20 



WESTERN PINES AS A SOUECE OE NAVAL STORES, 



The total yield of 366.5 pounds represents the dip secured from 

 123 cups from June 9, when the first streak was put on, to October 

 31, the date of the last dipping, a period of approximately 20 weeks. 

 The average yield of 0.147 pound per cup per week is about two- 

 thirds as much as secured from western yellow pine in Arizona and a 

 little over half the average yield of southern yellow pine in Florida 

 operations. 



COMPOSITION OF DIP. 



Table 15 gives the results of analyses on Rye samples of pinon dip. 



Table 15. — Results of laboratory analyses on samples of dip from pinon, Colorado. 



Date of collec- 

 tion. 



Rosin. 



Turpen- 

 tine. 



June 30 



July 15 



Per cent. 

 81.3 

 78.3 

 81.0 

 78.3 

 78.0 



Per cent. 



18.7 

 21.7 

 19.0 

 21.7 

 22.0 



Aug.ll.. 



Sept. 1 



Sept. 23 



Average. . 



78.4 



20.6 



Note.— Per cents of rosin and turpentine are calculated for gum free from water and chips. 



The proportion of turpentine in the pinon gum was slightly less 

 than m the gum from Arizona western yellow pme (see Table 7). 

 The turpentine from pinon is composed mainly of pinene and in 

 this respect is similar to turpentine from southeastern pines, but it 

 also contains another oil of quite different physical properties. The 

 turpentine, however, could probably be used for industrial purposes. 



COLORADO EXPERIMENTS ON WESTERN YELLOW PINE. 



(Pinus ponderosa var. scopulorum.) 

 DESCRIPTION OF EXPERIMENTAL AREAS. 



The turpentine experiments on western yellow pine in Colorado 

 were conducted on two areas, one on the Montezuma National Forest 

 and the other on the San Juan. The Montezuma area is about 7 

 miles from Mancos, on a southwestern slope at an elevation of about 

 7,800 feet. The area was lightly cut over several years ago, and some 

 of the largest trees were removed; but it still contains trees of all 

 ages and is a representative stand for the locality. The soil is thin 

 and rocky. One hundred and twenty-five cups were hung on an area 

 of 6 acres. Sixty-eight trees were tapped, ranging from 13 to 32 inches 

 in diameter breast high. The first streak was put on June 10. 



The San Juan area is about 6 miles north of Durango on a fairly 

 steep slope at an elevation of about 7,500 feet. The area contained 

 considerable undergrowth. Plate III, fig. 2, shows a t3^pical view on the 

 San Juan area. One hundred and twenty-five cups were hung on 62 



