CHARCOAL 243 



coal per cord of wood. The time required for filling, burning and empty- 

 ing the charge in the case of the larger kiln of rectangular shape is about 

 four weeks and for the smaller one about three weeks. 



About three weeks are required for the operation on the average 

 outdoor pit containing about 25 to 30 cords of air-dry hardwoods. One 

 man can usually tend two pits at a time if located close together. A 

 crew of 5 or 6 men will look after 3 or 4 pits generally, while another crew 

 chops, piles, transports the wood, and erects the piles, and bags and 

 transports the charcoal to market. 



The location of the pits of the open-air style can be changed from 

 place to place, convenient to the source of wood supply, all that is neces- 

 sary being the leveling and clearing of the space 40 to 75 ft. in diameter. 

 In the case of the brick ovens or kilns, the wood must be transported 

 much greater distances. Although the yield from the old-style pit is not 

 as great as that from the beehive or rectangular oven, it is claimed that 

 the charcoal made in the open pits is superior to that made in the ovens. 



The conditions and the rate of burning in open-air pits depends upon 

 the following factors: 



1. The kind of wood. Dense hardwoods of high specific gravity 

 are the best for making charcoal. The conifers are much 

 inferior, dependent upon their weight. Heavy woods require 

 much more time for burning. For the manufacture of certain 

 kinds of charcoal iron, however, a mixture of hardwoods and 

 soft woods is considered best. 



2. The size of wood used including the length, thickness, regularity 

 and straightness of the individual billets. Large pieces obvi- 

 ously require much longer time for burning than thin, slender 

 pieces. The best size is billets 3 to 4 in. in diameter, or billets 

 from 6 to 9 in. in diameter that have been quartered. 



3. Condition of the wood. It should be well seasoned, but never 

 doty or partially decayed or rotten. Wood free of knots and 

 other defects makes much better charcoal than that containing 

 large knots and frequent defects. 



4. Condition of the ground. It should be perfectly dry, soHd, 

 level and free from draft. The latter is very important. In a 

 loose, sandy or gravelly soil, air may be drawn in from under- 

 neath and, therefore, the draft may be beyond the control of 

 the operators. 



5. The time of year. The best time is from July to September or 

 October, the wood having been cut the previous winter and 



