The Grenada gazette. (Grenada, Miss.) 1885-18??, 1886-04-10
GuNPoWpER,
How h Ingredients Necessary to Its
ManUacture Are Prepared.

How tho Ingredients Necessary to Its
Manu~cturs Are Prepared.
Gunpowder is composed of three
materials - sulphur, saltpeter and
charcoal. But tossing these materials
together any way does not make gun
powder by any means. There is a
method, and it is somewhat COM
dictated. That pursued at the most
famous factories is as follows: The
ialtpeter chiefly from Bengal
Ind other provinces in India, where it
is found mixed with the soil and as
an incrustation on the ground. 1t is
boiled and c~rystalized by evaporation.
Before it is used at the factory it is
purified by a process which acts on the
principle that hot water will receive in
the solution more of the saetpeter than
the impurities mixed with it. So the
saltpeter is boiled in water, the result
ing solution filtered and cooled in large
vats, at the bottom of which the pure
saltpeter is deposited in fine crystals.
1t is then washed, dried and stored in
bins, care beng taken that no sand or
gritty particles are introduced as I'M
der pressure they might produce an
explosion.
The same precautions are taken with
regard to the production of the sulphur
and charcoal. The best sulphur comes
from Sicily. 1t is purified by q distil-
ling process, which brings it out in
handsome yellow crystals. Then it is
pulverized by being ground under iron
runners and sifted in a kind of revolv-
ing cylindrical sieve called a "slope
reel" Alder and willow are planted
near the factories, and the charcoal
from these is used for common powder,
and black dogwood is used for fine rifle
powder. The charcoal is not prepared
in pits, but the wood is sawed into
short lengths and packed into iron cyl
inders, called slips, which are placed
on a small carriage and run into a re-
tort like that used in gas works. Here
the cylinders are exposed to the tlafnos
for a period Of two and a half or three
and a half hours. the gas issuing from
the wood being utilized for fuel. The
charcoal, when taken out, is ground in
a machine like a giant coffee-mill, and
then sifted like the sulphur.
The next process is mixing the in
gradients. The proportions vary in
different countries. For English Gov
eminent powder of every kind it is
~saltpeter, seventy-tive parts; sulphur,
ten; charcoal, tfteen-the sulphur be-
ing reduced almost to a minimum, as
its chief use is to ignite the charge and
hasten its motion, The ingredients
being weighed for q charge of fifty
pounds, are poured into a ''churn,'
which is a revolving drum placed hori-
zontally. and having within it an axis
revolving in a different direction from
the drum, and furnished with eight
rows of projecting arms. So rapid is
the action of this machine that three
minutes is sufficient to mix the ingre-
dents. 1t is then called the green
charge" and is ready for the incorPo-
rating mills, where the object is to
make the mixture so intimate that q
new substance is created. namely, gun.
powder.
The Incorporating house Of Waltham
have thirty-two separate mills. Each
mill consists of a pair of runners
coupled together by a strong axle.
This axle rests in the socket OF an up
right shaft, which, passing down
through the mill-bed, is connected by
bevel wheels with Il revolving horizon
tai shaft driven by steam or water,
power. The runners are of Dcrbyshire
limestone and iron, and weigh from
three aud one-half to four tons. The
size of the iron ones is from three and
a half to seven feet in diameter. The
mill-bcd-a circular vat with flat bot
tom and sloping sides-is of stone or
metal. On this bed fifty pounds of the
green charge is spread and moistened
with water, and the mill is set going.
Common powder is left under the mil
three hours. rifle powder five hours.
On leaving the mill the gunpowder
is in the form of a soft cake which
easily breaks up into dust. This is
pressed in layers between plates OF
copper or gunmetal to increase its
hardness or density, and then made in
to the required form by machinery,
Minneapolis Commercial Bulletin.