196 



FARM FORESTRY 



are often weighted down or clamped to prevent their warping 

 in drying. 



Toughness. A property desired in many woods that are 

 subject to sudden shocks so that they will recover from 

 them is toughness. The rims and spokes of a wagon are 

 subject to many sharp blows in every mile, an ax handle 

 is jarred with every stroke, a trunk must stand many bumps 

 and blows in the course of a journey. A wood that shatters 

 easily or that breaks instead of resisting a blow will not serve 

 these purposes. A tough wood must be strong and pliable 

 and not weak and brittle. Basswood, hickory and ash are 

 examples of tough woods. 



Fuel Value of Woods. In general the heavier the wood 

 the greater will be its fuel value. All woods do not burn in 

 the same way. Chestnut, larch and hemlock crack in the fire 

 and emit sparks, while hornbeam, birch and alder burn with 

 a particularly quiet flame. With coniferous woods the larger 

 the quantity of resinous material in the wood, other things 

 being equal, the greater the fuel value. Fat pine or light 

 wood is wood that has a large amount of resinous material. 

 Dry woods burn much better than wet woods and send out 

 more heat. This is because with wet woods much of the heat 

 will go to evaporate the moisture in the wood. It is claimed 

 that 5.2 pounds of dry wood is equivalent in the amount of 

 heat produced to one pound of hard coal. 



TABLE OF FUEL VALUE or COMMON WOODS 



Color. Color adds to the value of wood for decorative 

 purposes and is an aid in identifying woods. The color of 



