22 
BULLETIN 1064. TJ. 8. DEPARTMENT OE AGRICULTURE. 
With respect to per cent of yield as compared to amount of chip- 
ping surface used up. the narrow method was markedly superior to 
the other two methods. In 1916 it showed an increase in yield per 
inch of height of face of about 10 per cent, and in 1917 of nearly 50 
per cent, over the standard. 
The productivity of the trees on the narrow area at the end of 
the second year of operation, even after a long period of dry weather, 
was very high as compared with that of the trees on the double area. 
Photographs of freshly cut streaks made immediately after ehip- 
Apr MoyJon* Jo/y Avq 3e£>r. Ccr. A>cf. Dec Aon Mov June Ju/y Auq. Svpr. Ccr No* Dec. 
Fig. 5. — Narrow trees. 1916. 
Number of tracheids, observed April to 
December ; in 1916. growth ring. ° Sum- 
mer wood present. 
Number of resin centers per unit area 
i an arbitrary tangential extent : diameter 
o£ microscopic field by the width of the 
annual ring observed). Observed April to 
December, 1916; in 1916, growing ring; in 
1915, completed ring. 
ping are shown in Plate III. figures 1 and 2. The abundant exuda- 
tion of the gum from the narrow-chipped tree shown, even under 
adverse weather conditions, was so striking that the practical tur- 
pentine operator who was managing many crops in that section, and 
had been very skeptical of the narrow method of chipping, expressed 
surprise and satisfaction at the excellent condition of the timber. 
Not all the double-crop trees had " dry-faced M to the extent shown 
in Plate III. figure 1, but many were in that condition, and the 
yielding capacity was in general markedly reduced. 
