268 Forestry Quarterly 



This article embodies a summary of re- 



Weakening suits of different methods of drying on the 



Effect of strength of wood. Over 2,000 mechanical 



Drying Wood tests were made on carefully selected and 



matched specimens of White ash, Red oak, 



and Loblolly pine, and 37 drying processes were employed. 



"Two general effects were noted : ( 1 ) that all processes used 

 in this research reduced the strength of the wood, when it was 

 resoaked and compared with the untreated green-soaked stan- 

 dard ; and (2) that the hygroscopicity was reduced by most of 

 the treatments and the color darkened, particularly in the higher 

 temperature treatments." 



Four tables of results are given, which reveal some very signi- 

 ficant comparisons. The weakening effect of steaming at high 

 temperature or for too long is clearly shown. The subjecting of 

 wood to high temperatures increased its brittleness when sub- 

 jected to impact. 



S. J. R. 



The Effect of Different Methods of Drying on the Strength of Wood. Lumber 

 World Review, April 15, 1915, pp. 19-20. 



This article describes the method of char- 



Manufacture coal burning followed in the Forest of Dean, 



of which is fairly typical of the practice of 



Charcoal English charcoal-burners. The usual size 



of kiln is 7 feet high, 18 feet in diameter, 



giving a capacity of about 8>4 cords. (A cord equals 128 (piled) 



cubic feet, or about 64 cubic feet solid of cordwood.) The 



weight of charcoal produced from oak has been found to be 



approximately 20 per cent of the weight of the wood used. 



The burning is usually given on contract at from 18 to 25.?. 

 per ton. The cost of the wood at the kiln is bs. per cord, so 

 that to the sum paid for labor about 15j. per ton of charcoal may 

 be added for the value of the wood. Besides labor, the only other 

 considerable items of expense are sacks for packing (40 to the ton, 

 but used several times), and cartage. 



Under normal conditions charcoal in large consignments sells 

 at from £2 to i2 10.r. per ton on rail, while for small quantities 

 (say 2 or 3 tons), such as are used for drying hops in the south 

 of England, as much as £4 per ton may be obtained. At the 



