no g v N p c 
"by the trituration of the three materials, in mills furnifti- 
ed with an apparatus adapted tothis'purpofe ; and theme- 
chanifm of which.is fo well known as to render a parti¬ 
cular defcription of it unneceffary. We (hall at prefent, 
therefore, confine ourfelves to give a fuccinft idea of the 
principal operations executed in our improved powder- 
tnanufaftures. 
“ In the compofition of the powder employed by mi¬ 
ners, there are 13 pounds of faltpetre, 4 of fulphur, and 
3 of charcoal. In the fine powder ufed in war, 15 
pounds of faltpetre, 2 pounds 8 ounces of charcoal. A 
fingle peftle is appropriated to each 20 pounds of the 
mixture. The materials are firft ftirred with a ftick, 
and a fmall portion of water added to them, in order to 
prevent the volatilization of the fulphur and charcoal. 
The pounding ufually continues twenty-one hours; the 
mean velocity of the peftles is about fifty-five ftrokes in 
a minute ; their weight is eighty pounds ; -and they rife 
and fall to the height of afoot. The pafte is removed from 
one mortar to another every hour, during the three firft 
hours ; and afterwards every three hours. At each 
change, care is taken to preferve the neceflary humidi¬ 
ty, in.order that the pafte may retain its coherence. 
When the pafte is fufficiently formed, the mixture per¬ 
fect, and the divifion complete, it is taken out of the 
mortars, and depofited in the graining houfe. 
“ As the pafte retains a certain degree of humidity, 
it does not admit of granulation immediately on being 
brought from the mill; and is therefore allowed to re¬ 
main two or three days in the graining-houfe before this 
operation commences. The granulation is performed 
by putting the dried matter into a fieve, of which the 
holes are in proportion to the lize we wiffi to give to the 
grains. It is then covered with a piece of hard wood, 
from feven to eight inches in diameter by two in thick- 
nefs, to which a rotatory motion is given, by moving 
the fieve upon a bar placed acrofs a large velfel, into 
which the grains fall : that which is intended to be 
formed into minute grains, is ufually prepared by firft 
foruifing it in a fieve, the holes of which are three lines 
in diameter. They afterwards form the different kinds 
of grains, fuch as the war-grain for cannon, the mujket- 
grain, the fine-grain for fowling-pieces, and the fupcrfinc- 
grain for piftois, by employing lieves having holes of 
different diameters. The powder which remains, after 
the reparation of the grains, is moiftened and again 
beaten for two or three hours. 
“When the granulation is finifhed, it is dried in the 
open air by fpreading it on tables covered with linen 
cloths. It is turned feveral times a-day, and allowed 
to remain in this iituation until it be completely dr.y. 
In the preparation of the fowler’s powder, the pafte is 
only expofed to the air until it lofes part of its humidi¬ 
ty, and in this ftate 150 pounds of it are put into calks 
which revolve round their axis, and which are crofted 
by four bars parallel to the axis. The flow and con¬ 
tinued motion thus communicated to them, produces a 
degree of fridtion which deftroys the afperities of the 
grains, ( and imparts to them a beautiful luftre. After 
having thus polilhed the powder, it is expofed until 
perfedtly dry. It is then agitated in a fieve, in order 
to. free it from any duft which may adhere to the fur- 
face of the grains. This laft operation is known among 
workmen under the name of brujhmg. 
“ The fame learned men commillioned by the govern¬ 
ment, who taught our manufadturers the prompt and 
economic method of purifying faltpetre, at the fame 
time turned their attention to the improvement of thofe 
proceffes employed in the formation of gunpowder. The 
l'uccefs of their labours was fo great, that in the fpace 
of a few months fixteen millions of pounds of faltpetre 
were produced in France ; to fuch perfection indeed 
had they brought this art, that in the powder-works at 
.Crenelle alone, thirty-four thoufand pounds were fabri¬ 
cated daily. It is to M.-Carny in particular that Franee 
> W D E H. 
owes the improved methods of making gunpowder. I 
have myfelf introduced fome ufeful alterations in the 
different operations; but to M. Carny muft be folely 
attributed the merit of the difcovery. 
