YIELD TABLES. AT] 
stand as well as in board feet, and if the amount of timber 12 and 14 
inches and over in diameter were expressed in percentage of the stand 
of trees 10 inches and over. The tables would have a further advantage 
if these values were determined for acres yielding exactly 1,000, 2,000, 
3,000, etc., board feet per acre, instead of for acres yielding these amounts 
in round numbers. Thus for acres which yielded in round numbers 
1,000 board feet the actual stand was 1,416 feet. The predicted yield 
at different decades was, therefore, really determined for acres of 1,416, 
and not of exactly 1,000, board feet. The tables were reconstructed to 
show the predicted yields in percentage of the original stands, and the 
amount of timber 12 and 14 inches and over in diameter, in percentage 
of the stand of trees 10 inches and over, all values being calculated for 
acres yielding exactly 1,000, 2,000, 3,000, etc., board feet.’ 
Present yield per acre of Spruce, amount which can be cut in 10, 20, and 30 years after 
lumbering, and the number of years which must elapse before the same amount can be 
obtained again, cutting down to 10, 12, and 14 inches. 
A.—_SPRUCE PER ACRE 10 INCHES AND OVER IN DIAMETER BREAST HIGH. 
ees to ‘Second cut after Second cut after Second cut after 
ail tree 10 years. 20 years. 30 years. 
inches and | Number y J ie du letval 
over in of acres ae ‘3 aie Bas 
diameter, meas: | Percent- Percent- | Percent- equal cuts 
breast high,| ured. age of Board age of Board Peet: Board | years } 
. a UL, S ° 
py Deane first cut. feet. first cut. feet. first cut. feet. 
1 2 3 4. 5 6 Vv 8 9 
1, 000 139 20 200 60 600 140 1, 400 27 
2, 000 213 15 300 43 860 94 | _ 1,880 32 
3, 000 223 11 330 41 1, 230 70 2,100 36 
4, 000 204 9 360 35 1, 400 56 2, 240 39 
5, 000 106 8 400 33 1, 650 50 | 2, 500 41 
6, 000 71 7 420 32 1, 920 46 2, 760 43 
7, 000 37 i 490 30 2, 100 42 2, 940 45 
8, 000 21 6 480 27 2, 160 37 2. 960 47 
9, 000 4 5 450 24 2, 160 ay | 2, 880 ; 49 
10, 000 4 400 21 2,100 27 2,700 51 
1Tn order to arrive at the future stand after lumbering, for tracts yielding exactly 1,000, 2,000 feet, 
etc., per acre, the following method of interpolation was used: On the horizontal lines of cross-section 
paper there were laid off the different. yields per acre in board feet, and on the vertical lines the future 
yield in periods of 10, 20, and 30 years. Normal curves were drawn through the points of intersection, 
and the values for acres yielding exactly 1,000, 2,000, etc., feet were ascertained by interpolation. 
The same method was used to determine the stand of trees 12 and 14 inches and over for acres yielding 
exactly 1,000, 2,000, 3,000 feet, etc., and also for the intervals required between equal cuts. 
