The record-union., 1899-09-11
WOOD MADE FIRE-PRoOF.
Non-Inhammable Wood for Ameri-
can War Ships.

All the wood which has been used in
the construction of United States bat
tleships, cruisers and torpedo-b boats for
the last four years has come from a
single little yard on the East River,
filed with great piles of boards that
look as if they had been washed ashore
from some wreck after floating for
months, until they were soaked with
brine. Their weathered appearance is
due to the fact that they have been
subjected to a fire -proofing process by
which all pitch and resin are driven out
of the pores of the wood and certain
sulphates and phosphates of ammonia
forced in. AS seen in the yard they are
stacked UP for several months air.
drying. After that no heat or flame
can destroy them.
The manager of the fire-proofng
works, by way of illustrating the eff
cacy Of his methods, will take piece
Of the wood and toss it into one of the
big furnaces, on a bed Of white-hot
Goals that would easily melt iron. TAX
ing it out ten minutes afterward, one
hnds it to be charrel to a depth Of one
sixteenth of an inch or so, but it does
not carry the ghost of a flame or spark,
nor thread of smoke. Split open, it
shows clean white wood from surface
to core, not fiber injured by the heat
to which it has been subjected.
The main part of the works in which
this is accomplished consists of two
huge cylinders seven feet in diameter
and one hundred and six feet long.
Little railroad tracks, thirty inches
XVi6a o1n hot af
connecting with the tracks that reach
all parts of the yard. Low, fiat cars,
with hoops like those of a prairie
schooner run on the tracks, and on
these the bright new lumber is piled in
cylindrical loads, under the hoops.
When string of cars is ready to run
into the cylinder a wire cable is run
over complicated system of pulleys
and hooked to the last car, the donkey
engine reels in the cable, and the cars
slide into the long tunnel The door is
closed and made firm against pressure
by radiating lever bolts. Then the
cylinder is filled with steam at COM
paratively low pressure, until the wood
| is thoroughly softened. The steam is
then drawn out and the air exhausted
in the cylinder, drawing the moisture
out of the wood, and with it anything
else which is in the pores, leaving them
empty and ready for the next process.
A compressor sends into the cylinder a
solution of phosphates and sulphates
OF ammonia under high pressure, which
forces it into the fibers of the wood and
thoroughly impregnateS every plank
with the solution
Though conducted on a wholesale
scale, the process is a delicate one, and
is watched at every stage by the man
ager, who is also the inventor and per-
fecter of the process, with as Jealous
care as housewife watches her pre-
serving kettles. This care is neces-
sary to make good the boast of the
company, that their process is the only
one which does not impair the strength
! of the wood. or render it unfit for
shellacking or polishing. A few de-
grees too much heat, or a few pounds
too much pressure, would destroy the
fibre of the wood. Too low a heat or
pressure and the process would not be
thorough The amount of pressure
necessary varies from 80 to 120 pounds
/ to the square inch, according to the
kind of wood which is being treated. A
close grained wood like mahogany, not
only can stand more pressure o than
pine, but requires 1t in order to force
the solution to the core of the thick
planks. The manager must know just
what pressure each wood requires, and
what is more, he must see that it gets
it. My engineer is a good mechanic, "
he says, "but I don't trust him in this
case. Where a mistake means the
running of thousands of feet of valua-
BILE lumber, prefer to keep an eye on
things myself.
| So he watches the pressure-g gauges
when he is at the works, and inquiries
hourly by telephone when he is away
| When the little cars of steaming planks
are drawn out of the cylinders, he
stands by, slicing off chip here and
there with his knife, examining it with
a knowing eye, testing it and pulling
it into shreds. Then he goes to a pair