Volume Tables. 9 



variation in form from or towards the cylindrical would be well 

 expressed by the relation between two diameters properly chosen 

 at different points on the stem is equall}- evident. The breast- 

 high diameter has been universally chosen as the most practical 

 point at which to measure the diameter of standing trees. Schu- 

 berg found from a very careful study of 1352 trees that the middle 

 point was the most critical point on the stem for a second measure- 



meut. This relationship then between ^ and 8 (or X 100 to 



d 



express it as a per cent.) is capable of expressing any variation in 

 form due to any factor or combination of factors, such as site, age, 

 or silvicultural conditions. 



In the same year Kunze ^ published the results of a very 

 thorough study of the form of the stems of the Norway Spruce 

 and Scotch Pine with regard to this relationship of d to S. Some 

 10,000 spruce and over 8,000 pines were carefully measured, but 

 aside from demonstrating the entire practibility of utilizing this 

 factor in determining the form factor (/") of stems, Kunze failed 

 to suggest any important practical application. 



It remained for Schiffel ^ to develop this idea further, and in 

 1899 he published his volume tables for the Norway Spruce based 



on height and diameter classes and the — relationship. His 



d 



tables were developed from data obtained by the careful section- 

 ing of 2,529 trees, in all of which he made a special note of the 

 relationship between the diameter at breast-high and that at yl 

 and ^ height as well as that at )4. height (S). He finally con- 

 cluded that while the ^ height diameter could be safely utilized 

 when from any cause the diameter at ^ height could not be 

 measured (obscured by branches, etc.), but that, on the whole, 

 the diameter at ^ height was the most generally satisfactory. 

 In this his work is in entire accord with that of Schuberg already 

 noted. 



Schiffel has termed the factor which expresses the percentage 

 relationship between the diameter at breast-high and that at yi 



height ( —r X 100 I \\\Qform quotient, and as the expression 



^ Neue Methode z. raschen Berechnung d. unachten Schaftformzahlen d. 

 Fichte u. Kiefer, Dresden, 1891. 



^Fonn und Inhalt der Fichte, Mittheilungen a. d. Forstversuchswesen 

 Oesterreichs, Wien, 1899. 



