80 Tan ADIRONDACK BLACK SPRUCE. 



But if there is to be no improvement cutting, if our forest 

 owners prefer to start with a fixed diameter as a basis for restric- 

 tion in revenue cutting "a rule of thumb," as Dr. Fernow calls 

 it such diameter can be fixed approximately in each locality ; 

 and when thus determined, if it approximates closely the average 

 diameter of the matured spruce, it may answer as a first step in a 

 right direction. Such diameter need not be fixed at the maxi- 

 mum. On the contrary, something should be subtracted to offset 

 what is termed in forestry the interest account. A perfectly 

 managed forest is one that will produce the greatest possible 

 revenue and maintain it. It is evident that as a tree approaches 

 maturity there comes a time in its slowly waning growth after 

 which the increment will not equal in value the interest on the 

 money obtainable if cut at that time. Before felling a tree it is 

 not necessary to wait for the signs of decay that announce the 

 cessation of growth. The tree may be turned into money before 

 that, and, in view of the interest account, thus yield a greater 

 profit than to wait for its maximum development. 



It would be impossible to name any diameters here which 

 should govern such cutting. But any owner of spruce lands can 

 arrive approximately at the proper size if the question is 

 approached intelligently and honestly. Ceri ainly, the twelve inch 

 limit now in use falls far below such requirements. A tree six- 

 teen inches in diameter yields twice as much lumber as one of 

 twelve inches ; and one twenty inches yields four times as much. 



By harvesting matured trees only, the land owner receives the 

 legitimate income from his property, and makes it a perpetual, 

 interest-bearing investment ; by harvesting the timber before it 

 attains its growth, he decreases the future productivity of his 

 land, and, for the sake of immediate returns, makes a heavy draft 

 upon the principal. Moreover, if he confines his cutting for 

 revenue to mature trees he not only preserves his principal intact, 

 but by adding to his work some judicious improvement cutting 

 he can increase the value of the principal and its corresponding 

 productivity. 



Many owners of spruce lands have been encouraged by the 

 repeated crops attainable from cutting on a basis of ten or twelve 

 inches in diameter on the stump to assume that such returns may 

 be obtained perpetually. Even if this could be done the yield 



