CHARCOAL BURNING IN JAPAN 



By Dr. SHOZABURO MIMURA, Forest Expert 



Charcoal is an article of particular importance in Japanese house- 

 hold owing to the construction of the houses without chimneys. The 

 consumption of this wooden products amounts to some 1,000,000,000 kilos 

 a year. To supply this, the coppice wood from an area of 5,000,000 a. 

 is needed; that is, an enormous area of about 200,000,000 a. should be 

 provided as reserve with a 40 years' rotation. This clearly shows that 

 the charcoal industry and the means of improving it are matters of great 

 importance in the study of forest economy. 



Japanese charcoal is classified roughly as follows: — 



(1) Kurosumi or "Black Charcoal." 



(2) Shirosumi or " White Charcoal." 



"Black charcoal" is a product which is perfectly carbonized in the 

 kiln and which is taken out from it after the perfect extinction of the 

 fire inside, by closing both the chimney and air passage. The product 

 obtained is characterised by its peculiar black color, hence the name derived. 



"White charcoal" is produced by unclosing the mouth as soon as 

 the perfect carbonization of billets sets in to accelerate the oxidation 

 process inside. By this process the temperature evolves to the red heat 

 and the temperature of charring rises considerably, so producing harder 

 charcoal. After the standing of red heated charcoal for some time, it 

 is taken out from the kiln and a mixture of moist charcoal dust and 

 ashes is spread over extinguishing the fire. In this process not only the 

 bark of billets but also the outer parts are turned into ash forming a 

 white coating, hence the name derived. 



" Black charcoal " is generally soft and kindles easily but has weak 

 burning power while " White charcoal " is characterised by its difficulty 

 in kindling and its strong burning power. 



In order to produce " White charcoal," naturally a stronger heat is 

 needed for the carbonization and the kiln must therefore be strongly 

 built. " Black charcoal " is generally burnt in an earthen kiln while the 

 kiln for "White charcoal" should always be made of stone. 



