History of Technology in India, Vol. I: From Antiquity to c. 1200 A.D. v1.c13.s2.t4.98

v1.c13.s2.t4.98

The furnace bottom was prepared as explained earlier and after fixing the clay tuyere and bellows in position and closing the front hole the furnace was lit after performing the puja and charging it with charcoal. The furnace temperature was raised by operating the bellows at slow pace. When the furnace was red hot and CO gas was seen burning at the top. The furnace was charged with pre-heated ore and charcoal in alternate layers. The preheating of the ore was done by storing it on the inclined platform (*mācān*). *Table 5* gives the charging schedule and operating parameters of the Jiragora and Bishunpur and the latter furnace under operation. An oil lamp can be seen put near the furnace to take precaution against CO gas poisoning. The four thermocouples fitted in the furnace to record the inside temperature are also visible in this picture.