Wilmington daily commercial., 1873-12-30
Ths nlannEncture d aanpakaer.

DUPoNTs' WORKS ON THE BRAEDYwNK--TnE m
aREpIENTs AND MANNER IN WHICH dUNPowpER
Is MADE-oArAcfry OF THE MILLS.
The Gunpowder works OF the Messrs. dupont
are situated ON both sides Of the Brandywine,
about three miles above this city. Their capa-
city is 80 600 pounds per day but in one day the
extraordinary amount OF g., ,o0Qlbs was msnufao-
tured.
Sometime during the month of October last
committee from the graduating class OF 1874 in
the Polytechnic College at Philadelphia visited
the works Of the Messrs. dupont, and subse-
quently paper was prepared by H. NJ. Alexan-
der, OF the Committee, and read before the stu
dents. The paper was Afterwards published in
| the Polytechnic Bulletin and from it we extract
what follows.
The manufacture of gunpowder consists
chiefly in mixing the three Ingredients. sulphur,
saltpetre, aud charcoal, in such proportion that,
when he It is applied, the whole becomes ignit-
cd generating great heat, which expands the
gases formed to many times their volume. AT
ter thus stating the ingredients Of which it is
composed, Mr. Alexander proceeds to narrate
tho manner Of the preparation OF the ingred-
ents, one after the other The vast Quantities
OF willow which are seen in transit to the powder
works are reduced to charcoal and thus performs
its office ia the manufacture of gunpowder.
From an explanation OF the preparationof the
several component parts Mr. Alexander proceeds
| to narration of the manner in which they are
combined. He says:
After spending considerable timefn examin.
ing the different operations employed in purify
ing the saltpelre and in listening to an explana-
tion of the various Darts from one who is thor
| ough master of his business, we walked about
| All eighth of mile and entered a very black
/ looking place, whore, as we are informed, the
charcoal and sulphur arc ground together. For
| this purpose the two substances are placed in
barrels, 10 proper proportions. These barrels
have horizontal shaft passing through them
and To and ahgNTN ItAa AnANF atlNFn
| There are about a dozen of these barrels on one
| shaft and. in each barrel is a number of malle-
able iron balls. As the barrels revolye, the balls
| falling about crush the charcoal aud sulphur to
| the proper degree of fneness. When the crush
| ing is complete, the pulverized mixture is passed
| through sieve to remove the coarse pieces OF
| charcoal.
From the mill, tho powdered charcoal and
sulphur are taken to the Incorporating mill
vi o Q they are mixed with the proper propor-
| tion Of the prepared saltpetre. The mixture.
| togt ther with number of zine balls, is there
| placed in barrels made OF buckskin stretched ON
| frames These barrels are driven in a manner
| similar to that in which those used in crushing
the charcoal are driven. SincS there is a small
| amount of moisture in the ingredients, it is nee
essary. while the barrels are revolving that care
| should be taken that the powder does not adhere
| to the siEes. When this is the case, If not at
| tended to. the accumulation Of the powder is
/ likely to hold the balls in it's mass, causing tham
/ to form kind OF fy-wheel, thus increasing the
speed to about sixty revolutions per minute,
| when tue heat produced is liable to ignite the
powder. In order to prevent this accumulation
OF the powder on the sides, OF which acoumula-
/ ton warning is given by tho cessation Of the
| usual noise the sides Of the barrels are struck
| by a wooden mallet. The operation going on
| in the barrels is for the purpose OF producing
| homogeneous mixture Of the three ingredients.
/ When thoroughly Incorporated, the powder
| is taken to y building whore it is mixed with
water, which. in the winter time, amounts to 31
| per cent. and in summer to 4 per cent,
| The powder then goes TO be ground Here it
is so spread oyer the bed of the mill as TO cover
| it to the depth OF two or three inches There
are two large cAst-iron edge wheels weighing
eight tons each. These, which are driven by an
upright shaft, move over the powder, grinding
it to great degree Of ineness. 1t is very nee
| eesary that the powder should not adhere to
these rollers, since, II they should come in con
tact with the naked iron bed heat enough to
| cause an explosion would be the result. There
| are, at one time, but about 100 pounds of pow
der in each Of these grinding mills, so that il
| an explosion should occur III one Of them, iniu-
ry to the neghboring mill may be avoided
| Considerable danger ID connected with the oper-
alton OF this mill, but, to avoid loss of life, no
| employee is allowed to enter 1t without first
stopping the motion OF the rollers.
| After being ground, the powder il removed to
| the pressing mil, where it is oted to pres
sure Of 1000 pounds to the square inch. When
pressed, it is very hard and III the form OF cakes
about two feet square aud one iuch thick. Tsese
are passed. between rollers covered with cogs Of
bell metal. This is merely preparatory to the
grauulatItg operations
Being uuaUle to get into the granulating mill
At that time OF day, we were obliged to DO satis-
fed with examining the machinery which was
| bong prepared for the purpose. The operation
OF graduating is a very simple consist-
ing merely in passing the broken cake through
rollers. These rollers are placed at distance
from each other, varying according to the size
OF the grain to lie prepared, the distance between
them sometimes barely allowing piece OF writ
ing paper 10 pass through As the powder
passes between the rollers. it falls upon a seriss
OF eeve. Tho part which PASSES through the
first sieve falls upon another, which retains the
proper sized gram, allowing the rest to pass
again pissed between the rollers while that
which is too much puverzed ID returned to the
nall to be again pressed
| The next operation is the glazing of the grains
To effect dis the powder is placed in barrels
and, as the barrels revolve upon horizontal axes
tle friction Of the grams against one another
will leave the powder glazed and ready to be
dried,
For this purpose the powder is placed in bags
and taken TO the drying house. In this build
ing IL room about fifty feet long, IN which is a
frame work upon which the slides containing the
powder to be dried are placed. The tempera
lure oil the room is kept IN high as is necessary
for the purpose OF drying the powder. After
| remaining here ten or twelve hours, it il remov
ed Ia another building, where it is packed ant