The Louisiana populist., 1898-01-07
TO TELL TREES AGE.
interesting Calculation Has Been Heouceo
TO Science by Experts.

to science Dy CHpeitS
IF Won want to know how old the
venerable oak on your lawn Is you
can easily find out, but you will 1'rse
have to cut it down and get cross
section as near the base as posslble.
Perhaps your curiosity would not JUS
tify such sacrilegious use OF the
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, ana lts
Accuracy has been tested by thousands
of experiments
In the tres 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 Deihg
formed each growing season. Inc
rings appear as alternate narro"
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-eishtk
of an inch 70 three-eighths in hard
woods and from one-twentieth to one
enghth in conifers, and cases are not
rare where q. whole century's growth
of a spruce or balsam amounts to bU'
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 a cross section of a stem
| furnishes not only information as tc
the age of the grown section, but i:
fair indication of the life history O
the tree, periods of suppression ant
thrift being indicated respectively b!
zones of correspondingly narrow o.
broad rings. In such timber tn
countings along different radii alway
give the same result.
In very old, slow grown trees diff
ference may appear of from one to nv
rings, which if not due to the inabllit
Of the eye to detect an extremely mai
row ring, is based on the actual aD
sence Of the ring, or rings, along
given radius, unfavorable circum
stances having led to failure OF thel
regular, continuous development. !
similar irregularity has been observe
In densely shaded or otherwise stunte
timber, and also in timber injured b
coal smoke; so that given ring, Q
years growth, was found develope
twenty feet from the ground, but er
tirely absent near the stump OF tn
same stem.
To determine the age of tree 1t
desirable to make a clean, smooth Gu
Frequently magnifying glass will
found indispensable. Count along tn
greatest radius, avoiding covere
wounds and other obstacles. Since
seeding of white pine, for instance,
only one foot high when five veal
. old, says Mr.. Fernow, and since tt
parts of this five-year-old Seeding al
never raised upward by growth, a
growth being by the addition OF ne
parts, cross section two and a ma
feet from the ground does not inclu'
this five-year-old tree at all. So, il Il
number of rings on the stump sectit
!. is 100, the real age of the tree is n
4 100 years, but 100 plus about six. r
most purposes it is sufficiently ne
l. the truth to make this allowance, b
when greater accuracy is desired, t
cut must be made level with t
o ground, so as to include the seedlil
stem as we'll.