150 THE BOOK OF FORESTRY 



before shipment they greatly diminish the weight and 

 the shipping charges. The balance of the seasoning 

 takes place in the yard of the retailer. 



Most of the large lumbermen at the present time 

 are drying their product artificially as much time is 

 saved and thus a large stock of lumber is not kept on 

 hand. Timber is seasoned artificially by placing it in 

 a kiln and heating to a comparatively high temperature 

 for a short time. Heat, however, must be very carefully 

 applied as too rapid drying will result in warping and 

 cracking. 



Certain hardwoods require skillful treatment and in 

 order to get the best material such grades as maple 

 flooring must be handled with especial care. 



Charring Timbers. A crude method of preventing 

 decay in small timbers, which is partially a chemical 

 method and partially seasoning, is often practiced with 

 round timbers in the country, especially fence posts. 

 This consists in charring the timbers before they are put 

 into the ground. The application of heat serves to dry 

 out thoroughly the exterior portion of the post, and 

 in addition, by changing the last two or three annual 

 rings to charcoal, a coating of material little subject 

 to decay is put around the part that is exposed to 

 dampness. 



Chemical Preservation. Regarding chemical methods 

 of wood preservation practiced in this country several 

 kinds are used, depending upon the size of the timber 

 and the equipment available. A good many chemicals 

 have been used at one time or another but at present the 

 list has been greatly reduced. To get perfect preserva- 

 tion the substance used should be poisonous to fungi, 

 easily soluble so as to penetrate deeply and should be 

 quite lasting. It can be readily seen that these qualifi- 



