THE THEORY AND PRACTICE OF WORKING PLANS 191 



tions of the plan. Often, however, it sufitices in such cases to 

 make provisional changes for the remainder of the working 

 period. Natural calamities — wind, fire, etc. — always require 

 some time before the measure of the catastrophe can be prop- 

 erly judged. 



The intermediate revisions are to cover the following points: 

 a. Necessary corrections of the methods of determining the 

 cut (checking of estimates, etc.). 



h. Determination of the cutting areas for the past decade, 

 comparison with the allowed area, and determination of the 

 area for the ensuing decade which again is really that for a 

 period of twenty years. 



c. Emendation of the plan of management. 



d. Determination of the volume yield of the next working 

 period (based on a, b, and c). 



e. The making of a new map of the forest. 



In the main revisions the task is a similar one, but more 

 exhaustive. The results of the management during the past 

 period — twenty years — are to be compiled and the whole 

 structure of the working plan renewed as may be necessary. 



Bavaria, in common with many of the German States,* has 

 a separate section of working plans in the central office at 

 Munich. This section is charged with the field-work and the 

 office preparation of the plans. The supervisor of the forest 

 concerned is consulted in every feature of the plan; he and his 

 subordinates are charged to assist in the preparation thereof. 



The bases of the plan as well as the completed plan require 

 the approval of the royal ministry of finance, forest section. 



The procedure in working plans is as follows: 



During the working period the supervisor is supposed to 

 keep careful record of such results of management as aid in 

 judging of the volume and value yield. The underlying field 

 data can often be supplemented by him during slack periods of 

 the year. 



* E.g., Saxony, Baden and Wiirttemberg; Prussia is a notable exception. 



