220 



It would also pay mine operators to investigate the proposition of 

 treating with chemical preservatives timber that is to be used in per- 

 manent work. By such treatment the less durable woods will last as 

 long as the best white oak, and a large saving can be made in the 

 amount of timber used and in the cost of its replacement, 



SLACK COOPERAGE 



The slack cooperage industry draws heavily upon the supply of 

 bottomland timber in both the southern and northern parts of the state. 

 All of the common bottomland "softwoods" are readily made into 

 slack barrels with the exception of black gum and honey locust. Red 

 gum and elm are the most used for this purpose. The trees are usually 

 cut to a diameter limit of twelve inches at the stump by the southern 

 stave manufacturers; but in the northern part of the state, where 

 timber is scarcer, they are cut to a smaller limit, sometimes as low as 

 eight inches. The stumpage value of stave timber per thousand board 

 feet is $1.50 to $2.50 on the southern bottoms, and $2.50 to $3.50 in 

 northern Illinois. 



Table VIII shows the production of slack cooperage from native 

 timber in the year 1908, as obtained by the Forest Service in coopera- 

 tion with the Bureau of the Census. The figures for 1909 will probably 

 show a considerable reduction. 



Table VIII. — Production of Slack Cooperage in Illinois, 1908. 



