— 67 — 



" Dogama-zumi " or " Earthen kiln charcoal " is the designation given 

 to soft charcoal in contrast with hard charcoal which named " Ishigama- 

 zumi " or " Stone kiln charcoal." 



It would be more appropriate to classify the two methods as " Inside 

 Kiln Extinction Method," in the case of " Black charcoal " and " Outside 

 Kiln Extinction Method" for the production of "White charcoal" and 

 this nomenclature is adopted in this treatise. 



I. Construction of Japanese Charcoal Kilns 



The charcoal burning in its primitive form in Japan dates back 

 to somewhere between the 9th and 10th centuries. After gradual advance 

 in the construction, the so-called " Ikeda Method " came into first 

 existence on 1563 ; later the so-called " Bincho Method " and " Sakura 

 Method " came also into use in 1687 and 1797 respectively. Of these, the 

 " Ikeda Method " is somewhat dissimilar from the other two types of 

 later device, and it is now but little used. Bincho and Sakura kilns are 

 much alike in shape, and are only distinguished by the fact that more 

 stone masonery is used in the former than in the latter and particularly 

 by the double height of borders (koshi) of the former. 



For sake of brevity we shall only mention the general constructions 

 of the kiln which are common to both kinds. 



The base of the kiln used in charcoal burning in the country is 

 either oval or eliptical, dug out of the needed depth. In the case of a 

 stone kiln, the bordering wall is made of massive stones, but in an 

 earthen kiln only the mouth and flue passage are made of stones while 

 the rest is of earth. Inside the kiln wall, billets are piled up endwise 

 and upon these billets, small sized split wood is so disposed as to form a 

 paraboidal dome. Over this, an earthen covering is put and is tramped 

 down to make a perfect roof. 



Through the mouth, the contents are gradually kindled so as to dry 

 up the wood at the top first. After burning sometime a stronger fire is 

 set up to ignite the billets forming the back of the roof. At the lower 

 part of the mouth an air passage of 1-2 inches wide is left and the 

 rest of it is closed gradually admitting necessary air to cause imperfect 

 oxidation of the billets. The progress of the burning can best be dis- 

 tinguished by the color of smoke evolved. 