“We may now reduce to three operations, every 
thing that is interefting in this new method of prepar¬ 
ing gunpowder. 1. Pounding and lifting the materials. 
2. Producing an accurate divifion and intimate mixture 
in the cades. 3. Giving to the mixture the requilite 
degree of confidence, and granulating the powder. 
“ The pulverization or grinding of the materials, is 
performed feparately by means of two bronze mill- 
ftones running on the two extremities of the fame axis, 
and turning in a trough. The fame machinery turns at 
the fame time four fieves, through which the pounded 
fubftance is paffed, in proportion as it is taken from the 
.trough. It is neceflary that the fulphur fitould be fine¬ 
ly pulverized. The fame degree of accuracy is not re¬ 
quired in refpedl to the charcoal and the faltpetre ; 
they ought, however, to be carefully dried before be¬ 
ing fubjedled to this operation. When the different 
materials have been fufficiently pulverized, they are 
mixed together in the. requilite proportions, and put 
into calks, or vats, thirty-two inches in length, by twen¬ 
ty-two in width. Thefe vats are folidly conftrudted of 
thick oak planks, and an opening made in one of their 
bottoms, about fix inches fquare, to which a cover is 
adapted, in order to render it more convenient to put 
in and-remove the materials. An iron axis covered 
with wood runs through tire longitudinal diameter of 
thefe veflels; this axis, which projedts at the two ex¬ 
tremities, refts upon a wooden frame, and freely re¬ 
volves upon itfelf; to the two extremities are adapted 
handles, in order to move the calk. Into each of thefe 
veflels are put feventy-five pounds of the compofition;. 
and they perform from thirty-five to forty-five revolu¬ 
tions in a minute. The mixture and trituration of the 
materials are greatly affifted, by introducing into every 
one of thefe veflels eighty pounds of bronze, in fmall 
balls, four lines in diameter ; and by ledges, or mould¬ 
ings, applied to the inner fides of the calk. 
“The compofition is known to be fufficiently pul¬ 
verized, when on a fmall portion of it being fpread over 
a wooden pallet, with the blade of a knife, no rough, 
nefs is perceptible; when the colour is uniform, and 
the knife experiences no refinance on its application to 
the pallet. On the compofition being taken out of the 
pulverizing veflels, the next operation is to give it the 
requifite degree of confidence, to fit it for granulation ; 
and this is performed by ftrong compreflion, and the 
aid of a little water. With this view, fquare pieces, 
of walnut-tree wood are provided, fixteen inches in 
length, by one foot in breadth, furniffied with mould¬ 
ings projecting from five to fix lines. The inferior 
edges of the platters are hollowed out, fo as to corre- 
fpond with the inner angles of thefe mouldings, in order 
that that they may be readily placed within each other, 
“The operation is commenced by covering the bot¬ 
tom of one of the tables with a piece of moiff linen; 
over this is fpread a ftratum of the compofition, which is 
carefully covered with a fimilar piece of wet linen, and 
a lecond platter adapted to it, filled in the fame man¬ 
ner as the firft. In this way, twenty-three platters are 
placed one above the other; the laft of which is cover¬ 
ed with a fquare piece of wood, and a heavy prefs 
ferewed down upon the whole. By this means a hard 
cake is formed, which is broken by the hand, and after 
being dried, is fubjedted to the procefs of granulation. 
It was formerly my opinion, that this operation might 
be equally well performed, by means of a muller made 
to act on the compofition. Experience has, however, 
convinced me, that this laft procefs is in every refpeCt 
preferable to the former. This manner of forming gun¬ 
powder poffefles numerous advantages ; rapidity in the 
execution, economy in the confumption of the mate- 
