140 UNITS OF MEASUREMENT FOR STANDING TIMBER 



Local log rules based on mill tallies may be substituted for the sawed 

 product as the basis of estimating timber on small tracts. 



No such difficulties affect the estimating of timber in terms of cubic 

 units or cords, which include the entire contents of all trees within the 

 merchantable limits of size, up to the merchantable limit in the tops. 



117. The Piece. Poles or piling usually comprise the entire mer- 

 chantable portion of the trees which produce them, but can only be 

 cut from trees having the specified dimensions. Familiarity with these 

 specifications enables the cruiser to count the number of pieces in the 

 stand, and to tally them in separate classes. The same method may 

 be used in estimating standard railroad ties, but in this case the number 

 of ties in each tree must be counted separately in accordance with the 

 five standard grades (Appendix B, § 369). Where the tree is large 

 enough to produce more than one standard tie from a single 8- or 8^- 

 foot length, the cruiser must rely either on his knowledge of the contents 

 of the bolt in ties, or refer to a volume table for piece products (§ 162). 

 He gets the total tie count for the tree by adding the contents of each 

 separate bolt, up to a point where the diameter is too small to produce 

 another standard tie. Posts are counted in the same way but, owing 

 to their smaller value and greater number, the count is usually more 

 or less of an approximation. The same system may be used, if required, 

 in estimating the quantity of mine timbers and mine ties in a stand. 

 Products such as stave bolts, which demand a high quality of timber 

 practically free from knots and all forms of defect, and are of small 

 size, introduce two features common to estimating in board-feet, namely, 

 a table of volumes, and discounts for cull. Stave timber for staves 

 of given sizes may be estimated by knowing how many staves may 

 be cut from bolts of given dimensions. The number and size of the 

 cuts in each tree will give their sound contents, from which are deducted 

 all visible defects. A liberal allowance is also made for invisible defepts 

 in the interior of the tree. 



Since only a portion of a stand is converted into these forms of 

 product, the estimating of piece products may be only a part of a 

 general estimate in which the remainder of the stand is measured 

 either for logs or for cordwood. 



118. Choice of Units in Estimating Timber. Methods of timber 

 estimating are determined by the cruiser's choice as to whether he will 

 deal directly with one of four units, namely, the stand as a Whole, the 

 individual tree, the individual log, or the piece (§117). Any one of 

 the first three methods may be used when the volume of the stand 

 is expressed in terms of cubic units, or in board feet. If the tree or 

 log is not used, the stand is considered as a whole and a direct guess 

 or estimate is made of its total contents (§ 206). If the tree or the log 



