252 The Farm Woodlot 



requires the initial cost of a large iron tank and more fuel 

 to keep a large body of creosote at a high temperature, 

 but the method of application is much more rapid, and 

 when there are any number of posts to be dipped, it is 



Fig. 54. — A United States Forest Service plant for the preservative 

 treatment of fence posts. 



cheaper then the brush method. It is the best method of 

 treatment aside from the actual impregnation of the 

 woods. 



Open-tank treatment. Figs. 54, 55 



The open-tank method is peculiarly adapted to the 

 treatment of fence posts, poles, ties or other small timbers. 

 The same apparatus is required as for the clipping process ; 

 an iron tank fitted with a fire box or steam coil for raising 

 the temperature of the creosote. Slightly better results 



