CALIFORNIA EXPERIMENTS ON WESTERN" YELLOW PINE. 



17 



WEATHER CONDITIONS. 



Table 10 shows the weather conditions during the California 

 experiments, including three months preceding and one month 

 following. The mean temperature on the area from June 1 to 

 November 30 was a few degrees lower than the mean temperature 

 recorded for the Florida 1 experiments from March 17 to November 2. 

 The diurnal range is much greater than in Florida. The total rainfall 

 on the California area for the period of the experiments amounted 

 to only 2.16 inches. 



TABLE 10. Meteorological record, Northfork (California') ranger station, 1911. 



YIELDS. 



Table 11 shows the weights of gum secured from the area at the 

 various dippings. The average yield of 0.281 pound per cup per 

 week is slightly greater than that in the Florida experiments (0.263 

 pound; see p. 9), but it should be kept in mind that the California 

 experiments were not begun until July and that had they been started 

 earlier in the season this average might have been lower. Seventeen 

 faces were chipped at monthly intervals during December, January, 

 and February. A yield of 16 pounds of dip was obtained, which 

 shows that gum continues to flow throughout the winter. 



TABLE ] 1. Weight of dip obtained from western yellow pine in California (968 cups). 



i Forest Service Bulletin 40, A New Method of Turpentine Orcharding, by Charles H. Herty. 



