268 METHODS OF TIMBER ESTIMATING 



used contains 40 acres. Even here fractional lots lying along the north 

 and west boundaries of a township or adjoining meandered streams 

 and lakes call for a plot which shows their dimensions. With these 

 rectangular areas it is a simple matter to obtain a definite per cent of 

 the total by running strips of a given width. 



On irregular tracts, a map showing the boundaries and area is 

 required to enable the cruiser to determine, first, in what direction and 

 relation to lay out his lines or strips, and second, to compute the exact 

 per cent of the total. This desired per cent is approximated and the 

 exact relation secured is determined after the lines are run. 



214. The Forest Survey as Distinguished from Timber Estimating. 

 Timber estimating may be undertaken for the sole purpose of determin- 

 ing the volume of timber on a tract, but as commonly carried out, this 

 requires the running of numerous definitely located compass courses, 

 gridironing the area, which gives an opportunity for the collection 

 of a large amount of additional data required in its permanent manage- 

 ment and in the logging of the area. The collection of this additional 

 data, together with the timber estimate, constitute what is termed a 

 forest survey. Even the crudest work of timber cruisers embraces 

 some elements of a forest survey. The features of such a survey are: 



1. A map showing the topography of the area either by hachures 

 or contours, giving streams and ridges and other important features 

 which influence logging and management. 



2. A map showing the character of the forest cover, classified as to 



(a) Timber types, corresponding with divisions made in the 

 stand in timber estimating and showing blank areas, such 

 as water, barren, cultivated or grass-land. 



(Jo) Divisions due to age of the timber such as burns, re-stocked 

 or barren, reproduction or immature timl)er, older age 

 classes. 



3. Soil maps, locating land of agricultural value and land fit only 

 for forest purposes. 



Under timber estimating proper, the forest survey makes an inven- 

 tory showing both the quantity and quality of timber by different 

 products, grades and sizes as required for the purpose of valuing the 

 tract as follows: 



1. Quantity or volume. 



(a) Separately by species. 



(6) Separately by units of merchantable volume, as board feet, 



poles, cords, 

 (c) Separately by character, as live or dead timber, sound or 



cull, and giving the net volume after deductions for cull. 



