The Cook County herald., 1905-12-09
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CfI;IiAlQZ

,NISCEI;l;A
Fungus Attacks on Telegraph Poles.
The length Of service of telegraph
or telephone pole Is determined in
section of the pole not more than
foot or foot and half long. In a
standing pole this section extends
about six or eight inches above and
below the top of the ground. This
is the universal point of attack upon
the life of the pole, and is called its
breaking point. Decay is the arch
enemy Of these poles. It sets In at the
ground line and reaches both up and
down the pole, but only so far as the
conditions exist which promote the
growth of wood-destroying fungi. A
Jew inches below the ground there is
lack OF the necessary oxygen and heat,
while at about the same distance
above ground the requisite moisture
falls. The exact time at which decay
begins its work depends upon the cli-
mate, the character of the soil and
similar conditions. In a hot, moist
climate it ordinarily sets in with
great rapidity. But at best, in very
few years after the pole is set the
struggle has commenced. The decay
soon girdles the pole and gradually
eats into 1t deeper and deeper until 1t
Is SO weakened that it breaks under
the weight of its equipment.
The strain upon the pole from wind
pressure and the weight of it's cross.
arms and wires is calculated for the
ground line. When the diameter OF
this ground line is constantly de.
creased, the strength of the pole is
proportionately reduced, and it be-
| comes only question of time when
the pole must fall. Chestnut and white
cedar have been found, among avail
able woods. most successfully to resist
decay: but the life of the former is
only from twelve to fifteen years, and
OF the latter ten to twelve years. The
cooperative study of the bureau is for
the purpose Of extending, if possible,
this time.
The experiments already made by
the United States Forestry Bureau
show conclusively that poles can be
subjected to a prescrvative treatment
which insures materially heightened
service. This treatment consists in i'm.
pregnating the wood with antiseptics
which prevent the growth of the fungi
that cause decay. The treatment of
telegraph and telephone poles, when
attempted at all in this country, gen.
orally has been applied to the whole
pole. requiring the use of air-tight cyl
inders 100 feet long or more. In these
the poles are subjected to live steam
-. some time, when vacuum is Gre
ated. Creosote is then run in and
pressure applied to force it into the
wood. Manifestly this is laborious
process. Yet for telegraph and tele.
phone poles only about one foot of the
entire length needs to be made i'm
mune from fungus. II this foot at the
fatal ground line can be preserved
from decay, the rest of the pole will
take care Of itself. Experiments will
now be made in treating the butts
OF the poles for distance of about
eight feet, thus carrying the antisep-
tics just beyond the zone of decay
attack. The creosote method will be
used and dead oil Of coal tar forced
through the butt of the pole.
The telegraph companies have made
little use of preservative treatment.
They employ millions Of poles on their
various lines, and it would be tire.
mendous economy to add even a few
years Of service to the life of ,~''
pole. But there will be another L.. &C
saving both to them and to the forest
through preservative treatment. To
provide a good margin against decay,
poles are now much larger than de-
manded by the strain upon them. 1t
is expected that decay will quickly eat
away furrow around the pole at the
ground line, and the diameter Of the
pole at that point is gauged to allow
for this weakening process. When it
is known that decay. in certain num-
Der Of years, cuts the diameter from
perhaps IL to inches, and that below
inches the weakened pole falls. the
course to be pursued is obvious. Anti
septics prevent, for the time of their
| effectiveness, the starting of decay.
| and thus permit at the outset the Sc
lection Of an S-inch diameter rather
than a 12-inch. The inches saved
| represent a tremendous difference in
the size and age Of trees used for
poles. Both the companies and the