142 SCIENCE IN FORESTRY 



start new plantations by planting the young trees 

 very close together, often at intervals of three feet 

 or less. In continuation of the same principle, 

 the plantations have often been insufficiently 

 thinned. It is already proved that close planting 

 gives a smaller yield of timber than moderately 

 wide planting, while it costs a great deal more. 

 Further, without investigation we do not know to 

 what degree and at what periods thinnings should 

 be carried out. Ocular impressions of the condi- 

 tion of things are wholly misleading, as the present 

 condition of any immature wood is only of import- 

 ance in so far as it affects the final yield. Hence 

 more exact methods have to be employed, and it is 

 surprising to what extent forestry has already 

 become mathematical. The tree and the forest 

 have been analysed, and the relationship of the 

 contents at any period to the contents at subse- 

 quent periods can be seen, and thus the result of 

 any operation on the subsequent life of the forest 

 can be predicted. 



Forestry does not aim at merely producing wood 

 but must produce wood of the desired quality. 

 Hence the branch of science, which is known as 

 "Timber Physics," has a distinct bearing on the 

 forester's work. Knowledge of the relationship of 

 the growing conditions to the quality and technical 

 characteristics of the wood produced, would enable 

 the forester to proceed intelligently in his work, 

 and to some extent to control the quality of the 



