FOREST SERVICE STUMPAGE APPRAISALS 713 



run values thus secured are more reliable and more accurate for use in 

 appraisals than would be any estimates based on available data. The 

 Office of Products conducted a mill-scale study during 191 3 at 10 dif- 

 ferent hand mills scattered throughout the Inland Empire region. 

 More than 12,000 logs of various species were recorded. Accurate 

 data were secured on the percentage of grades which timber cut in dif- 

 ferent parts of the region would produce and on the percentage of 

 overrun lumber tally over log scale, as determined by the Scribner 

 Decimal C Scale Rule' for different species. 



The mill-scale study data are sometimes used as a basis from which 

 to figure the percentage of grades. This is done in cases where a check 

 on the lumber values as reported by the Lumbermen's Information 

 Bureau is desired or the timber is of unusually good or poor quality. 

 The data secured by the mill-scale study on overrun are used in all ap- 

 praisals. The overrun is based on No. 5 common and better. The 

 table showing weighted overrun and one giving the average mill-run 

 value of timber f. o. b. the cars from 1913 to 1916 indicates the form 

 in which these important factors are made available. 



The Timber Survey organization does the estimating and mapping 

 on all large projects. Intensive timber surveys are made, after areas 

 have been covered by an extensive examination to collect data concern- 

 ing the stand of timber in general, the feasibility of logging, and the 

 desirability of making a sale. The most logical logging units in locali- 

 ties where there is a demand and real need for the timber are covered 

 first. 



The appraisal work begins where the timber-survey work ends. The 

 standard for timber surveys requires that 10 per cent of the area of 

 merchantable timber shall be covered, all cruise lines chained, eleva- 

 tions carried with an abney level, and topographic maps made, using a 

 contour interval of 25 feet to 50 feet or 100 feet, as the topography 

 may require. This method of cruising, and of mapping especially, has 

 proved to be of great value to the appraisers. The maps are accurate, 

 and it is often possible to determine from the detailed topographic data 

 which are furnished the most feasible method of operation before going 

 in the field. 



FIELD METHODS 



Appraisals are made after there has been a definite application for 

 the timber.- In large drainages or chances covering several sections 



'On the Coeur d'Alene Forest appraisals are made of the bodies of timber 

 ^vhich the Forest Service wishes to sell without awaiting specific application, 

 since practically every chance is salable. 



