IMPROVE MENTS IN THE MANUFACTURE OF GUNPOWDER
Year: 1862

page_text: LETTERS PATENT to John Tonkin, the younger, of Pool, in the Parish of
Illogan, in the County of Cornwall, for the Invention of "IMPROVE
MENTS IN THE MANUFACTURE OF GUNPOWDER."
Sealed the 29th July 1862, and.dated the 6th February 1862.
PROVISIONAL SPECIFICATION left by the said John Tonkin at the Office
of the Commissioners of Patents, with his Petition, on the 6th February
1862..
I, JOHN TONKIN,. the younger, of Pool,. in the Parish of Illogan, in the
County of Cornwall,. do hereby declare the nature of the Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF GUNPOWDER," to be as follows:-
This Invention has for its object improvements in the manufacture of gun--
powder For this purpose I mix together as heretofore charcoal, sulphur,.
and nitre or nitrate of soda, and to this mixture I add fibre, preferring
vegetable fibre, previously treated to convert it into gun cotton or a substance-
analogous thereto. I reduce the prepared fibre to a pulp, such as is used
by paper makers; and this pulp' I mix with the charcoal, sulphur, and
nitre or nitrate of soda so as to produce a dough, this dough I place in a
cylinder or vessel, beneath which an endless apron passes, the apron is by a
roller kept so closely up to the bottom of the cylinder or vessel. as to leave

page_text: only a few small passages between the two, a piston is placed over the dough
in the cylinder or vessel, and is pressed downwards; this in conjunction with
the forward motion of the endless apron causes the compound to issue through
the small passages between the cylinder or vessel and the apron. The small
sticks or rolls of compound whilst still on the apron are cut into short lengths
which are then dried, this being done the manufacture is complete. It should
be stated that this mode of treating the preparation of gunpowder above
described is also applicable to other plastic preparations of gunpowder.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed by
the said John Tonkin in the Great Seal Patent Office on the 5th August
1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
TONKIN, the younger, of Pool, in the Parish of Illogan, in the County of
Cornwall, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her. Letters
Patent, bearing date the Sixth day of February, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Tonkin, IIer special licence that I, the said John Tonkin,
my executors, administrators, and assigns, or such others as I, the said
John Tonkin, 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, exer-
cise, and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF GUNPOWDER," upon the condition (amongst others) that I, the
said John Tonkin, 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 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.
the
NOW KNOW YE, that I, the said John Tonkin, do hereby declare.
nature of the said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following state-
ment thereof; that is to say:-

page_text: This Invention has for its object improvements in the manufacture of gun-
powder. For this purpose I mix together as heretofore, charcoal, sulphur.
and nitre or nitrate of soda. I prefer to proceed as follows:-I take of
saltpetre, or nitrate of soda 56 lbs., charcoal 26 lbs., sulphur 15 lbs., and
reduce them separately to dust by the ordinary process of grinding, then I
mix the three ingredients together in a cylinder supplied with a number of
wooden or other balls which is caused to revolve until the materials are
intimately mixed. To this mixture I add fibre, preferring vegetable fibre,
previously treated to convert it into gun cotton or a substance analogous
thereto. In preparing the fibre I prefer to proceed as follows:-I first take
the "fibre," preferring cotton fibre as clean as possible, and quite dry, the
acids I employ are nitric acid of from 145 to 1.50 specific gravity, and
sulphuric acid 1.85 specific gravity, and I take one measure of the nitric
acid, and three measures of the sulphuric acid, I then pour the acids in a
convenient vessel of glazed earthenware, glass or other material not acted
on by the acids. By this admixture great heat will be produced, the mixture
should be allowed to cool until it reaches a temperature of from 60 to 50
degrees Fahrenheit, the fibre or cotton should then be immersed in the acids so
mixed so as to become thoroughly impregnated therewith. It should be intro-
duced as open as practicable. And in order to ensure the cotton being fully
impregnated with the acids, and every part equally and fully subjected to the
action thereof, the cotton when in the acids is to be moved or stirred by means
of a rod of glass or other matter not acted on by the acids. The acids aro
then to be poured or drawn off. The cotton is to be gently pressed in the vessel
containing it, by a presser of glazed earthenware or other material, in order
to free it in part from the acids, and is next to be covered and left to stand
for about an hour when it is again to be pressed in order to remove as minch
of the acids therefrom as practicable, after which the cotton is to be washed
in a continuous flow of water and well agitated or stirred therein till the
water does not indicate the presence of any acid by the ordinary test of
litmus paper, the cotton is now again to be pressed to free it from the water
as much as practicable, and in order to ensure the cotton being perfectly
freed from uncombined acid it is to be dipped in a very weak solution of
carbonate of potash. The solution which I use for this purpose is in the
proportion of one ounce of carbonate of potash to one gallon of water. I
now take, the fibre while it is in a wet state and convert it into pulp in the
same manner as is practised by paper makers, by putting the fibre into a
cylinder having knives revolving rapidly working close to fixed knives. This
pulp I mix with the charcoal, sulphur, and nitre or nitrate of soda so as to

