IX, A, 3 Dalburg and Pratt: Iron Ores of Bulacan 243 



times as many as a half dozen charcoal kilns located at favorable 

 places in the forest within convenient distances from the smelter. 

 The Filipinos in the iron industry have evolved a useful and 

 fairly efficient method of burning charcoal in connection with 

 their smelting practice. Formerly, they burned their charcoal 

 in pits, as is still the practice elsewhere in the Philippines. 

 Abandoned charcoal pits may still be seen near the old smelting 

 centers; they are often located in a side hill, and are circular 

 in plan, 3 meters in diameter and 2 meters deep, with an opening 

 or hearth on the down-hill side. A temporary covering or roof 

 of green wood and earth was provided, and the fire was controlled 

 by making this roof more or less impervious to the draft. 



The charcoal kiln now in use is built of bamboo, and is 

 entirely above the surface of the ground (Plate VI). It is 

 called an inglesa for the reason, it is said, that an Englishman 

 {ingles) who operated an iron smelter at Cupang in 1860 

 first used this type of kiln. An inglesa, or charcoal kiln, is simply 

 a rectangular inclosure, the walls of which are made of bamboo 

 poles; it is about 14 meters long, 4.5 meters wide, and 4.5 

 meters high. The logs for charcoal are cut into lengths 1 meter 

 shorter than the width of the kiln, and are corded up inside 

 the kiln with a space 0.5 meter wide everywhere between the 

 pile and the bamboo walls. About 30 per cent of the wood 

 in the kiln is in the shape of logs 0.5 meter or more in diameter, 

 while the remainder is graded in size down to about 10 centi- 

 meters in diameter. Openings which run longitudinally along 

 the floor of the kiln and up one end of the pile are provided 

 for maintaining a draft. After the pile is completed, the space 

 around it inside the walls is filled with fine charcoal waste and 

 a cover of the same material is spread over the top. The fire 

 is started at the lower end, and gradually burns through the 

 kiln, being retarded by the smothering effect of the charcoal 

 cover. Two burners are employed, who control the burning 

 by opening vents through the walls at proper places as the 

 carbonization progresses. By the time the burning is complete, 

 the pile has subsided to a height of 2.5 or 3 meters. It requires 

 anywhere from fifteen to thirty days to burn a kiln of 140 cubic 

 meters of charcoal. 



The charcoal is obtained in unusually large pieces, and is 

 hard and strong. Where wood is cut for charcoal on mining 

 claims, all classes of timber are utilized; the hard woods 

 of the first- and second-group trees make splendid charcoal. 

 Even where the wood is cut under license on public land and 



