IMPROVEMENTS IN IN MECHANISM REQUIRED FOR AND IN THE MANUFACTURE AND COMPOSITION GUNPOWDER
Year: 1861

page_text: LETTERS PATENT to William Bennetts, of Tucking Mill, Camborne, in
the County of Cornwall, Engineer, for the Invention of "IMPROVEMENTS IN
LETTERS PATENT to William Bennetts, of Tucking Mill, Camborne, in
the County of Cornwall, Engineer, for the Invention of "IMPROVEMENTS IN
IN
MECHANISM REQUIRED FOR AND IN THE MANUFACTURE AND COMPOSITION
GUNPOWDER."
Sealed the 13th June 1862, and dated the 21st December 1861.
PROVISIONAL SPECIFICATION left by the said William Bennetts at
the Office of the Commissioners of Patents, with his Petition, on the
21st December 1862.
I, WILLIAM BENNETTS, of Tucking Mill, Camborne, in the County of
Cornwall, Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE MECHANISM REQUIRED FOR AND IN THE MANUFACTURE
AND COMPOSITION OF GUNPOWDER," to be as follows:-
The ingredients consist of lime, nitre, sulphur, and charcoal. The lime is
dissolved in a sufficient quantity of water to bring the other ingredients into a
paste. The lime, after having been made into a solution, is strained through
a fine seive; this solution is added to the other ingredients. The whole is
then put into a mill and ground until it becomes a paste. It is then taken
out of the mill and passed between two rollers; one roller is grooved, the
other is plain. The powder by passing between the rollers is formed into long

page_text: strips of a triangular shape. It is then carried on an endless web or canvass
over some hot tubes, which are heated by steam, hot water, or any other
artificial heat which may be applied. By this means the powder is easily
broken into grains. This mode of manufacture prevents a great deal of
danger, as the powder is pulverized and brought into grains while in a wet
state. The lime makes a firm grain, and resists the damp, and gives it a certain
degree of lightness, which increases the bulk twenty-five per cent. over
ordinary gunpowder, which is a great advantage for blasting purposes. Plaster
of Paris, blue lias, Roman or Portland cement, or other strong cementing
substance may be used as a substitute for lime. And I find that for blasting
purposes the following proportions answer very well, viz., nitre 65 parts;
charcoal, 18; sulphur, 10, and lime, 7; but the proportions vary according to
the strength required.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Bennetts in the Great Seal Patent Office on the
19th June 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
BENNETTS, of Tucking Mill, Camborne, in the County of Cornwall, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of December, in the year of our
Lord One thousand eight hundred and sixty-one, in the twenty-fifth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said William Bennetts, Her special licence that I, the said William
Bennetts, my executors, administrators, and assigns, or such others as I,
the said William Bennetts, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN THE MECHANISM REQUIRED FOR AND IN THE MANUFACTURE AND COM-
POSITION OF GUNPOWDER," upon the condition (amongst others) that I, the said
William Bennetts, my executors or administrators by an instrument in
writing under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention and in what manner

page_text: the same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Bennetts, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement, that is to say:-
The ingredients consist of lime, nitre, sulphur, and charcoal. The lime is dis-
solved in a sufficient quantity of water to bring the other ingredients into a paste.
The lime, after, having been made into a solution, is strained through a fine
sieve; this solution is added to the other ingredients. The whole is then put
into a mill and ground until it becomes a paste. It is then taken out of the
mill and passed between two rollers; one roller is grooved, the other is plain.
The paste by passing between the rollers is formed into long strips of a
triangular shape; it is then carried on an endless web or canvass over some
hot tubes, which are heated by steam, hot water, or any other artificial heat
which may be applied. By this means the strips are easily broken into grains.
This mode of manufacture prevents a great deal of danger, as the powder is
pulverized and brought into grains while in a wet state. The lime makes a
firm grain and resists the damp, and gives it a degree of lightness which
increases the bulk 25 per cent. over ordinary gunpowder, which is a great
advantage for blasting purposes. Plaster of Paris, blue lias, Roman or
Portland cement, or other strong cementing substance may be used as a sub-
stitute for lime. And I find that for blasting purposes the following proportions
answer very well, viz., nitre 65 lbs. ; charcoal, 18; sulphur, 10, and lime, 7;
but the proportions vary according to the strength required.
Having thus described the nature of my Invention, I will proceed to
describe more fully the manner of performing the same.
In manufacturing gunpowder according to my Invention the lime is, as
above stated, first dissolved or mixed with sufficient water to bring the other
ingredients into a paste; this, when the above ingredients are used, will
require about 16 lbs. of water. And I find that by first placing the lime in a
dry place until it becomes air-quenched before dissolving or mixing it with
water, that the combustion of the powder is greatly increased; and when the
lime is first air-quenched it will only require to be mixed with about 10 lbs. of
water when the above quantities are used. The solution of lime is strained
through a fine sieve, and the other materials are then added to it, and the
whole is put into a mill and ground into a paste. When I use plaster of

