270 METHODS OF TIMBER ESTIMATING 



3. Economic conditions, markets and prices for lumber. 



4. General appraisal, cost of milling, cost of logging, cost of trans- 

 portation, profits required. 



5. Specific appraisal, the direct cost of logging the specific body 

 of timber and the resultant stumpage value of this unit. 



A clear-cut distinction between the work of timber estimating and 

 of timber appraisal will prevent the mistake so often made of burden- 

 ing the timber estimating crew with the work of recording in great 

 detail items of cover, surface, brush, etc., which instead should be sum- 

 marized for an entire unit by the person who appraises the value of the 

 timber and sizes up logging conditions. It is seldom that the two jobs 

 can be effectively combined in the same party or individual. The 

 work of timber estimating requires routine and concentration on the 

 details of the job. The actual appraisal, even if the same party makes 

 it, should follow rather than accompany the estimate a"nd should be 

 based first, upon the data on topography as shown by the map and 

 second, upon the data on volumes as shown in the estimate. 



216. Forest Surveying as a Part of the Forest Survey. A forest 

 survey as above outlined includes the work of forest surveying or the 

 determination of the boundaries and area and the mapping of the topog- 

 raphy of a forest tract. This subject is not a part of Forest Mensu- 

 ration, but must be treated separately. Since the gridironing of the 

 tract requires the measurement of distance and direction and the plotting 

 of these lines will give the framework of a map, it follows that the work 

 of making a topographic map which may employ the same general 

 methods of examination for the area, can be advantageously combined 

 with the work of timber estimating. Timber cruisers usually prepare 

 a crude map showing the intersection of streams and the position of 

 ridges and other topographic features of importance. The prepara- 

 tion of a map based upon basal elevations and giving contours is a 

 development of the timber survey introduced by foresters and adds 

 ■ greatly to the efficiency of the survey. By combining this map-making 

 with the entirely separate operation of estimating, a crew of two men 

 can complete both operations with a very slight increase in expense, 

 not comparable with the cost of doing each piece of work separately. 



At the same time the preparation of the type or timber-cover map 

 can proceed, and upon this in many instances depends the accuracy 

 of the timber estimate itself (§ 225). * 



1 The detailed methods of Forest Surveying employed in a forest survey cannot 

 be discussed in a text on Forest Mensuration without exceeding the limits of the 

 volume. Any summary of a system of forest survey must include a description 

 of the methods of surveying and topographic mapping which are to be used. The 

 various methods of survey must be co-ordinated with the methods of cruising and 

 with the cost and relative accuracy of the work desired, both for the survey and 

 the estimate. 



