HARDWOOD DISTILLATION 207 



Inasmuch as the wood must be seasoned for between one and two 

 years, it is necessary to have a large, convenient and well-located wood 

 yard so that there should be at least six months' seasoned supply on hand 

 all the time. 



At a 35-cord capacity plant it is planned to have 10,000 cords of wood 

 as an advance supply continually on hand. 



The wood is usually cut in 50-in. lengths and stacked in long piles up 

 to 12 ft. in height on either side of the standard guage tracks from which 

 the unseasoned wood is unloaded from freight cars. In other cases 

 parallel roadways are left open for the wagons to unload directly from 

 the woods. Parallel tracks between these roadways are then provided 

 to load the wood cars for the ovens after seasoning. In cylindrical retort 

 plants the wood is commonly rolled in on wheelbarrows or open trucks 

 and loaded by hand. 



Retort House. 



The retort house is the largest building in the plant. It houses the 

 cylindrical retorts or oven retorts and, in some cases, the stills and appli- 

 ances for treating the pyroligneous acid as well. However, in the most 

 modern plants, the still house is a separate building. 



The principal requisite of a retort house is that it should be of fire- 

 proof construction on account of the very inflammable nature of charcoal 

 and wood alcohol. One retort house at a plant having a daily capacity of 

 38 cords is 60 ft. in width by 240 ft. long, 20 ft. high to the eaves and 

 40 ft. to the peak of the roof. Steel beams and supports are used through- 

 out with sheet-iron roof and siding. Other retort houses are either 

 built of stone or brick in order to reduce the fire hazard and, therefore, 

 obtain low insurance rates. Many plants are poorly arranged because 

 of their enlargements from rather modest beginnings, and no definite 

 plan seems to have been followed in the arrangement of the plant. 



Trackage and Cars. 



The tracks are usually standard gauge with the rails from 40 to 75 

 lb. in weight, and are so arranged as to bring the wood from the storage 

 yards to the retort house and then to conduct the cars loaded with 

 charcoal through the two sets of cooling ovens and out to the charcoal 

 shed, where the charcoal is loaded on freight cars. The most modern 

 plants have the progressive arrangement, that is, the loaded cars come 

 from the storage yards directly to the retort house; follow through in one 

 continuous direction to the first cooling oven and then to the second and 



