24 
BULLETIN 604, U. S. DEPARTMENT OF AGRICULTURE. 
continues for about 200 years, after which it drops off, slowly at 
first, but more and more rapidly as old age approaches. The period 
of maximum diameter growth follows closely the period of max- 
imum height growth, beginning about the time height growth cul- 
minates. The maximum rate is attained shortly after the periodic 
annual height growth falls below the mean. 
Table 14: gives, for the sake of comparison, the average diameters 
breasthigh at different ages for trees growing in different localities. 
Considerable difference will be noted in the growth rate prevailing 
in the localities represented, but it also will be found that the 
period of rapid growth corresponds closely in every case. 
Table 14. — Diameter growth of incense cedar outside dark at breastheight. 
[CUKVED.] 
Locality. 
Age. 
Eldo- 
rado 
Na- 
tional 
Forest. 
Plumas 
Na- 
tional 
Forest 
(T. 24 
N.. R. 
5E.). 
Shasta 
Na- 
tional 
Forest. 
Modoc 
Na- 
tional 
Forest. 
Kern 
Na- 
tional 
Forest, 
Tahoe 
Na- 
tional 
Forest. 
Plumas 
Na- 
tional 
Forest 
(T. 24 
N., R. 
10 E.). 
Kla- 
math 
Na- 
tional 
Forest. 
Aver- 
age. 
Diameter breasthigh outside bark. 
Years. 
30 
Inches. 
1.6 
3.8 
8.7 
13.9 
19.2 
23.6 
27.0 
29.7 
31.8 
33.5 
35.2 
37.0 
38.7 
40.4 
Inches. 
0.1 
2.1 
5.4 
8.7 
12.6 
17.4 
23.2 
25.4 
27.8 
30.2 
32.5 
34.6 
36.6 
38.5 
40.1 
41.7 
43.1 
44.4 
45.3 
••46.0 
Inches. 
1.4 
3.4 
7.2 
11.4 
16.0 
20.0 
23.4 
26.2 
28.4 
30.6 
32.6 
34.6 
36.6 
38.4 
40.0 
41.4 
42,5 
Inches. 
0.4 
1.8 
5.2 
9.0 
12.8 
16.6 
20.1 
23.0 
25.5 
28.0 
30.3 
32.6 
34.8 
37.0 
Inches. 
1.6 
3.8 
6.3 
12.9 
17.2 
20.9 
24.0 
26.7 
28.9 
30.8 
32.4 
33.8 
35.0 
35.9 
36.9 
37.7 
38.6 
39.4 
Inches. 
1.1 
2.5 
5.3 
8.1 
11.1 
14.1 
17.0 
19.7 
22.0 
24.0 
25.8 
27.5 
29.1 
30.5 
31.9 
33.1 
34.3 
35.3 
Inches. 
1.2 
3.8 
5.7 
8.9 
12.2 
15.5 
18.4 
20.8 
22.5 
24.0 
25.3 
26.6 
27.9 
29.9 
30.2 
31.1 
31.9 
32.5 
33.1 
33.7 
Inches. 
1.0 
2.3 
5.0 
8.0 
10.7 
13.5 
16.2 
18.9 
20.3 
23.0 
24.4 
25.7 
27.0 
28.3 
29.6 
31.0 
32.3 
33.5 
Inches. 
1.3 
40 
3.2 
60 
6.4 
80 
9.8 
100 
13.6 
120 
17.8 
140 
160 
180 
200 
21.3 
23.6 
25.7 
27.8 
220 
240 
260 
280 
29.8 
31.7 
33.6 
35.4 
300 
36.9 
320 
38.2 
340 
39.2 
360 ! 
40.1 
380 
40.9 
400 
41.6 
Basis number of stump 
27 
100 
37 
26 
23 
20 
101 
26 
360 
VOLUME GROWTH. 
The cubic contents of the entire stem and the board-foot contents 
of the merchantable portion of trees of different ages grown in 
virgin stands are given in Table 15, together with the average 
heights and diameters on which these volumes are based. 1 
1 Complete volume tables will be found in the Appendix. 
