IMPROVEMENTS IN THE MANUFACTURE OF EXPLOSIVE COMPOUNDS, and in THE APPARATUS USED IN SUCH MANUFACTURE
Year: 1873

page_text: LETTERS PATENT to Samuel Josephi Mackie, of No. 3, Delahay Street,
Great George Street, in the City of Westminster, for the Invention
of "IMPROVEMENTS IN THE MANUFACTURE OF EXPLOSIVE COMPOUNDS, and in
THE APPARATUS USED IN SUCH MANUFACTURE.”
Scaled the 15th July 1873, and dated the 6th February 1873.
PROVISIONAL SPECIFICATION left by the said Samuel Joseph Mackic
at the Office of the Commissioners of Patents, with his Petition,
on the 6th February 1873.
I, SAMUEL JOSEPH MACKIE, of No. 3, Delahay Street, Great George
Street, in the City of Westminster, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF EXPLOSIVE
COMPOUNDS, AND IN THE APPARATUS USED IN SUCH MANUFACTURE," to be as
follows:-
In order to steep cotton pulp or cotton waste more or less disintegrated
in an acid bath to convert it into gun cotton I use a machine consisting
of a large tank surrounded by a hopper, into which the cotton pulp, or
cotton wast, or cotton powder dried or more or less moist is introduced,

page_text: and from thence led into the tank. The tank is so arranged that the
acid is introduced at the point where the cotton falls in, and a stirrer or
immersing wheel causes the cotton to be quickly immersed. As the
stirrer revolves it pushes away this pulp with the acid it contains and
these are taken out of the tank and put into pots, the tank having
special openings so as to fill theso pots in any number at a time. The
digesting pots are arranged into a cradle in series of 7 or 8 at a time, or
more or less, and form a whole that can be brought by means of a
traveller overhead, or otherwise, either to the steeping tank or tanks
and from thence be deposited into the cooling pond, or be carried to a
trough in communication with the centrifugal apparatus used for
separating the acid at the other end of the pond.
In order to free gun cotton from acid I pass it between pressing rollers
to express the acid from it. The process of cleansing may be carried
stiil further by passing the gun cotton into water and subsequently
again passing it between rollers, repeating this process as often as
necessary.
In order to be enabled to mix or incorporate any definite quantity of
crushed or powdered gun cotton or gun cotton pulp or material during
the process of its manufacture into cotton gunpowder with other
ingredients without drying the gun cotton I employ a machine that will
give the weight of any wet bulk of gun cotton in figures representing
the weight of the dry gun cotton contained in the mass. To that effect
I use a receptacle or bottle arranged so as to receive the material casily
and deliver it casily and also to allow the air to escape promptly from
within as the wet gun cotton is introduced, the neck of the bottle, is
perforated at a certain level so as to allow the water level to be always
constant, the water being free to run out as through an overflow. This
bottle is suspended upon a weighing apparatus adapted to the purpose,
and the action is such that the specific gravity of the substance in
suspension in the water being known, as well as the contents of the
bottle up to the perforations in the neck, it is casy by reference to the
weights that counterbalance the contents of the bottle to ascertain
the weight of their contents when dry.
In order to granulate plastic compounds of gun cotton I use a cylin-
drical screen and caused to revolve upon its axis. [The pasty substance
is introduced within and by the action of the screen, and if desired aided
by a current of air, the pulp or paste is caused to pass out through the

page_text: meshes in small lumps; these are received into another similar screen
with smaller perforations or meshes, and acquires then a more decided
form and compactness; a third screen or plain cylinder receives the
grains from the second screen, but the air is slightly warm and causes
the grains to dry as they are rotated. The cylinder or screen may be
used to subsequently act upon the grains until the grains are sufficiently
hard to be removed.
In some cases also to form cotton gunpowder in a plastic state into
granules I place layers of such material between indented plates of
metal and compress the whole in an hydraulic or other press.
In order to give any desired density to cotton gunpowder which has
been reduced into granules I employ an apparatus which I call a fluid
condenser to give the grains a uniform density. This consists of a strong
vessel containing mercury or other fluid; into this vessel I also introduce
a given weight of the grains or pieces, and by means of a plunger or
presser, or otherwise I force the whole contents of the vessel to occupy
a given space, thereby compressing the grains into a given volume
having a given density.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Samuel Joseph Mackie in the Great Seal Patent
Office on the 6th August 1878.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SAMUEL
Josepii Mackie, of No. 3, Delahay Street, Great George Street, in the
City of Westminster, 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 seventy-three, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Samuel Joseph Mackie, Her special license
that I, the said Samuel Joseph Mackic, my exccutors, administrators,
and assigns, or such others as I, the said Samuel Joseph Mackie, my
executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thercafter during
the term therein expressed, should and lawfully might make, use,

