JAPANESE CHARCOAL KILN. 

 By Nils B. Eckbo. 



There is a great deal more charcoal used in Japan than in any 

 other country, and it is a necessity in every Japanese household. 

 According to statistics of the year 1906, the quantity of charcoal 

 amounted to 956,422 tons which represents a value of about six 

 and a quarter million dollars. 



The burning of charcoal has been known for centuries ; while 

 the methods naturally have had their course of development. The 

 method described here is the one used most commonly throughout 

 Japan, and the construction of the kilns in their most complete 

 form is shown in the accompanying illustrations. As the woods- 

 man and farmers make it, it is somewhat simplified, which can be 

 seen clearly in the photographic reproductions. 



The kiln is most easily made in a clay hillside where it can be 

 dug out with four to five feet high walls. These may also be made 

 of stone, which is a little more expensive, but makes a whiter 

 charcoal, which is more valuable than the black. The entrance is 

 made of three stones and one hundred bricks, the bottom of the 

 chimney is also constructed of stone with about one hundred 

 bricks composing the funnel. Wood of broadleafed trees is used 

 exclusively and is cut as long as the wall is high, then piled verti- 

 cally from back towards the entrance. On the tops are laid 

 shorter pieces so as to make a properly curved roof, which is cov- 

 ered with straw mats. 



The roof of the kiln is made of burnt clay and water, the clay 

 being pounded into a layer of three to five inches in thickness 

 and with a perfectly smooth surface. This is practically airtight, 

 and when burned becomes hard as brick and cracks with difficulty. 

 In the entrance are put two rows of round wood, about one foot 

 in diameter, to prevent too much draft, and the kindling is started 

 under a small canopy made of clay in front of the entrance. 



As the fire spreads, during the first seven to twenty-four hours, 

 one-half of the entrance is closed gradually with rocks. At the 

 end of seven days, pale smoke usually emanates from the chimney, 



