SYSTEMATIC FORESTRY 107 



of those sciences which prove the truth of the 

 practical rules of the art of forestry. 



Some writers claim that a forester ought to 

 make himself acquainted with those sciences 

 which establish the truth of the practical rules 

 of forestry. Unfortunately for this extension 

 of knowledge, the charge of English woods can 

 as a rule claim only a very limited portion of 

 a man's time, and in the more fortunate cases, 

 where forestry is a man's sole profession, he 

 can learn only very little of these sciences, 

 however great his leisure and ability may be. 



Nothing can be gained by attempting to place 

 upon foresters such a burden of universal and 

 profound learning that the very enumeration of 

 its kinds is enough to frighten them.^ 



Common sense must decide what can be 

 learnt. For example, a study of botany might 

 require more time than a practical forester 

 might be able to give, but a knowledge of the 

 common plants and flowers might be acquired 

 without much difficulty and usefully. 



In almost all cases the practical rules are 

 successful, and it is not necessary to go behind 



* Sir Joshua Reynolds, Discourses, No. VII, and J. S. Mill, 

 Logic, book vi., chap, xi., "Relation between rules of art and the 

 theorems of the corresponding science." 



