THE TECHNICAL ROTATION. 203 



3. Rotafiou of the Greatest Production of Volume. 



This is the rotation, under which a forest yields the greatest 

 quantity of material per unit of area ; it coincides with the 

 year, in which the mean annual volume increment culminates. 



Let volume of final yield = F,. 

 Volume of thinning in the year a = r„ 



„ " b = n 



etc., 



then the rotation of the greatest production is that, in which 



the value - ''"'"'" ' ^'' "^ ' ' ' ^^ hecomes a maximum. 

 r 



The calculation can be made for timber and firewood, or for 

 timber only. 



Example. — Taking, for instance, the data for total yield in 

 the table for Scotch pine medium quality, at page 364, for 

 timber only, the rotation of the greatest production would fall 

 al)out into the year 80, which is approximately the financial 

 rotation. For timber and firewood, the rotation would fall 

 into the year 60, which is considerably below the financial 

 rotation ; in this case a financial loss would be incurred. 



4. The Techmeal Rotation. 



By this is understood the rotation, under which a forest 

 yields the most suitable material for a certain fixed purpose ; 

 for instance, for construction generally, shipbuilding, railway 

 sleepers, telegrapli or hop poles, mining props, tanning bark, 

 fuel, etc. 



As the objects of management and the purposes, for which 

 the material is required, differ very much, the technical rota- 

 tion may fall into any age, either before, after, or into the age 

 of the financial rotation. The loss occasioned by following it 

 depends on the difterence between the technical and financial 

 rotations. 