page_text: "
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IM-
PROVEMENTS IN THe Manufacture oF EXPLOSIVE COMPOUNDS, AND IN THE APPARATUS
used in such Manufacture," upon the condition (amongst others) that I,
the said Samuel Joseph Mackic, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
scals, 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.
NOW KNOW YE, that I, the said Samuel Joseph Mackic, do hereby
declare the 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 statement thereof, that is to say :—
In order to steep cotton pulp or cotton waste more or less dis-
integrated in an acid bath to convert it into gun cotton I use a machine
consisting of a large tank surmounted by a hopper, into which the cotton
pulp, or cotton waste, or cotton powder dried, or more or less moist, is
introduced and from thence led into the tank. This tank is so arranged
that the acid is introduced at the point where the cotton falls in, and a
stirrer or immersing wheel causes the cotton to be quickly immersed.
As the stirrer revolves it pushes away this pulp with the acid it contains,
and these are taken out of the tank and put into pots, the tank having
special openings so as to fill these pots in any number at a time.
Figure 1 shows a longitudinal vertical section and Figure 2 a
transverse vertical section of a machine constructed as above described.
a is a hopper into which the cotton pulp or waste is introduced, is a
spiked roller at the bottom of the hopper. A slow revolving motion is
given to this roller and it delivers the cotton continuously and uniformly
into the tank c just where the acid is introduced into the tank through
the pipe d. Just below the mouth of this pipe is a fixed grating e along
which the cotton travels and is caught by the blades of the immersing
wheel, by which the cotton is quickly immersed and is propelled to
the opposite end of the tank where it can from time to time be drawn
off through the pipe g into digesting pots. The digesting pots as they
are filled are placed into a cradle as shown at Figures 3 and 4 in series

page_text: of 7 or 8 at a time, or more or less, and form a whole that can be brought
by means of a traveller overhead, as shewn in the Drawing, either to the
sleeping tank or tanks and from thence be deposited into the cooling
pond or be carried to a trough in communication with the centrifugal
apparatus used for separating the acid at the other end of the pond, the
overhead traveller enabling the cradle to be readily raised and lowered
into or out of the tank, or the cradle can be swung round its suspension
point so as to tip the contents of the pots into the troughs whence they
are put into the centrifugal or hydro-extractor.
In order to free gun cotton from acid I pass it between prossing
rollers to express the acid from it. The process of cleansing may be
carried still further by passing the gun cotton into water and sub-
sequently again passing it between rollers, repeating this process as often
as necessary.
In order to be enabled to mix or incorporate any definite quantity of
crushed or powdered gun cotton or gun cotton pulp or material during
the process of its manufacture into cotton gunpowder with other
ingredients, without drying the gun cotton, I employ a machine that
will give the weight of any wet bulk of gun cotton in figures,
representing the weight of the dry gun cotton contained in the mass.
To that effect I use a receptacle or bottle arranged so as to receive the
material easily as well as deliver it easily and allow the air to escape
promptly from within, as the wet gun cotton is introduced. The neck
of the bottle is perforated at a certain level so as to allow the water level
to be always constant, the water being free to run out as through an
overflow. This bottle is suspended upon a weighing apparatus adapted
to the purpose, and the action is such that the specific gravity of the.
substance in suspension in the water being known as well as the con-
tents of the bottle up to the perforations in the neck, it is easy, by
reference to the weights that counterbalance the contents of the bottle,
to ascertain the weight of these contents when dry.
At Figure 4 I have shewn an apparatus constructed in this manner.
a is the receptacle or bottle mounted at one end of a scale beam 6, upon
the opposite end of which is suspended a weight to counterbalance the
5 receptacle when filled with water and also the quantity of gun cotton to
be weighed out at each weighing. c is a hopper at the top of the open
mouth of the bottle or receptacle to facilitate the introduction of wet
gun cotton into it; d, d, are openings in the neck by which water is

page_text: frco to overflow. Any water flowing out through these openings is
conducted away by the spout e. f is a valve at the bottom of the
receptacle by which its contents may readily be discharged.
The operation of weighing is as follows:-The receptacle being filled
with water the wet gun cotton or the substance to be weighed is
introduced into it, so displacing an equal volume of water which flows
away by the overflow at the neck, and the cotton is added little by little
until the weight at the opposite end of the beam is balanced. The
contents of the receptacle are then discharged into any suitable vessel and
are conveyed away.
The weighing apparatus, independent of the bottle, can be constructed
on spring, lever, or other principle usually adopted for weighing.
In order to granulate plastic compounds of gun cotton I use a
cylindrical screen caused to revolve upon its axis. The pasty substance
is introduced within and by the action of the screen and, if desired,
aided by a current of air the pulp or paste is caused to pass out
through the meshes in small lumps; these are received into another
similar screen with smaller perforations or meshes and acquire thus a
more decided form and compactness. A third screen or plain cylinder
receives the grains from the second screen, but the air is slightly warm
and causes the grains to dry as they are rotated. Other cylinders or
screens may be used to subsequently act upon the grain until the
grains are sufficiently hard to be removed.
In some cases also to form cotton gun powder in a plastic state or
otherwise into grains, I place layers of such material between indented
plates of metal and compress the whole in a hydraulic or other press.
The pressure required to form grains in this manner varies from 1 ton
to 10 tons upon the square inch. Both plates may have indentations or
one may have indentations and the other may be smooth. The form of
the indentation corresponds to the required form of grain.
In order to give any desired density to cotton gun powder which has
been reduced into granules, I employ an apparatus which I call a fluid
condenser to give the grains a uniform density. This consists of a
strong vessel containing mercury or other fluid. Into this vessel I also
introduce a given weight of the grains, and by means of a plunger or
presser or otherwise I force the whole contents of the vessel to occupy a