YIELD OF TURPENTINE AND ROSIN. 7 



figures are 2.8 and 2.9 per thousand, respectively. These trees may 

 have died from tapping or from natural causes. If the dead faces 

 were the result of turpentining, it would indicate that standard 

 chipping was hardest on the timber, the double next, and the narrow 

 easiest. It is logical to assume, however, that double chipping 

 would be severer than the standard. Since most of the trees died 

 early in the season, it is probable that method of chipping had little 

 effect. 



Table 5. — Comparative yields per crop with respect to' height of face. 





Height 

 of face. 



Num- 

 ber of 

 streaks. 



Aver- 

 age 



height 

 of 



streak. 



Turpentine. 



Rosin. 



Plot. 



Total 

 yield. 



Per 



inch 



of 



height. 



Increase. 



Total 

 yield. 



Per 



inch 



of 



height. 



Increase. 





Inches. 

 21.95 

 12.85 

 23.67 



38 

 38 

 70 



Inches. 



0.58 



.34 



.34 



Gallons. 

 3,260 

 2,693 

 4,267 



Gallons. 

 148 

 209 

 180 



Per cent. 



Pounds. 

 105,539 

 87, 014 

 143,542 



Pounds. 

 4,808 

 6,771 

 6,064 



Per cent. 





41.2 

 21.6 



40.8 



Double 1 : 



26.1 







1 The narrow and double areas had four standard streaks before the experiment started. The height 

 of the four streaks averaged 2.75 inches from 25 measurements. With this allowance, the streaks on the 

 narrow and double areas averaged 0.30 and 0.32 inch, respectively. The corrected height for the double 

 face is 22.20 inches and for the narrow face 11.38 inches. 



PRACTICABILITY OF DOUBLE CHIPPING. 



In the experiments the double chipping was done on exact schedule. 

 Certain trees were chipped always on prescribed days of the week, 

 except in a few instances when weather interfered. It is very 

 improbable that an exact schedule could be maintained on a 50-crop 

 place, but for practical purposes this would not be necessary. In 

 the experiment the number of faces for double chipping was made 

 small enough for the chipper to cover the ground easily on scheduled 

 time. In practice each chipper would have about 4,000 faces. 

 Since few chippers can handle more than this number in three days, 

 it is improbable that the second streak would be applied too soon. 

 It is expected that a streak would be missed occasionally, as this 

 frequently happens with the present method of chipping. The idea 

 is not to have a rigid schedule impossible to follow, but so far as 

 possible to make two streaks per week where the old method requires 

 one, these two streaks not to increase the height of the face more 

 than the one standard streak. In every case, however, at least 

 three days should elapse between streaks. 



The chief problem would be to find a sufficient number of chippers. 

 The smaller streak is not difficult to cut. More care is required in 

 making it, but less effort is required to drive the hack through the 

 wood. Standard No. or No. 00 hacks were found to give the best 

 results. 



