no 



TECHNICAL QUALITIES OF THE TREES 



(b) Nail holding power, which is said to be excellent in hemlock. 



Experiments described in Engineering News, January 10, 1894, claim the followintr ratio of tenacity 

 of 6d nails. 



The figures represent resistance to pulling in lbs. offered per square inch of nail surface. 



(c) Twisted growth, which is frequent in chestnut, chestnut oak, Lombardy poplar, and horse 

 chestnut. Certain twists are due to a hypertrophical growth of the tissue and are highly prized by the 

 trade under the names of birdseye maple, curly poplar, curly walnut, curly cherry, curly ash, <&c. It is 

 often impossible to say whether a standing tree is "curly" or not. Sap-sucking woodpeckers may start 

 the "freak." 



(d) Knots check the value of lumber. A standard knot is a knot, the diameter of which varies 

 according to inspection from l\U inches (hardwoods) to I'A inches (shortleaf pine). Usually the knotty 

 part of a log is sawn into dimension stuff (boxed heart). The core of a log, necessarily, shows knots, since 

 there is no height growth without simultaneous formation of side branches. 



(e) The discoloration of the inner layers of certain species (beech, maple) which resembles heart- 

 wood is a disease often found in old trees and causes rejection for certain applications in the trades 

 (impregnation). 



Logging scene in the mountains of Saxony, a country 



where conservative forestry pays its way. 



