IMPROVEMENTS IN THE MANUFACTURE OF EXPLOSIVE COMPOUNDS FOR MINING AND OTHER PURPOSES
Year: 1874

page_text: LETTERS PATENT to Camille Alphonse Faure, of S, Montford Place,
in the Parish of Lambeth, London, Eugincer, and George Trencli,
of Broomfield House, in the Parish of Oare, in the County of Kent,
Engineer, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE
"
PROVISIONAL SPECIFICATION left by the said Camille Alphonse Faure
and George Trench at the Office of the Commissioners of Patents,
with their Petition, on the 2nd November 1874.
We, CAMILLE ALPHONSE FAURE, of 8, Montford Place, in the Parish
of Lambeth, London, Engineer, and GEORGe Trench, of Broomfield
House, in the Parish of Oare, in the County of Kent, Engineer, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF EXPLOSIVE COMPOUNDS FOR MINING AND OTHER PURPOSES,"
to be as follows :-
In order to explain the nature and aim of the said Invention, we
submit that two well known and different effects of less or greater

page_text: violence, respectively, can be obtained from any explosive, according to
the methods employed to cause the explosion.
One method is by contact with a flame or spark or an ordinary per-
cussion cap or fire producer, and in which case the effect of the explosion
depends upon the rate of ignition of the explosive, and is of a com-
paratively small degree of violence.
A second method is caused by detonation by means of a cap filled
with fulminate of mercury to such an extent that the initial pressure
given by the explosion to this fulminate of mercury is sufficient to
expend such energy or work within the substance to be exploded, that
the resulting increase of temperature within the said substance is equal
or superior to that which corresponds to the natural exploding point of
the said substance. This method produces a comparatively greater
degree of violence.
We submit also that any known explosive can be treated by this
second method provided that a priming charge or cap be applied, which
by its qualities and quantities is sufficiently powerful to correspond with
or overcome the refractory power which the explosive substance has to
resist this method of explosion.
Now our Invention has for its object the making of an explosive com-
pound and of explosive mining charges that cannot be or are not under
ordinary circumstances liable to be exploded by any of the means that
we have described as belonging to the first method, or that will have a
strong tendency to resist being so exploded, from the circumstance that
it is difficult for it or them to catch fire, and also from the circumstance 2
that this explosive being contemplated to be used in the form of very
large grains or mass or masses, the surface that such explosive presents
to ignition is very limited. The above feature is intended to insure
safety, the explosive quality depending solely on the means employed,
according to the method secondly above described. To this effect we 3
mix or incorporate together one part of charcoal with sixteen parts of
nitrate of baryta, and one part of nitro cellulose. This mixture is then
compressed into discs or blocks of such form as will best fit any form of
bore hole in mining, or of any vessel to be burst asunder. In the centre
of these discs or blocks we fix the sufficiently powerful powerful priming 3
charge, so that the mixture may completely surround it, excepting at a
hole through the centre of the discs, made for the insertion of an ordinary

page_text: or approved fuse and detonator. The said priming charge is a small
cartridge containing about half an ounce of gun cotton.
The making of these discs, together with the insertion of the priming
charge and making the central hole is effected at one operation in the
following manner :-A strong cast-iron vessel is bored to the size of the
intended disc, and is fitted with a bottom disc carrying a central pin of
same diameter as the central hole requires. Upon and around this pin
is fixed the priming cartridge, and the surrounding space is then filled
with the mixture above described, and a piston is then brought to bear
upon the substance by means of hydraulic pressure.
When it is desired to use (explode) a disc or block the fuse and deto-
nator are to be applied at the time.
Although the above mixture and subsequent operations are what we
consider best, we wish it to be understood, that we may vary them to
some extent either in substance, proportion, manner of packing or
pressing the materials together, and ultimate shape. For instance, the
charcoal can be replaced totally or in part by any combustible substance,
such as sawdust, or paraffin, or the like. The oxidising substance can
be replaced totally or in part by the nitrates of soda, or potassa, or
chlorate of potash. The nitro-cellulose is introduced merely to render
the mixture more sensitive to detonation, as it inflames naturally at a
degree of heat lower than that required by charcoal. We can replace
it totally or in part by nitro-glycerine, the fulminates of the metals, or a
compound of pieric acid.
We make also blasting charges by packing together in a wrapper the
explosive mixture and the priming charge, or the two articles may
be sent separately to the bore hole of a mine, and the charge may
be prepared and adjusted therein. In this case, and for convenience,
we make the mixture into grains similar to ordinary gunpowder.
30 SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Camille Alphonse Faure and George Trench in
the Great Scal Patent Office on the 1st May 1875.

