Semi-weekly herald., 1907-10-21
Preserve Wooden
Posts and Poles

place in the material development of
the Rocky mountain region th!tI the
telephone and the telegraph. I'M
provemen.s In overland Transportation
furnished by steam roads and in rapid
communication made possible by the
use OF the wire for delivery of mes
sages have gone hand in hand in
making 'he great west thoroughly ac-
cessible and in Fastening develop.
ment
person seldom realizes the import
ant part which the telephone and tele-
graph play in his daily life. and few
know the enormous amount of capital
Invested and material that is required
to construct and maintain the extern
sive lines. Thirty million poles are
used in the United States on 800, 900
miles of telephone and telegraph lines
This does not include the large num-
ber of poles which are required by the
electric lighting and transportation
companies. Most of the poles in use
are cedar but throughout this Rocky
Mountain region this is not available.
and Douglas fir is substituted. Doug
las fir, while not so durable as cedar
Is so much more lasting than the other
available timbers. that its use has
been widely extended
AS the telephone and telegraph lines
Increased to meet the demands of bust
ness brought about. by the growth of
railroads and towns, 1t became neces-
sGry to cut large areas of timber
lands to supply the poles holding the
wires. For a long time timber was
50 plentiful. that suitable poles could
be easily obtained without going far
rom the lines under construction
Now, however, the considerable dis
lance that the poles must be trans
ported in many cases and the general
scarcity of timber has tended to raise
the cost. Consequently. pole users
rave been compelled to find some
;heaper, more abundant timber to re
place the expensive Douglas fir or dis
;over some inexpensive way of max
ing it last longer by fighting off de
ray.
The decay of wood is caused by the
| action of low forms of plant life called
nngi and bacteria. These live upon
| the wood and in time completely de
| stroy it. In order to grow they re
1uire a sufficient amount of heat. air
moisture, and food. All of these re
| 1uirements are met in most parts oi
he United States. When the pole is
set, however, air and moisture gener
| llly exist in requisite amounts only In
| that portion of the pole near the sur
| ace of the ground The portion o.
] the pole buried several feet under
| ground does not furnish them witt
| The necessary air. while that par
| above the ground. In most cases, con
tans insufficient moisture for theiI
development. If the part near the
| ground line can be protected from
attack. the life of the pole can bt
materially increased.
Many methods have been tried a
various times to protect this vita
part of the pole Most of these con
sisted in applying oils or paint ol
similar substances with brush tt
| the butt. With a few exceptions, they
have been largely abandoned as no
giving the desired protection. The
| substance applied remained almost ea
| tirely upon the surface of the woot
| and as a result. seasoning checks ant
| wind shakes ruptured the coating and
exposed the untreated wood to attack
by fungi, which soon destroyed the
| pole.
The forest service of the United
States department of agriculture has
spent considerable time in developine
a method by which the butts of poles
can be successfully and economically
preserved against decay, with a conse
quent Increase in the life of the whole
! pole. This consists in immarsing them
| in alternate baths of hot and cold
| preservative, such as creosote or zinc
chloride. The poles are placed in a
tank of hot preservative to a depth OF
! one foot above the ground line when
| set, and kept there for few hours
depending upon the species and condi
tion of the timber. The pole is then
placed in bath OF cold preservative
for short period, which completes
the treatment.
When the wood is heated in the first
bath. the air and moisture in the wood
cells and intercellular spaces is ex
| panded, and some of 1t is driven out
| Upon immersion In the cold preserva.
tive. the difference in temperature
causes the expanded air and moisture
to contract. thus forming partial vac
uum. which causes the oil to peno-
trate the wood TO the desired depth
The wood to be treated should be air
seasoned.
Douglas fir is a dense timber. and
the heartwood is very difficult t. pene.