ROTATION OP GREATEST VOLUME PRODUCTION. 209 



Let volume of final yield be = F r 

 Volume of thinning in the year a = v a 



, > b = v b 



etc., 



<1 = V q 



then the rotation of the greatest production is that in which 



the value r ' becomes a maximum. 



f 



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

 timber only. 



Example. Taking the data for total yield in the table 

 at page 189, for timber only, the rotation of the greatest pro- 

 duction would fall about into the year 80, which is approxi- 

 mately the financial rotation. 



For timber and firewood (page 191) 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 Technical 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, telegraph 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 difference between the technical and financial 

 rotations. 



5. The Physical Rotation. 



By the physical rotation is understood that age which 

 is most favourable for the natural regeneration of a species, 

 taking into consideration the conditions of the locality and the 

 sylvicultural system. It cannot be lower, in the case of high 



VOL. III. ' P 