page_text: Paris or other cementing material in place of lime, I employ them in the same
proportions, and in the same manner as when using lime.
I now proceed more fully to describe the second part of my Invention, which
relates, as above mentioned, to the forming powder into grains while in a
damp or plastic state by means of suitable roller apparatus.
Fig. 1 of the Drawings hereunto annexed is a side elevation of a machine
for pressing powder into grains by means of rollers, according to my Inven-
tion; Fig. 2 is ground plan of the same.
A, A, is the wood frame which carries the graining rollers E and F ; B is a
toothed wheel fixed on one end of the grooved roller E. This wheel gears with
a toothed pinion, on the axis of which is a pulley C driven by a strap or band
on the opposite end of the roller; E' is a toothed wheel which gears with
another toothed wheel on the axis of the plain roller F; D is the hopper or
funnel, into which is placed the powder in a plastic state. On motion being
given to the rollers E and F, the powder in the hopper or funnel will be by
them formed into strips, which will be received on trays G, having wooden
sides, with canvass or metal bottoms. These frames are carried by the endless
cords over the hot pipes I, which may be heated by steam, hot water, or
any other artificial heat. The cords are distended between the drums K, L,
and the drum K is caused to rotate so as to move forward, the trays resting
on the cords at the same surface speed as the graining rollers by a toothed
wheel on the drum K gearing with a pinion M on the roller F. As the trays
arrive at the drum L they are taken off the cords and placed in a rack J over
the heated pipes. The strips of powder, when dry, are placed in a brass-
bottomed sieve, together with wooden balls; the sieve is then put into motion,
which causes the balls to roll over the powder. When the strips are broken
into grains of a suitable size the grains pass through the sieve, the holes of the
sieve being made of the size of the grain required. In place of first forming
the powder into strips; and afterwards breaking up the strips when dry into
grains, the paste may be made at once into grains of powder by the rollers, by
making the plain roller F of larger diameter than the grooved roller E, so that
the surface speed of the plain roller will be greater than the surface speed of
the grooved roller, and by placing at intervals around the smooth roller F
small projections to enter the grooves in the roller E, the grains as they are
produced by the rollers will be received on the endless belt, and be dried as
before described. When it is desired to make the grains of powder hollow,
then I place a stationary wire in the centre of each groove of the graining
roller.

page_text: Having thus described the nature of my Invention, and the best means
I am acquainted with for carrying the same into effect, I would have it under-
stood that what I claim is,-
First, the combining lime, or blue lias, plaster of Paris, Roman or Portland
cement, or other like strong cementing material with the other substances.
Secondly, the improvement in the process of manufacturing gunpowder,
consisting in the employment of roller apparatus, as herein-before described,
for forming the paste when in a plastic state into grains.
Thirdly, the combination of mechanism herein described for forming paste
into grains of powder.
In witness whereof, I, the said William Bennetts, have hereunto set.
my hand and seal, the Seventeenth day of June, in the year of our
Lord One thousand eight hundred and sixty-two.
WILLIAM BENNETTS. (L.s.)