Edgefield advertiser. [volume] (Edgefield, S.C.) 1836-current, 1898-01-05
TO TELL TREES AGE.
interesting Calculation Has Been Reduced
10 a Science by Experts.

interesting Calculation Has Been Reduced
to a Science by Experts.
IF you want to know how old the
venerable oak on your lawn is you
can easily find out, but you will first
have to cut it down and get cross
section as near the base as possible.
Perhaps your curiosity would not JUS
tlfy such a sacrilegious use 4 ,le
woodman's axe, yet it may be none the
less interesting to learn that accord
ing to Mr.. B. E. Fernow, chief Of the
Forestry Division of the Agricultural
Department at Washington, the cal
culation Of timber tree ages IN the
temperate part Of the United States
has been reduced to science, and Its
accuracy has been tested by thousands
of experiments.
In the trees referred to the wood Of
the stem is laid on in sheets or lay
ers, which on a cross section appear
as so many concentric rings, one being
formed each growing season. The
rings appear as alternate narrow
bands Of lighter or darker color, the
dark line, or summer wood" occupy
ing the outer portion Of one ring and
being sharply contrasted against the
highest portion of the inner, higher OF
Spring wood" part of the next ring.
These annual rings differ in width,
commonly averaging from one-eighth
of an inch to three-eighths in hard
woods and from one-twentieth to one
enghth in conifers, and cases are not
rare where a whole century's growth
Of a spruce or balsam amounts to but
to or three inches on the radius OF
the stem. In all young, sound and
thrifty trees, Mr.. Fernow says, the
rings are laid on with the utmost reg
ularity and cross section Of stem
furnishes not only information as to
the age of the grown section, but Is
fair indication of the life history OF
the trae, periods Of suppression and
thrift peing indicated respectively by
zones of correspondingly narrow or
broad rings. In such timber the
countings along different radii always
give the same result.
In very old, slow grown trees a dif-
ference may appear Of from one to five
rings, which < not due to the inability
Of the eye to detect an extremely mar
row ring, is based on the actual alb
sence Of the ring, or rings, along a
given radius, unfavorable circum-
stances having led to a failure of their
regular, continuous development. A
similar irregularity has been observed
in densely shaded Or otherwise stunted
timber, and also in timber injured by
coal smoke; so that a given ring, or
years growth, was found developed
twenty feet from the ground. but en-
tirely absent near the stump OF the
same stem.
To determine the age of tree it is
desirable to make clean, smooth cut.
Frequently magnifying glass will be
found indispensable. Count along the
greatest radius, avoiding covered
wounds and other obstacles. Since a
Seeding of white pine, for instance, Is
only one foot high when five years
old, says Mr.. Fernow, and since the
parts of this five-year-old Seeding are
never raised upward by growth, all
growth being by the addition Of new
parts, cross section two and haif
feet from the ground does not include
this fve-year-old tree at all. So, If the
number of rings on the stump section
is 100, the real age Of the tree is not
100 years, but 100 plus about six. For
most purposes it is sufficiently near
the truth to make this allowance. but
when greater accuracy is desired, the
cut must be made level with the
ground, so as to include the Seeding
:, stem as we'll