20 



damage by timber worms, as will also coating or spraying with 

 preservatives. 



Repellent, poisonous, or stickly chemical sprays, to prevent attack 

 by ambrosia beetles on more valuable species and products, can be 

 used where the bark is on the logs and the wood will not be dis- 

 colored (12). The preservative coating known as hardened gloss 

 oil has the advantage of preventing checking. 



Green lumber should be kiln-dried (49) ; or, where this is not 

 practicable, piled on stickers (7), to insure rapid air seasoning. Air 



m% 



1M 





■J's/W 



mm mm III11! 





Fig. 22. — Grub holes made by the oak carpenter worm (Prionoxystus roMniac) 



seasoning of green freshly sawn timber or lumber by open or loose 

 piling is a preventive. In cribbing or proper piling of green sawn 

 stock to facilitate rapid drying, care should be taken to insure against 

 severe checking from too-rapid drying. Heavy dimension timber 

 should be stacked in loose piles. If it were possible to kiln-dry the 

 material, insect damage, of course, would be prevented. 



In the case of damage to stave stock, by special methods of sawing 

 the waste can be reduced to a minimum and a very considerable 

 saving of material effected. Where the holes are not too numerous, 

 they can be plugged with wooden pins and the wood used for casks. 



