66 Germany. 
He divides into proportional areas (which were 
marked by stones in the woods) equalizing them accord- 
ing to age, quality, accretion, soil, exposure, so as to 
secure equal annual budgets ; the stands were ranged into 
seven or eight unequal age classes and each into as many 
annual felling areas as there are years in the age class; 
if some of the age classes were absent, he cut in the older 
class until the younger had grown to the proper age and 
by varying the cut from good to poor sites or stands he 
tried to even out the budgets. The volume budget he 
determined by average accretion measurements. This 
method was however much too far advanced and required 
too much mathematics to find imitators at that time. 
Another method which proved also too complex for 
the foresters of the time was that of v. Wedell; neverthe- 
less, by 1790 he had put into working order 800,000 
acres in Silesia. He divided this area into districts, the 
districts into blocks or management classes and used an 
elaborated proportional area division for determining 
the felling budget. He distinguished quality of stand 
and quality of site and made four site classes. The 
volume of stock he found by means of sample areas, to 
which he added the accretion in order to find the total 
volume for harvest, when it could be determined how 
long with a given budget the stands would last, or what 
average annual felling budget could be taken before the 
next age-class would be mature. 
In the North German plain with very uniform condi- 
tions of soil and timber the method of equal felling areas 
was the most natural and most easily applied. 
Frederick the Great, who took a considerable interest 
in forestry matters, ordered such an area division in 
