Periodical Literature. 137 



2. The usual opinion that the quahty of the charcoal is the 

 better and the quantity the larger the slower the process is erro- 

 neous. Not a slow but a progress adapted to conditions — some- 

 times even moderately accelerated — gives best results. 



3. The smoke holes of a coaling zone must be kept open until 

 the smoke becomes light blue. During this stage of blue smoke 

 the gases escape which otherwise may cause collapse of the meiler, 

 and the coal then gets its proper density. 



4. For a continuous progress of the coaling process a certain 

 amount of air is needful, otherwise quality suffers and even pro- 

 gress is not possible. 



The results of a series of experiments on the behavior of the 

 different sizes of wood showed : 



1. With the same amount of air coaling progresses the faster 

 the smaller the wood. 



2. To secure the same quality of coal the progress must be 

 faster with small wood than with stout wood. 



3. To char stout wood requires more air. 



4. Quantity production is larger from young wood or from the 

 younger parts of stems, than from old wood. 



5. The weight of beech charcoal is highest from young stem 

 wood, then from branch and split wood, while overmature wood 

 makes the lightest charcoal. 



Regarding the size of meilers, it was found that: 



1. The size of the meiler must be adapted to size of wood: the 

 stouter the wood the larger the meiler. 



2. When the wood is too large the process of coaling progresses 

 with difficulty, and the labor cost is greatest. Split wood and 

 small billets coal the cheapest. 



Regarding the length of billets, experiments with sizes varying 

 from 3 to 6 feet : 



1. Both larger volume and greater weight is secured from short 

 wood. The difference between shortest and longest was 3.3% in 

 weight, and 6 to 9% in volume. 



2. The coaling proceeds too quickly with long wood for good 

 results. 



