14 



WESTERN PINES AS A SOURCE OF NAVAL STORES. 



low and high faces was kept separate and typical samples chosen 

 for analysis. 



COMPARISON OP YIELDS PROM NORTH AND SOUTH FACES. 



The total yield for the -50 cups on the north side of the trees from 

 the first dipping on June 3 to the last dipping on November 3 was 

 242.6 pounds and for the south cups 266.2 pounds. These weights 

 show a 9 per cent greater flow on the south side of the trees than on 

 the north. Figure 2 shows the average yield per week for both the 

 north and south faces of each of the 50 trees arranged in order of the 

 yields from the south faces. Twenty-seven south cups yielded 

 more than the corresponding north cups, while 17 north cups showed 

 an excess over the corresponding south cups. The remaining six 

 trees had about the same flow for both cups. The diagram shows 



FIG. 2. Comparison of flow from north and south faces of each of fifty trees. 



the tendency of faces on the same tree to give the same yields. 

 Trees having an exceptionally good or exceptionally poor flow 

 generally show it in both faces. 



COMPARISON OP DIP FROM HIGH AND LOW PACES. 



While there was an attempt to determine what greater loss there 

 would be, if any, from evaporation from the higher faces, it was 

 found to be impossible to select trees with comparable flows. As 

 far as it was possible to carry out the experiment, the indications 

 were that the proportions of rosin and turpentine in the dip were 

 not affected by the height of the face, and this would seem to show 

 that there was no appreciable difference of evaporation on faces 

 with a difference in height of 15 inches. Table 8 gives the composi- 

 tion of dip from the two heights of faces. The results of the analyses 

 given in this table are very similar to those given in Table 7. 



