18 



WESTERN PINES AS A SOURCE OF NAVAL STORES. 



The total weight of scrape obtained from the area at the end of the 

 season amounted to 287 pounds. This is equivalent to a yield of 

 0.018 pound of scrape per face per week, somewhat less than obtained 

 in the Florida experiments (see Table 4). 



COMPOSITION OF DIP AND SCRAPE. 



The results of analyses of two samples of crude gum and one 

 sample of scrape are given in Table 12. The proportion of turpen- 

 tine in the California gum, as shown by these samples, is less 

 than in the Arizona gum (see Table 7). A further analysis of the 

 volatile oil from California western yellow pine shows that it con- 

 tains a considerably smaller proportion of pinene than ordinary 

 turpentine, and contains another oil not found in ordinary turpen- 

 tine. It is, however, probable that turpentine from California 

 western yellow pine will prove of commercial value. Its use is 

 recorded in California at the close of the Civil War, when turpentine 

 operations in the Southeast were practically at a standstill. The 

 operations in California were very crude, however, and were dis- 

 continued as soon as naval stores from the Southeast became available. 



TABLE 12. Results of laboratory analyses on samples of dip and scrape from western 



yellow pine, California. 



EVAPORATION FROM CUPS. 



The loss from the cups by evaporation was tested by weighing four 

 cups approximately half full of fresh gum on September 7 and again 

 on December 1. The average loss in weight was 2.8 per cent. 



COLORADO EXPERIMENTS ON PINON. 



(Pinus edulis.) 

 DESCRIPTION OF AREA AND METHOD OF EXPERIMENT. 



The turpentine experiments on pinon were conducted on the 

 Montezuma National Forest. The cups were placed on a tract 2J 

 miles southeast of Mancos, representative of average conditions 

 in the pinon stands of southwestern Colorado. The elevation is 7,200 

 feet; the surface is rolling with a gentle slope to the southwest; 



