584 JOURNAL OF FORESTRY 



height cruising. It would also make it possible to assume any intensity 

 of utilization that is desired, i. e., to have a graduated top diameter 

 limit. It would make it necessary to have but one base table for the 

 whole country. The intensity of the utilization would be allowed for 

 in the form factor and could be changed to suit conditions without 

 changing the base table or the standard of height measurement. A 

 cylinder could be used as well as a cone for the basis of comparison 

 and it would be easier to compute its volume in board feet. 



That Bruce's method, which perhaps may revolutionize our method 

 of volume table preparation, should have been introduced to American 

 foresters so recently, as the result of one man's study, is striking 

 evidence of the possibilities that lie before the investigator in the 

 realm of forest mensuration. 



A UNIVERSAI, VOLUMK TABLE 



Foresters who have a dozen or so species of trees, for each of 

 which a separate volume table must be used on a single cruising job, 

 have long wished that there might be a universal volume table, i. e., a 

 table which would fit all species everywhere. Perhaps it is Utopian to 

 even hope to get one which can be used in National Forest cruising, 

 but yet who knows what further investigation will bring forth. The 

 Lacey volume tables and Schenck's cruiser tables, already spoken of, 

 are truly universal tables, but since one is based on three, and the other 

 on four, variables, I do not believe they are usable when the individual 

 trees are tallied by species. 



Bruce has pointed out that the frustum-of-cones-base table can 

 be used as a universal table by applying correction factors for each 

 species. These correction factors are the frustum form factors them- 

 selves. Theoretically the frustum form factor varies for each diameter, 

 but tests have shown that an average flat factor for all sizes can be 

 applied with only slight chance of error. By this method the tally of 

 each species can be worked up by the one table and then a species form 

 factor can be applied as a correction. Some little saving of time in 

 volume table preparation, but none in the mechanical office work of 

 a timber survey project, can be effected by this method. 



Prof. Chapman says,^ after a discussion of the possibilities of 

 making a universal table, "Where trees differ in form, in degree of 

 utilization, and in standard of board foot measure applied to their 



Proceedings Society of American Foresters, Vol. XI, No. 2, p. 191. 



