196 THE THEORY AND PRACTICE OF WORKING PLANS 



versely it is diminished. Hence, a careful exposition of the 

 age-class distribution is of vital importance. 



The Saxon system, of maximum money returns on the invest- 

 ment, demands that those stands whose index per cent is lowest 

 be cut first. The next most important consideration is the cut- 

 ting series; for with the preponderance of spruce, the danger 

 from windfall demands that the cutting areas progress toward 

 the prevailing wind direction. Since the cutting strips are 

 narrow and an interval elapses before the adjacent strip is cut, 

 it follows, as a general rule, that the cutting series are short. 

 However, in order to accomplish this and to avoid the joining 

 together of large areas of practically equal age, it is necessary 

 to have many points of attack. To secure these, the edge of a 

 stand exposed by the removal of the sheltering stand to wind- 

 ward, must betimes be accustomed to the exposure by the for- 

 mation of deep crowns^the so-called forest mantle or wind 

 mantle. 



The most important task of the forest organization, as re- 

 gards arrangement of area, is the selection of these points of 

 attack for the cutting series. The further development of the 

 cutting series can, however, be only sketched, since it depends 

 on circumstances which the organizer at the time of drawing up 

 the plan cannot know. 



The volume of the cut for the working period of ten years 

 is found by ocular determination of the stand on the area to be 

 cut over. The cut to be expected from thinnings is gauged 

 according to the results of the decade past, aided by yield 

 tables, and, of course, with special regard to the needs of the 

 stands. 



Stress is laid on the continuity of statistical records in re 

 age-class distribution, volume of growing stock, yearly cuts in 

 amount and classes of material, the gross income, the expenses, 

 the net income (Reinertrag) , the forest capital, etc. These 

 records have been kept in Saxony since 1817 and are invaluable 

 aids for purposes cf forest organization. 



In addition to the revisions at the end of the ten-year work- 



