Daily press. [volume] (Newport News, Va.) 1896-current, 1908-10-22
PROGRESS IN
49,. WOOD PRESERVATION

OF wood preservation than many pee'
pie realize. Lumber users have be-
come convinced that in the chemical
treatment of timber and the cohse-
quent lengthening of the woods lie
that they can save the great cost OF
materials and the labor in renewals.
Just few years ago a prominen,
man, in a paper read before the Pa
cific Coast Railway Club, called atteh'
ton to the pressing need Of thorough
nvestigation OF all processes used III
the preservation of wood. At tha'
time he depl0red the fact that neither
the government nor corporations
would offer inducements to men COM
petent to carry out such investisa'
tons The particular problem which
he had inmind was the treatment OF
billing TO make it resistant to attacks
Of marine WOOD bOrers, such as leredo
and limoria. This problem is indeed
a serious one. but probably no more
50 than that of preserving ties, poles.
and mine timbers. against decay.
About the same time that this
paper was presented before the Pa
cific Coast Railway Club. the United
States Forest Service established an
Office, the duties of which would be
to investigate known preservatiVes
and processes and to devise means.
If possible. whereby the present
methods could be improved or cheap
ened, or new methods developed to
take the place of those already In
use. Since its inception, the office
of wood preservation has made rapid
strides. Up to the present time eN-
periments have been carried on In CO.
operation with corporations. education
al institutio and individuals. to try
out various theories in actual practice,
and the results have proved OF value
not only to the cOOperators. but to
large number Of people having in
terests similar 10 those to which the
particular experiment applied.
Preservative treatment is recogniZ-
ed as a paying proposition wherever
construction timber is exposed to SOIL
or atmospheric influences causing de-
cay. This statement is fully a'tested
by the rapid increase in the use OF
treated timber in recent years. the
increase has been most notable In the
case Of railway cross ties. All OF the
larger companies in the west now use
treated ties to a greater or less ex-
tent, and many Of them operate their
own treating plants.
1t is also notable that the use OF
treated timber is confined principally
to corporations requiring very large
quantities of construction material.
This is largely accounted for by the
fact that the pressure system of I'M
pregnation in common use requires
expensive retorts and machinery. ana
is not adapted to plant Of small ca
pacity. thus making 1t impract,cabie
for a concern using a small or moder-
ate amount of timber to undertake
treating.
Besides the plants operated by cor
porations for the treatment of their
own construction timber. there are
number of plants which do COM
mercial business, but these being To-
Gated at centers CT distribution, wnere
a permanent business is more readily
assured. are not accessible to timber
which goes direct from forest to con-
sumner without passing through such
central distribution point. For econo-
my. the treating should be conducted
at a point where additional transporsa-
ton charges on account Of the treat
ing will be reduced to minimum
The ranchman drawing his timber
from the adjoining forest. should have
on the ranch the means for treating
his fence posts and similar materials.
The mining concern should have at
the mine a plant with capacity adapt
ed to their need. An electro COM
pany whose lines extend over a con-
siderable area and which draws Its
timber from various sources, may fnd
a small portable plant best for treat
ing poles.
For several years the Forest Ser
vice has been experimenting with q
method of impregnating wood. which
requires no expensive equipment. is
simpls in operation. and Is adapted to
a plant Of any desired capacity. II
is now known that all of the more
porous woods can be treated success
fully BY this method. The method
Ia called the open tank" or hot and
cold bath" process. The impresnation
is accomplished by thoroughly heat
ing the timber in tank containing
liquid substance. then running on
the hot liquid and Killing the tank
with cold. or transferring the timber
from q tank containing hot TO q tank
containing cold liquid, or allowing the
whole to COO, without change.
The theory Of the process Is that
the air in the wood cells and inter
cellular spaces EXPANDS when heated
and is partially expelled. Upon cool
ing IT again contracts. thus causing
a partial vacuum. and the pressure OF
the air on the outside forces the lia,
,,;a int tho vo0d Tho nr0~e4a NAV