page_text: London, Engineer, and GEORGE TRENCH, of Broomfield House, in the
Parish of Oare, in the County of Kent, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of November, in the
year of our Lord One thousand eight hundred and seventy-four, in
the thirty-eighth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto us, the said Camille Alphonse Faure and
George Trench, Her special license, that we, the said Camille
Alphonse Faure and George Trench, our executors, administrators,
and assigns, or such others as we, the said Camille Alphone Faure,
and George Trench, our 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 "IMPROVEMENTS IN THE MANUFACTURE OF EXPLOSIVE COMPOUNDS
FOR MINING AND OTHER PURPOSES," upon the condition (amongst others)
that we, the said Camillo Alphonse Faure and George Trench, our
executors or administrators, by an instrument in writing under our,
or their hands and seals, or under the hand and seal of one of us,
or them, 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 we, the said Camille Alphonse Faure and
George Trench, 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 :-
This Invention has for its object improvements in the manufacture
of explosive compounds for mining and other purposes.
In order to explain the nature and aim of the said Invention we
submit that two well known and different effects of less or greater
violence, respectively, can be obtained from any explosive, according to
the methods employed to cause the explosion,

page_text: One method is by contact with a flame or spark or an ordinary per-
cussion cap or fire producer, and in which case the effect of the explosion
depends upon the rate of ignition of the explosive, and is of a com-
paratively small degree of violence.
A second method is caused by detonation by means of a cap filled
with fulminate of mercury to such an extent that the initial pressure
given by the explosion of this fulminate of mercury is sufficient to
expend such energy or work within the substance to be exploded, that
the resulting increase of temperature within the said subsiance is equal
or superior to that which corresponds to the natural exploding point of
the said substance. This method produces a comparatively greater
degree of violence.
We submit also that any known explosive can be treated by this
second method provided that a priming charge or cap be applied, which
by its qualities and quantities is sufficiently powerful to correspond with
or overcome the refractory power which the explosive substance has to
resist this method of explosion.
Now our Invention has for its object the making of an explosive com-
pound, and of explosive mining charges that cannot be or are not under
ordinary circumstances liable to be exploded by any of the means that
we have described as belonging to the first method, or that will have a
strong tendency to resist being so exploded, from the circumstance that
it is difficult for it or them to catch fire, and also from the circumstance
that this explosive being contemplated to be used in the form of very
large grains or mass or masses, the surface that such explosive presents
to ignition is very limited. The above feature is intended to insure
safety, the explosive quality depending solely on the means employed
according to the method secondly above described. To this effect we.
mix or incorporate together one part of charcoal, with eight parts of.
nitrate of baryta, and one part of nitro-cellulose. This mixture is then
compressed into discs or blocks of such form as will best fit any form of
bore hole in mining or of any vessel to be burst asunder. In the centre
of these discs or blocks we fix the sufficiently powerful priming charge
so that the mixture may completely surround it, except at a hole
through the centre of the discs made for the insertion of an ordinary or.
approved fuse and detonator. The said priming charge is a small
cartridge containing about half an ounce of gun cotton.
The making of these discs together with the insertion of the priming

page_text: charge, and making the central hole, is effected at one operation in the
following manner :-A strong cast-iron vessel is bored to the size of the
intended disc, and is fitted with a bottom disc carrying a central pin
of same diameter as the central hole requires. Upon and around this
pin is fixed the priming cartridge, and the surrounding space is then
filled with the mixture above described, and a piston is then brought to
bear upon the substance by means of hydraulic pressure.
When it is desired to use (explode) a disc or block the fuse and
detonator are to be applied at the time.
Although the above mixture and subsequent operations are what we
consider best, we wish it to be. understood, that we may vary them to
some extent, either in substance, proportion, manner of packing or
pressing the materials together, and ultimate shape. For instance, the
charcoal can be replaced totally or in part by any combustible
substance, such as sawdust, or paraffin, or the like. The oxidising
substance can be replaced totally or in part by the nitrates of soda, or
potassa, or chlorate of potash. The nitro-cellulose is introduced merely
to render the mixture more sensitive to detonation, as it inflames
naturally at a degree of heat lower than that required by charcoal.
We can replace it totally or in part by nitro-glycerine, the fulminate of
the metals, or a compound of picric acid.
Wo make also blasting charges by packing together in a wrapper
thic explosive mixture and the priming charge, or the two articles may
be sent separately to the bore hole of a mine, and the charge may be
prepared and adjusted therein. In this case and for convenience, we
make the mixture into grains similar to ordinary gunpowder.
In order that our said Invention may be most fully understood and
readily carried in effect, we will proceed to describe the Drawings here-
unto annexed.

page_text: bottom to this mould having a polished and somewhat taper pin b' fixed
in the centre; c is a priming charge of compressed gun cotton, which is
placed upon the pin 6' before the bottom bis inserted in the mould a.
The mould is then filled with the powder before described, made by
mixing together, by preference, charcoal, nitrate of baryta, and nitro-
cellulose, but as before stated, there are other analogous ingredients
which may be employed. The whole is then submitted to a heavy
pressure, say of several tons to the square inch, in an hydraulic press,
and so a block is formed which is not casily broken or easily fired, the
priming charge being surrounded by a material which under ordinary
circumstances is inert. The removal of the peg ¹ leaves a hole for the
insertion of an ordinary mining charge armed with a percussion cap
charged with fulminate of mercury. When the charge is fired by means
of the fuse it detonates with great force, the cap having sufficient power
to detonate the priming cartridge c, and this in turn detonates the com-
paratively inert composition around it.
It is not essential, although very convenient and advantageous, that
the comparatively inert composition should be compressed around the
priming charge, as the two may be placed together in a bag cartridge
with. the priming charge in the midst of the comparatively inert
material, as is shown in elevation at Figure 6, and in section at
Figure 7.