5 
For most purposes it is sufficiently near the truth to make this 
allowance, but where greater accuracy is desired the cut must be 
made level with the ground, so as to include the seedling stem as 
well. Here, however, the lesser distinctness of the rings in the seed- 
ling and its slow 
upward growth 
will always 
leave an uncer- 
tainty, which 
for old or large 
trees readily 
amounts to two 
to five rings, 
varying with 
species and na- 
ture of origin, 
that is, whether 
from seed, or 
sprout, etc. 
From what 
has been said, it 
is clear that for 
an ordinary tree 
100 years old, 
the record for 
the total age is 
exact within 
about three to 
five years; for 
a very old tree, 
200 years and 
over, it is accu- 
rate within 
about six to ten, 
or within 3 to 5 
per cent, if the 
growth is fairly 
normal, but may 
be amiss by as 
Si 
Fic. 6.—Blaze in tree trunk: a, front view; b, cross section on line A. B. 
ina. 
many as twenty years and more, if stunted at any time. Where, 
as 1S common, it is not so much the total age, but a certain portion 
of this age which is desired, as for instance, if we wish to know how 
old the tree was when 12 inches in diameter or when 60 feet high, 
the per cent of accuracy is correspondingly increased. The same is 
