16 
top and partially or completely suppress the other pines. The height 
growth of Norway pine is best in full sunlight, when slightly crowded. 
The average height growth of saplings in fairly well-stocked stands 
is shown in Table 3. No measurements were made of the growth in 
height of older trees. From the measurements of height on diameter, 
Table 4, and the measurements of diameter on age, Table 7, it was 
possible to construct a table of height growth based on age. This 
table is based on the assumption that diameter and height growth 
are roughly proportional. Thus, if the height of a tree of a given 
diameter is known and also the age of the diameter corresponding to 
the height of this tree, the age of the tree having this height is 
thereby determined. Table 5 has been constructed after this plan. 
It shows the average height of trees of different ages. Figures for 
minimum and maximum heights are also given. The maximum 
trees grew in Wisconsin in mixture with white pine and were domi- 
nant. The minimum figures are for slow-growing suppressed trees. 
Table 3. — Height growth of saplings in northern Minnesota. 
Age 
(years). 
Height. 
Age 
(years). 
Height. 
Age 
(years). 
Height. 
Age 
(years). 
Height. 
Feet. 
Feet. 
Feet. 
Feet. 
1 
0.3 
8 
4.9 
15 
15.0 
22 
23.0 
2 
.6 
9 
6.0 
16 
16.7 
23 
23.8 
3 
1.0 
10 
7.2 
17 
18.1 
24 
24.6 
4 
1.5 
11 
8.5 
18 
19.3 
25 
25.5 

2.2 
12 
9.9 
19 
20.4 
26 
26.3 
6 
2.9 
13 
11.4 
20 
21.3 
27 
27.1 
' 
3.9 
14 
13.1 
21 
22.1 
28 
28.0 
Table 4. — Minimum, average, and maximum heights based on diameter, Minnesota and 
Wisconsin. 
Diameter 
Height. 
Diameter 
Height. 
breast- 
high 
breast- 
high 
(inches). 
Minimum. 
Average. 
Maximum. 
(inches). 
Minimum. 
Average. 
Maximum. 
Feet. 
Feet. 
Feet. 
Feet. 
Feet. 
Feet. 
1 
11 
12 
16 
18 
61 
88 
112 
2 
16 
20 
28 
19 
63 
90 
113 
3 
18 
27 
41 
20 
66 
91 
114 
4 
21 
34 
52 
21 
68 
92 
115 
5 
24 
41 
63 
22 
71 
94 
116 
6 
26 
47 
72 
23 
73 
95 
116 
7 
29 
53 
80 
24 
76 
96 
117 
8 
32 
58 
87 
25 
78 
97 
118 
9 
35 
63 
93 
26 
80 
99 
119 
10 
38 
67 
97 
27 
83 
100 
120 
11 
41 
71 
101 
28 
85 
101 
121 
12 
44 
74 
103 
29 
87 
103 
122 
13 
47 
77 
105 
30 
89 
104 
123 
14 
50 
80 
107 
31 
91 
105 
121 
15 
53 
82 
108 
32 
93 
106 
125 
16 
55 
85 
109 
33 
95 
108 
126 
17 
57 
87 
110 
34 
98 
109 
127 
