OLEORESUST PEODUCTIOJST. 29 



considerable number of the outer sapwood rings are involved in the 

 jaelds of gum obtained is evident from the discussion on pages 9 

 and 10 and from Plate III, figure 2. 28 It would therefore appear 

 that the proportion of the sapwood which it is desirable to expose 

 in chipping probably varies somewhat according to circumstances, 

 and that the range of depth should be more exactly determined by 

 further experiments on different types of longleaf and slash pine 

 timber, especially on young timber, since this is of great future 

 significance. 



Crop C, the narrow chipping, did not have as narrow streaks as 

 those cut at Columbia, Miss. Although it was intended that the 

 streaks should be about one-fourth inch in height, it is stated that " in 

 spite of continued urging and the closest supervision, the chippers in- 

 variably made the cut wider than was desired. * * * Neverthe- 

 less in spite of the failure to reduce the width of the cut as much 

 as desired, a considerable decrease was made." The height of the 

 faces at the end of 4 years on crop A (standard) was 64.3 inches, 

 and on C, 50 inches, or an average height of chip of about 0.4 inch. 

 Under the narrowed chipping this crop showed an increase over the 

 standard which was greater than that secured by the shallow chip- 

 ping of crop B. Furthermore, less dry-face and dead trees resulted, 

 and about one year of chipping surface (14.3 inches) was gained. 

 These facts, therefore, furnish another instance of successful narrow 

 chipping. How far the streak can further be narrowed with ad- 

 vantage beyond this 0.40 inch and the 0.34 inch obtained at Columbia, 

 Miss., and sometimes obtained in commercial " pulling," is a subject 

 for further experiment. 



Crop D, the light cupping at Walkill, Fla., where fewer faces were 

 cut per tree and no tree under 10 inches was cupped, but where the 

 standard streak was cut, gave the highest yield of all the crops and 

 the least loss from dry-facing or death of trees. It should be borne 

 in mind that on the other crops trees with a diameter as small as 6 

 inches wen- cupped, and two laces were permitted per tree on timber 



th a diametec of 13 inches and over. (See Table 7.) As has been 

 recently shown, it is unprofitable from the point of view of the 

 growth in length and diameter of the timber, as well as from that of 

 th<- yield of guffl, to turpentine too small trees by the methods gen- 

 erally practiced in the Iniied States.-' (See Table 8,) 



It was demonstrated clearly both in the W^alkil) experiment and in 

 Cnry'r observations (Table 8) that it was of fundamental importance 

 to maintain the vitality and responsive power of the tree. Too large 



^tJiIh fad •■•■■•■ Dot recognized :>( the Mm<' that Che conclusion In regard u> simllow 

 dripping vu expressed In Pores! Service Bulletin 90 



* Cary, Austin, "A looh ahead " In Naval Stores, published by the Weekly Naval Stores 

 Review, and In "Money in actually lost In vvorkfng small treei for turpentine and i"Nin." 

 ,! stores lifvif-v. and Trade-Journal v..i v\x, jan, 22, 1021, p. 14, and Hot, 19, 

 10, 24, and 81, 1921, and Tan, 7 and 14, and B"eT>. i, 1022. 



