144 



FOREST PRODUCTS 



more susceptible to leakage than white oak owing to its open pores. 

 (In white oak the pores are closed by means of tyloses.) There is a 

 growing tendency to use more and more substitute woods in the cheaper 

 grades of tight cooperage staves and heading. This condition, more- 

 over, is being aggravated by the growing scarcity of high-grade white oak 

 stock, the increasing demands for white oak for tight cooperage barrels 

 and the consequent rise in prices. 



Photograph by V. S. Forest Service^ 



Fig. 33. — This shows a method sometimes employed in riving sections of white oak logs into 

 stave bolts. Houston'Co., Tennessee. 



Where the seasoning and aging of the contained beverages are in- 

 volved, as mentioned above, all white oak barrels are charred on the 

 inside to an average depth of | to ^ of an inch. This has been univer- 

 sally the custom for a long time, especially with whisky barrels. 



The pure food laws passed by Congress and the increase in petroleum 

 and turpentine production greatly stimulated the demand for tight bar- 

 rels. As soon as these laws went into effect, there was a very strong 



