726 Forestry Quarterly 



Betts had given the relative cost of the box and cup systems, in 

 addition to the data presented in Tables 9 to 13. Granting the 

 reputed financial advantage of using the cups, why is it that the 

 turpentine operators in Alabama use cups on but 8 per cent of the 

 trees, while, even in Texas, but 49 per cent of the resin is secured 

 by cupping? They show, unquestionably, a better yield from the 

 use of cups, but what is the relative expense in working, and for 

 installation — and the resiilting net profits ? It is unfortunate that 

 Bulletin 229 does not answer this question. The bulletin is re- 

 markable in its excellent description of methods, machinery, and 

 in its accumulation of data which must prove of value to the tur- 

 pentine operator. It appears, however, somewhat weak in the 

 presentation and description of French tapping methods, and in 

 the results of the experiments undertaken by the Forest Service 

 during the past 10 years. As the authors admit, there is much 

 to be answered; some of the most important questions cover 

 problems which the operator must know and understand before 

 he will make the effort to revolutionize the antiquated methods 

 of the past half century. For example, in Table 14, page 25, 

 the results of different methods of chipping are given. These 

 figures, however, are disappointing, since the results are not based 

 on a fixed factor, or unit of comparison (as, for example, per 

 square inch of face for trees of different sizes, soils, and varying 

 producing capacities). The results are of interest, but by no 

 means conclusive, simply because the experiments were not 

 scientifically planned and elaborated. (See footnote p. 35 of 

 bulletin.) 



Beginning on p. 32, the authors review the French methods 

 of collecting gum. A French forester might question the exactness 

 of some of the data presented. For example, take the statement: 

 "The forest rotation varies from 60 to 75 years." The authors 

 should have stated that rotations higher than 75 years, however, 

 are frequently met in the Landes; e. g., in the Forest of Mimizan 

 it is 80 years; it is also 80 years in the Forest of Saint-Julien-en- 

 Born. It is hardly correct to say that the French " lop " the lower 

 branches, since they are more properly described as pruned. 

 "The wood resin rights are sold for a period of 5 years," to be sure, 

 but also for periods of 4 years, as is indicated in the translation 

 given on p. 34, fourth paragraph, where the official instructions 

 state: ". . ,. if the tapping period is for four years." As a 