page_text: produce a dough. To the quantity of these ingredients above mentioned
'I add 3 lbs. of prepared pulp with a sufficient quantity of water to form
the whole into a paste or dough, which I cause to be treated under mill
runners (as commonly used) until the mixture is complete. This dough
I place in a cylinder or vessel beneath which an endless apron passes, the
apron is by a roller kept so closely up to the bottom of the cylinder or vessel
as to leave only a few small passages between the two. A piston is placed
over the dough in the cylinder or vessel and is pressed, downwards, this
in conjunction with the forward motion of the endless apron causes.the
compound to issue through the small passages between the cylinder or vessel
to the apron. The small sticks or rolls of compound, whilst still on the
apron are cut into short lengths which are then dried, this being done the.
manufacture is complete.
The Drawing hereunto annexed shews a'machine such as above described.
Figure 1, is a vertical section, Figure 2, an end view, and Figure 3 a portion.
of a plan thereof. The dough after being taken from the mill runners is,
introduced in the cylinder or vessel M through a moveable. slide O which is:
withdrawn for the introduction of the dough and afterwards replaced, the,
dough is then forced by a pressure exerted on the piston N on to the apron or;
band A, which by its forward motion and the downward pressure of the piston
causes the paste or dough to issue through the passages of the die E in long.
strips; below the dio is fixed a wire cylinder which is pressed against the.
apron by springs; as the strips are carried down by the motion of the apron.
they are cut into pieces or grains of the proper length by the wire cylinder.
which revolves by the friction of its pressure against the moving apron; the.
distance of the wires from each other in the wire cylinder L regulates the.
length of the grain; the grains then fall into the drawer J which when full.
is removed to the drying house, and when the powder is sufficiently dry the
manufacture is completed. The apron or band A is made by preference of
vulcanized india-rubber, this being elastic does not press the grains of powder.
too hard and therefore makes the powder lighter than if pressed. between
metal or wood only.
It should be stated that the mode of treating the preparation of gunpowder
above described to divide it into grains is also applicable to other plastic pre-
parations of gunpowder.
I would remark that it is not essential to convert the fibre, employed into
gun cotton, and that by mixing fibre with the ingredients, ordinarily employed
in the manufacture of gunpowder a compound is obtained which may be gran-
ulated in the ordinary manner, with less waste than would otherwise be made.

page_text: Should I use the fibre without converting it into gun cotton, the following
would then be the proportions. I should prefer :-
Nitre or nitrate of soda
Charcoal
Sulphur
Fibre converted into a pulp
lbs.
65
16
16
3
100 lbs.
I, however, prefer to convert the fibre in the manner herein-before fully
described.
Having thus described the nature of my Invention, and the manner of
performing the same, I would have it understood that what I claim is,―
First, the manufacture of gunpowder, of a compound of charcoal, sulphur,
and nitre or nitrate of soda, with vegetable fibre converted into gun cotton,
or a substance analogous thereto.
Second, I claim generally the manufacture of gunpowder of a compound of
charcoal, sulphur, and nitre, or nitrate of soda with fibre.
Third, I claim the granulating gunpowder by means of a machine consisting
of an expressing cylinder or vessel combined and working in conjunction with
a die and endless apron as described.
In witness whereof, I, the said John Tonkin, have hereunto set my hand
and seal, this Thirty-first day of July, in the year of our Lord One
thousand eight hundred and sixty-two.
JOHN TONKIN. (L.S.)