The Durability and Preservation of Woods 251 



coat should be applied. The application of a third coat 

 does no good. In cold weather this process is not very 

 satisfactory. The creosote, coming in contact with the 

 cold wood and the cold atmosphere, solidifies so quickly 

 that it does not have a chance to soak into the wood. 

 The hardened first coat forms a shell through which the 

 second coat seldom penetrates. 



Even under the best conditions, the penetration ob- 

 tained under this process is very slight, seldom averaging 

 over one-sixteenth of an inch. Provided the cracks that 

 already existed in the wood are thoroughly filled, which 

 is far from certain in this process, the post is entirely free 

 from decay so long as it holds its original form ; but the 

 slightest check or crack that occurs after treatment 

 exposes the unprotected interior, and dry rot gets into the 

 wood, making the outer coating of preservative useless, or, 

 perhaps, even a means of conserving moisture for the use 

 of the fungi. This method is only good when a better 

 cannot be applied. 



Dipping 



Very good results are secured by dipping the posts into 

 hot solutions of creosote or carbolineum. The solution 

 should be kept at a maximum of 150° as before, because 

 creosote volatilizes very rapidly above that point. The 

 posts are dipped into the tank and laid away in some well- 

 ventilated place to dry. The penetration under this 

 method is not very much greater than with the brush 

 method, but a more even coating is obtained and the 

 submersion in the hot liquid opens up all the incipient 

 checks and thoroughly fills them with creosote. It 



