The San Francisco call., 1909-03-28
WOOD DECAY DUE
TO TWO CAUSES
Longevity Is Assured Under
Extreme Wet and Dry
Conditions
Government Department Studies
Preservation Treatment
of Timber
Especial Dispdtch TO The Call


WASHINGTON, March 27.-Piles
driven by the hut dwellers of the Bal
tic, centuries ago, are as sound today
as when first placed. The wooden cof-
fins in which the Egyptians buried
their dead are still preserved in per-
feet condition after thousands of years
Of service.
The longevity of timber under these
two extremes of climate and moisture
conditions has naturally made people
ask what causes wood decay? The an
swer is, fungi and bacteria. low forms
of plant life which live in the wood
and draw their nourishment from it,
The organisms are so little that mi
croscope is required to see them, yet
their work results in the destruction
of billions of feet of timber each year
and the railroad corporation, with it's
cross tie bill running up into seven
figures and the farmer who spends q
hundred or so dollars a year for fence
posts are alike drawing upon the
knowledge of experts in all parts of
the world in efforts to learn the most
economical and most satisfactory meth
roads of decay. In studying the means
of preventing decay wood preserving
experts have learned many things
about the obnoxious fungi which sap
the life of timber.
TWO FAVORABLE CONDITIONS
The small organisms can grow either
In light or in total darkness; but all
of them require requisite amounts of
air, food, moisture and heat. If one
or more. of these essential requirements
is lacking they can not live, and the
decay of timber will not take place
Wood constantly submerged in water
never rots. simply because there is an
insufficient supply of air. This condi-
tion accounts for the soundness Of the
old Baltic piles. On the other hand, if
wood can be kept airdry 1t will not
decay because there will then be too
little moisture The timber used by the
Egyptians will last indefinitely, so long
as it is bone dry.
There are a great many cases. how
ever, where 1t is impossible to keep
wood submerged in water, or in an alb
solutely airdry condition. In fact. a
large percentage of the timber which
is used is exposed to the weather, and
is subjected to decay simply because it
contains enough air and enough water
for the decomposiHg organisms to get
a foothold. Decay is most serious
where the atmosphere is warm and
damp, because these conditions are
most favorable for its development. In
the coal mines of Pennsylvania timber
decays in two or three years because
the temperature is warm and constant
and the air is damp. And in the south
the warm, humid atmosphere often
causes the timber to rapidly decom-
pose.
PREVENTATIVE METHODS
Decay may be prevented by two gen.
eral methods-by treating the wood
with antiseptics, thus poisoning the
food supply of the organisms which
cause decay, and by treating 1t with
oils, which render it waterproof A
combination of these two methods is
most commonly used, as when wood is
treated with creosote, which fills up
the pores in the timber and keeps out
water, and is also a powerful antisep-
tic.
The United States government con-
siders the Investigations of the pre-
servative treatment of timber of such
Importance that the business of one
branch of bureau in the department
Of agriculture-the office of wood
preservation" in the forest service at
Washington, is given over entirely to
the work of experiments in co-opera-
tion with railroad companies and in
dividuals in prolonging the life of rail-
road ties, mine props, bridge timbers,
fence posts and transmission poles. Ad-
vice and practical assistance is fur
nished all who request this advice of
the forester. The lengthening of life of
timber means the saving of thousands
of dollars annually through doing away
with the heavy expense of labor and
cost of material for renewals.