THE COMMOX METHOD. 701 



the upper part of the flue being somewhat loosely filled with 

 broken branches, half-burned bits of wood, shavings, &c. When 

 the kiln is kindled from above, the flue is filled in the reverse 

 manner. 



The flue once filled, finely-split pieces of dry wood and partly- 

 carbonised billets are placed round it, the spaces between them 

 being filled with w^ood-shavings, and then the regular kiln is 

 constructed. This is done by piling two tiers of billets, the 

 burner placing dry pieces of wood as closely as possible round 

 the shaft, with their split sides inwards, followed by larger 



pieces, so that at a distance of about half the radius of the kiln 

 the thickest pieces, which burn most slowl}', are placed, and 

 smaller billets outside these, as shown in fig. 310. After some 

 progress has been made in the lower tier of billets, the upper 

 tier is commenced and the tw^o tiers continued together till the 

 kiln has attained its full circumference. 



If the kiln is to be kindled from below, a kindling-passage is 

 left communicating with the flue ; this is effected by placino- 

 a thick log on the ground from the opening in the flue to the 

 edge of the kiln, which is gradually drawn away during the 

 piling of the lower tier, leaving a hollow^ passage. The billets 

 placed above this log should be somewhat shorter than the rest, 

 so as to secure a level surface to the lower tier. This passaf^e 

 should always be exposed to windward, but is not required if the 

 kiln is kindled from above. 



When the two tiers of billets are piled the top of the kiln is 

 filled in, as shown in fig. 310. For this the wood, which should 

 be composed of small dry pieces, is laid very obliqudy or hori- 



