138 forestry Quarterly. 



3. Long wood requires more after filling than short wood, and 

 this accounts for the poorer result. 



4. With long wood the consolidation of the coal in the meiler 

 is impeded. 



5. In long wood the gases circulate more easily between the 

 charred parts and deteriorate them. 



6. The danger of explosives is greater with long wood. 



7. The labor cost increases with the length of the wood. 



An extensive series of experiments concerned itself with a com- 

 parison of the output of standing and lying meilers. The latter 

 are the easiest to manage, but the quality as well as quantity of 

 coal are inferior. The cause was found in the access of the erases 

 to the already charred wood, which deteriorate the coal. 



The meilers had been so arranged that they permitted access 

 to the interior during the process. 



The observations regarding the progress of the process were : 



1. The progress of the charring follows the incoming air rather 

 than the outgoing air whenever the source of air lies under or in 

 front of the coaling zone. It is impossible in the lying meiler to 

 lead the coaling upward. 



2. The charring has a tendency to progress more rapidly at the 

 base and towards the base. The position of the base whether 

 rising, falling or horizontal, influences the progress in the lying 

 meiler, just in the same manner as in the standing meilers. 



In the lying meiler only straight wood of even length can be 

 advantageously used ; otherwise, labor cost becomes excessive, 

 hence it is altogether uneconomical where the better class wood 

 has another use. 



As to the progress of coaling in standing meilers it was found : 



1. In standing meilers the process can never be guided other- 

 wise than from the top downwards. 



2. It requires a centre around which the whole process moves, 

 from which it progresses in all directions evenly. 



3. Best results are obtained when the wood is seasoned or if 

 a "forewarming" of the meiler is made, i. e. a light glowing is 

 maintained in the middle of the meiler until the wood is of proper 

 dryness. 



