22 THE THEORY AND PRACTICE OF WORKING PLANS 



sketched in from aneroid barometer traverses.* In level country- 

 contours serve no useful purpose. In the matter of topography 

 the object is to get a good working medium for orientation and 

 for the subsequent division of the area. 



The scale of the map must depend on the size of the area, 

 the wealth of detail, and the intensity of the proposed manage- 

 ment. Ordinarily a scale of i or 2 inches to the mile for the 

 general map is quite sufficient. Where the forest is very large 

 it is well to have a small scale location map, and then larger 

 scale maps showing the various parts of the forest in greater 

 detail. 



No survey of the area — and no forest map — is complete 

 which does not include a delineation of the forest types. This 

 is usually done in conjunction with the estimating, but its 

 importance must be emphasized here. Simplicity in type 

 distinctions is essential for clearness. Only those type differ- 

 ences should be recognized which are sufficiently striking to 

 be recognized instantly by every trained eye. Ordinarily, per- 

 manent types alone should be regarded, but often transitory 

 types — e.g., aspen on old burns — must be recognized, since they 

 demand a different treatment. Minor differences should never, 

 for the purposes of a working plan, be made the basis of type 

 distinction. 



The mapping of all cut-over or burned areas, of swamps, 

 barrens, etc., is a part of every forest survey. 



Timber Estimates 



Requisites. — Without encroaching on the subject of forest 

 mensuration, the requisites of the timber estimates for purposes 

 of the working plan are: 



1. Amount and species of timber. 



2. Class of timber (saw timber, cordwood, etc.). 



* The topographers of reconnaissance parties of the U. S. Forest Service 

 prefer the Abney hand level to the barometer for any work except the making of 

 very rough maps. See " The Abney Hand Level and the Chain on Intensive 

 Forest Surveys," C. R. Anderson, For. Quart., Vol. XIII, No. 3, pp. 338-343. 



