LONGLEAF PINE. 33 



of spirits of turpentine. (PI. X.) Both shallow and light chipping, 

 as practiced on the Florida National Forest, are effective in increas- 

 ing the yield of gum. 



6. If the yield for the first year is assumed to be 100 per cent, the 

 yields for the following years in per cents for a number of crops were 

 for turpentine 91.6, 70.6, and 62.2, and for rosin 93.8, 74.4, and 69.7, 

 respectively. 



7. If the total yield from three years' operation is assumed to be 

 100 per cent, turpentine operators count on obtaining about 45 per 

 cent the first year, 35 per cent the second, and 20 per cent the third 

 year. 



A publication of the Department of Agriculture entitled " Turpen- 

 tine, its sources, properties, uses, transportation, and marketing, with 

 recommended specifications" (Agriculture Bulletin 898, 1920), may 

 be obtained upon application to the Superintendent of Documents. 

 Government Printing Office, Washington, D. C. Price, 15 cents. 



EFFECT OF TURPENTINING TIMBER. 



It is generally recognized that turpentining longleaf as commonly 

 practiced renders the tree very liable to subsequent attack and in- 

 jury by insects and various fungi, to being felled by wind (PI. X), 

 and particularly to severe injury by fires. However, if turpentin- 

 ing operations have been carefully conducted by limiting the number 

 of faces per tree and the depth of Chipping, and if adequate protec- 

 tion has been given, the amount of timber in any way injuriously 

 affected has been shown to be very small; in one large operation in 

 central Alabama it was only about 1 per cent of the total stand. 



On the Florida National Forest a study was made, at the close of 

 the third year of working, of several sections of longleaf pine located 

 on private lands and adjoining portions of the National Forest. 

 There had been a severe drought during the working season imme- 

 diately preceding, and the casual observation of a marked difference 

 in losses of timber suggested the study. On the timber that had been 

 worked under Government regulations the losses were found to be 

 about 10 per cent of the total volume of timber, whereas on the pri- 

 vately operated timber losses were found ranging from 25 to 60 per 

 cent. Natural causes, such as insects, diseases, winds, and lightning, 

 were found to have produced about 4 per cent of the losses. Thus 

 the result of turpentining was. roundly, a loss of 6 per cent on Gov- 

 ernment-operated timber and from 20 to 55 per cent on private 

 workings. 



'1 he Mjffhanical properties of the wood are not affected by turpen- 

 tining operations. It may be of interest to know thai as far bach 

 as L895 this subject was studied and it was reported that tests and 



