. The flue is 

 formed, as may be seen from fig. 315, a, by placing several logs 

 around a cylindrical hole running from side to side of the kiln, 

 or as in fig. 316, a, a kindling chamber is left open, as is 

 customary in Steiermark. 



(iv) The kiln is now covered ; the inner covering is usually 

 spruce or silver-fir twigs, the lower ends of which are stuck into 

 the wood so that they overlap one anoth(;r like tiles. The outer 



covering consists of a similar plaster to that used in ordinary 

 kilns, or the same mixed with damp earth. 



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

 the kiln the latter are supported by poles placed (5 to 8 inches 

 apart along the two sides of the kiln, and its front (fig. 317), or 

 in Steiermark the whole kiln, is surrounded by planks (fig. 316) 

 resting on horizontal logs (ii n ii, tig. 317) to secure a draught 

 of air. The plaster 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 (r c c, fig. 315). The roof is 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 Hue until the kiln is thoroughly fired." 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 (•hiinil)er may be closed, and the combustion 



