Periodical Literature 397 



There is no difference in principle in these two calculations, 

 and there should be no difference of results by either method. The 

 latter is, however, simpler. 



The fundamental formulae are 



Fr.OX = fr 



whenF= forest value, / = forest rent, from which, subtracting the 



one from the other, the per cent is developed x=l(^^^ ~\ 



Fr+\-Fr 



an index per cent to be used similar to Pressler's. But, since in 

 this case the ideal forest of stands of equal areas and equal quality 

 is posited, in the expression Fy^i — Fr all stand values from the 

 age class o to r — 1 with their soil values may be excluded as of no 

 consequence in the difference, and hence merely the value of the 

 last age class, the r year stand, and the last member of the forest 

 value Fr+i, is needed — an easily ascertained tangible sale value. 



The author then critically reviews the formulae of Pressler, 

 Schiffel, Riebel and others and shows that their error lies in the 

 fact (inherent in the soil rent theory) that the soil alone is charged 

 with all expenses, the stock of the management class being uncon- 

 sidered in this theory. 



The argument in developing his own f ormxila is as follows : The 

 value of an ideal management class under a rotation (r) shows r 

 parts, the combined effect of which produces the annual forest 



rent /,. Hence the forest value -^-^ should be distributable over 



.op 



fr I.OP'-I 



r parts. If we write this forest value :;^ } — 7 X ;: — ,the 



^ l.op —1, .op 



last factor represents the sum of the r parts: l.op''-\-l.op^-\-l.op^-\- 



. . . 4-l-op'^~^+l-0:/''^~S and if the r times repeated value ^ — 



l.op — 1 



is called K, then 



F,= ^ ^: -X ^'""^ ~^ =Kl.op'+Kl.op'+l.op' + . . . +1V' 

 l.op — 1 .op 



-\-l.op'^~\ the forest value in r parts. 



