730 Forestry Quarterly 



visability of tapping such stands can be granted. The tapping of 

 Corsican {Pinus laricio) pine in Corsica was not a success silvi- 

 culturally. What would the danger from insect or fungus at- 

 tacks amount to in Arizona or New Mexico? The writers seem 

 to be somewhat in doubt as to the future success of Western tur- 

 pentine operations, for, on p. 46, they state: "The commercial 

 success of turpentine operations in the Southwest will be doubtful 

 until tried on a commercial scale," but, a few lines farther on, they 

 say: ". . . make it reasonable to suppose that turpentine 

 operations in the large tracts of virgin pine timber in the West 

 will in time be justified." 



The data on evaporation from cups (p. 47), comparison of yields 

 from north and south faces, effect of temperature on weekly yield 

 of gum, rate of flow during week, are of great interest and value. 



A careful study of this bulletin, as well as of French works on 

 turpentining, shows that there is much scientific investigation 

 to be done before the best methods of turpentining operations are 

 definitely known. To be conclusive, these experiments must be 

 upon a scientific basis instead of being based on the hit-or-miss 

 methods used in the past. Such investigations are urgently needed. 



The main difference between tapping methods in France and 

 America seems to be in the width and annual increase in height of 

 the face. In the United States, the first streak cannot begin 

 higher than 10 inches above the ground. In France, it can be 

 anywhere above the root swelling. In America, the maximum 

 depth of streak is .5 inch ; in France it is approximately .4 inch. In 

 America, in Federal tapping operations no tree less than 10 inches 

 can be tapped and trees 16 inches and over can have two faces, 

 while trees 10 to 16 inches can have but one face. In France, the 

 minimimi diameter of tree tapped on State forests (unless to be 

 removed in thinnings) is 13 inches and the number of faces is 

 specially designated by the Waters and Forests Agent. In the 

 United States, the face can be 12 to 14 inches wide with no specified 

 decrease in width as the face proceeds up the tree. In France 

 (according to the former system as described by authors) , the width 

 is 3.5 to 2.4 inches, decreasing each year as the distance above 

 the ground increases. The maximum height increase per year in 

 the United States is 16 inches, while in France the face can be 

 lengthened 24 to 26 inches, and even up to 39 inches in case of 

 four-year tappings. (See table of revised dimensions in this re- 



