14 
In the following table are given the results for ash. The trees 
are grouped by one-inch diameter classes. The figures given 
are the actual averages obtained in the field. 
TABLE VI. ASH 
D.B.H. Height Bole Crown Radius _ Equivalent 
Inches in Feet in Feet in Feet Trees per Acre 
7.0 72 47 6.5 459 
8.1 74 46 6.0 385 
9.0 79 47 6.6 318 
10.1 79 45 7.1 275 
10.9 82 48 7.7 234 
12.0 80 44 8.7 183 
13.1 80 44 10.0 139 
Basis 109 trees. Age 60 — 70 years. 
It will be seen that though the spacing of the trees as given 
by the crowns amounts to a difference of nearly one hundred 
per cent yet the total height averages about the same for all 
classes, except the first two. This implies that up to a certain 
point, at all events, closeness or openness of the stand does 
not affect height growth. 
The average length of clear bole in all is comparable. This 
length averages around forty-five feet but in a managed 
forest it could be taken at fifty feet, or even at fifty-five feet. 
Ash trees felled on Harvard Forest, from 8” to 12” in diameter 
have given a clear length of sixty feet. That the average 
length of clear bole is practically the same for all the crown 
radii given is important since it indicates that the limit of 
thinning an adequately stocked young forest of ash has not 
yet been reached; or, in other words, a system of thinning 
which would produce these results is not severe enough to re- 
tard natural pruning. Each row of figures in the preceding 
table represents a possible end point at seventy years for any 
system of progressive thinning. Which is the best, however, 
must be settled by the objective of the forester. In general, 
this objective is the greatest money return. The financial 
yield is itself governed by the total yield and value of that 
yield. 
