170 



Note 7. — The U. S. Department of Agriculture has figures which 

 indicate a consumption of cordwood for IHinois as follows: 



1917 2,400,000 cords 



1919 1,896,000 cords 



1920 1,422,000 cords 



1921 1,659,000 cords 



These figures are considerably in excess of the deductions made by 

 this study and, if correct, indicate a production of cordwood for 1921 

 of .591 cords per acre of woodland for the state, in addition to the yield 

 of all other products. It is not thought that such yields are probable. 

 If correct, it indicates a still more rapid exhaustion of the forests of 

 the state by over-cutting. 



Note 8. — For cordwood, 80 cubic feet is taken as the converting 

 factor. For saw-timber, the lumber output is reckoned as requiring 1 

 cubic foot from the tree to produce 6 board feet, giving a factor of 

 ■ .16%. For fence posts, an average size of 4 inches at the top end of a 

 7-foot post was fixed, giving about .8 cubic feet per post. For cross- 

 ties, 35 board feet per tie, and 8J/S board feet per cubic foot gave 4.25 

 cubic feet per average tie. allowing for waste in hewing. 



Mine timbers were estimated directly in cubic feet by converting 

 factors as follows : 



Mine props 83 cubic feet 



Bars and legs 1.91 cubic feet 



Mine ties 70 cubic feet 



which was fotmd to be the average for material consumed in the mines. 

 (See p. 77 on consumption of timber in mines.) 



Piling was taken as averaging 22.3 cubic feet per piece. 



Note 9. — Tabulation of census figures for lumber production by 

 decades in Illinois shows 334,244,000 B. F. in 1879 and 56,900.000 in 

 1920. During the eighties and nineties the relatively high production 

 was largely accounted for by logs imported from other states. During 

 the eighties Rock Island county produced annually 70,000.000 B. F., lead- 

 ing all other counties. The second in amount at that time was Massac 

 county with 14,000,000 B. F. The Rock Island production was from 

 Wisconsin and Minnesota white pine logs, the Massac from both local 

 and imported hardwoods. The importation of logs into southern Illi- 

 nois is probably still considerable, but it is negligible elsewhere. 



