204 



THE FORM OF TREES AND TAPER TABLES 



be obviated by the printing and general distribution of the graphs 

 giving the average form, from which tables could be prepared in the 

 office for whatever use was desired. 



169. Limitations of Taper Tables. The real weakness in this 

 apparently sound method of preparing the basis for volume tables lies 

 in the fact that the i-esult obtained does not differentiate form classes 

 of trees, but averages them on exactly the same basis as do the standard 

 volume tables. Its only merit therefore is in the transferring of records 



24 



32 40 48 56 & 



Height above Stump, Feet 



Fig. 35. — Tapers read from Fig. 33 for four diameter classes, showing effect of har- 

 monized curves in smoothing out the irregularities of form shown in Fig. 32. 



Similar curves are obtained from tapers replotted inform of Fig. 33 frojn curves 

 shown in Fig. 34. Such tapers will be harmonized by diameter and height 



of average tree forms to the office as a basis for future volume tables. 

 The form of the tables is bulky and does not lend itself to the further 

 extension necessary to show the form of trees of several different form 

 classes for each diameter and height class, though in the preparation 

 of standard volume tables by the U. S. Forest Service, such taper tables 

 have been extensively employed. The use of taper tables in connec- 

 tion with standard form classes as a basis for universal volume tables 

 is discussed in Chapter XVI. 



By preparing separate sets of taper tables for each form class based 

 on absolute or normal form of trees (§ 174) a permanent basic standard 

 of tree form is obtained which will fill all possible future requirements. 



