2 



The study of the principles of Exploitability, altogether pecroliar 

 to forests, and so important and difficult besides, has seemed to us to 

 require some further development suggested to us by the condition of 

 our forests, which is growing every day more and more precarious in 

 the times in which we live. To speak truly, there are only two different 

 classes of circumstances under which forests are exploited ; either 

 they are utilised when mature like all other fruits of the earth in 

 general, or they are cut prematurely as a speculation in view of 

 securing a high rate of interest on capital expended. In order to 

 render this idea clear, we have adopted the term Economic Exploita- 

 bility to express the state of a forest worked under the first class of 

 circumstances, because they are in strict conformity with the general 

 economy of the State or the public good. This Exploitability, as we 

 shall see, comprises, according to the results sought, or to the cir- 

 cumstances under ivhich it is applied, (1) the " Exploitabilite 

 absolue" of the " Course of Forest Culture," (2) the Exploitability 

 relative to the most useful produce, which may be more simply 

 termed Qualitative Exploitability, because it furnishes the most use- 

 ful ligneous products employed in the arts and manufactures, and (S) 

 National Exploitability, suitable for adoption in blocks of regular 

 high forest. In the same manner we have adopted the term " Com- 

 mercial Exploitability," to denote, as opposed to Economic Exploita- 

 bility, the circumstances under which a forest is worked with a view 

 to obtaining the highest possible rate of interest on capital invested. 

 In this respect, what is far more important than mere words, are- 

 principles. In France these latter have always remained the same^ 

 and it is interesting to note here that at the French Forest School 

 the fundamental principles on which the working of forests rests> 

 viz. Natural Regeneration and the Most Useful Production: 

 have never been questioned. 



The Second Book, which treats of the operations common to 

 all Forest Organisation, explains in the first place how to set about 

 in order to study a given forest, by dividing it into compartments 

 and then describing each of these compartments and drawing up the , 

 statistics of the forest. It gives in the second place the rules to 

 observe in forming Working Circles, which are' perfectly independent 

 portions of one and the same forest. Next it describes the special 

 procedure to follow in order to determine, in the various cases that 

 may occur, the rotation or age at which the standing crops should 

 be cut. Lastly, this Book ends with an expos^ of the circumstances 

 which regulate the order to be observed iu the exploitations. 



