— 71 — 



(b) Temperature observed at the moment of the introduction 



OP AIR AFTER THE CARBONIZATION 



(Outside Kiln Extinction Method) 



This will readily show that the " Nerashi " (Finishing ignition) in the 

 " Outside Kiln Extinction Method " does not exceed 900°C. ; this is doubtless 

 due to the partial formation of carbon mono-oxide in place of carbon 

 dioxide caused by the limited supply of air on the red heated charcoal in 

 the kiln. 



Fig. 2. Position of segel-kegel introduced in stone Kiln. 



We can readily see from these tables that the temperature needed 

 for the carbonization of charcoal in a Japanese kiln seldom exceeds 600°C. ; 

 and that the heat rises up to 900°C. where " Finishing ignition" is carried 



