60 PROPERTIES OF WOOD. 



wood of other pines, which they compared with that of the 

 Weymouth pine, such as P. resinosa, P. divaricata (Banltsiana), 

 P. rigida, P. ponderosa ; we should not accept their judg- 

 ment blindly, as it can be proved from mature Europe-grown 

 wood only of these species, which can then be compared 

 commercially with our own pine wood. 



A third error arises from comparing the wood of young and 

 old trees of the same indigenous or exotic species. Young 

 conifers, e.g., Weymouth pine, necessarily contain poor wood, 

 for either they have no heartwood or very little in proportion 

 to their sapwood, while their lower branches have not fallen, 

 or their knots are covered with a few zones of wood only. The 

 older the Weymouth pine is, when grown in Germany, the 

 more favourable are the opinions held about the quality of its 

 wood. It is this opinion, and not that of Americans, that is 

 decisive for us. 



(7) The soil under similar climatic conditions greatly 

 affects the width of the annual zones and the weight of wood. 

 Hartig has, however, stated that soil has no influence on 

 beechwood,.but that the best soil produces the heaviest spruce- 

 wood.* It is certain that every species of tree finds he most 

 favourable conditions for its growth on the best soil. It 

 strives to form a large crown and a tall bole, so as to ensure 

 its fructification. In forestry, however, the vegetative part of 

 the tree, the bole, is more valuable than the fructification, 

 and should be as free from knots, as rich in heartwood, and as 

 cylindrical as possible. These requirements are not secured 

 always on the absolutely best soil. Such is a well-manured 

 garden soil, and wood grown on such a soil is branchy, broad - 

 ringed, and may suffer from red-rot. Also on very poor, dry 

 soil wood grows slowly, with narrow zones, and is less heavy 

 than wood produced on moist, loamy sand or sandy loam. 

 Hence for every species there is a soil optimum that yields 

 the heaviest wood, climatic conditions being equal, and soils 

 richer or poorer in nitrogen than the optimum yield wood of 

 lower sp. weight. 



(8) When sapwood passes into coloured heartwood, the 



* R. Hartig, "Ban u. Gewicht ties Fichtenholz." Forstlichc Natunv. Zeit- 

 schrift VII. 1898. 



