280 ILLINOIS ACADEMY OF SCIENCE 



The average diameter growth on the stump for these 

 same 37 white oak trees was 1.7 inches for the last decade, 

 a very good growth for this class of soil. 



Products from Forests of the Ottawa Region. 



Piling. 



According to the men cutting piling, the only species 

 which would be accepted are white oak and bur oak. 

 Piling must have a butt diameter when peeled of not less 

 than 13 inches, with a 7 inch top. The length must be not 

 over 50 feet, nor less than 20 feet. The men receive II/2 

 cents per linear foot for cutting and peeling. Piling is 

 sold at a stated price per linear foot for specified dimen- 

 sions, the price increasing rapidly with increase in length 

 and in desirability of form or taper. One acre of average 

 white oak in this country would produce, according to 

 our estimate and by actual count on the ground about 873 

 linear feet of piling, with an average length of 25 feet. A 

 white oak tree 16 inches in diameter inside the bark on the 

 stump will produce a pile 40 feet in length and top 

 diameter of 6.5 inches, with a volume of 29.2 cubic feet in 

 about 76 years, or an annual volume growth of .384 cubic 

 feet. 



Mine Props. 



Mine props are cut from any species, except poplar, and 

 may have the following sizes : 



