IMPROVEMENTS IN GETTING COAL AND OTHER MINERALS, BLASTING OR DISINTEGRATING ROCK, AND IN THE APPARATUS TO BE EMPLOYED THEREIN, PARTS OF WHICH APPARATUS ARE ALSO APPLICABLE FOR OTHER PURPOSES
Year: 1876

page_text: LETTERS PATENT to James Macnab, of Charlotte Street, Fitzroy Square, in
the County of Middlesex, for the Invention of "IMPROVEMENTS IN GETTING
COAL AND OTHER MINERALS, BLASTING OR DISINTEGRATING ROCK, AND IN THE
APPARATUS TO BE EMPLOYED THEREIN, PARTS OF WHICH APPARATUS ARE ALSO
APPLICABLE FOR OTHER PURPOSES."
aled the 26th January 1877, and dated the 9th August 1876.
PROVISIONAL SPECIFICATION left by the said James Macnab at the Office
of the Commissioners of Patents on the 9th August 1870.
JAMES MACNAB, of Charlotte Street, Fitzroy Square, in the County of Middlesex.
IMPROVEMENTS IN GETTING COAL AND OTHER MINERALS, BLASTING OR DISIN-
TEGRATING ROCK, AND IN THE APPARATUS TO BE EMPLOYED THEREIN, PARTS OF
WHICH APPARATUS ARE ALSO APPLICABLE FOR OTHER PURPOSES."
My Invention relates to the employment of gunpowder or other inflammable or
non-inflammable explosive material for blasting or disintegrating coal, rock, and
other substances without incurring danger from the flame, smoke, or suffocating
odour from the explosive material employed either in underground workings or
otherwise, whilst at the same time a considerable saving of time is effected in the
operation of blasting.
According to my Invention I employ in combination with a simple boring
apparatus for boring the blasting holes a metallic plug containing the explosive
material, which plug is inserted and held securely in the hole during the time of the
explosion by wedges or otherwise. This plug consists of a hollow cylinder or tube
having fitted to its rear end a conical or circular wedge-shaped or other suitable
formed breech piece provided with a chamber or recess for the reception of the
gunpowder or other explosive material. This chamber is separated from the
cylindrical bore of the plug by a moveable disc or plug of wood, cork, or other
suitable material inserted in or forced against the end of the bore next the breech
chamber. The opposite or muzzle end of the cylinder is fitted with a conical
shield, the external diameter of which is equal to that of the cylinder, whilst the
internal diameter of the bore formed in the shield is less than that of the bore of
the cylinder. Upon this conical shield, and extending to about half way up the
same, there is fitted a lead or other soft metal collar for the purpose of preventing
the escape of the gases when the explosion occurs, and is suitable when working

page_text: hard minerals or rocks, but when working coal I prefer to employ a conical spring
steel collar, which is caused to expand and slide up the conical shield and jam
itself into the coal by the force of the explosion acting upon a metal disc or washer
fitted behind the spring collar, thereby making an air and water tight joint around
the external diameter of the muzzle end of the cylinder.
The outer end of the breech piece is made to project and form a circular head of
less diameter than the other part of the breech piece, and in this projecting portion
a chamber is provided to receive an ordinary percussion gun lock and trigger, which
lock is enclosed in the chamber by a screw plug. This chamber is in communi-
cation with the explosive chamber through a vent hole in connection with the
nipple of the gun lock.
The hammer or the trigger of the gun lock is acted upon so as to discharge the
explosive material by means of a spring bolt consisting of a strip of spring steel or
other suitable metal folded or doubled up so as to form a bow on the contre portion
thereof, which bow is passed around a vertical piu fitted to the apparatus. The
ends or arms of this spring bolt are each provided with a hole, which engage with
pins carried either on the hammer or on the trigger, or on a piece fitted thereto in
such a manner as that when the trigger or the hammer, as the case may be, is
pulled out to its full extent by means of a line or wire connected to the bowed
portion of the bolt, the arms thereof will, by pressing against the vertical pin, be
caused to open out and so release or disengage the pins on the trigger rod or
hammer which will then effect the discharge of the cap placed on the nipple of the
gun lock and explode the contents of the chamber.
In the centre of the bowed portion of the spring bolt there is fitted an eye, to
which one end of the trigger line or wire is attached, the opposite end of the line
being connected to and wound upon a reel provided with a spiked handle for the
purpose of securing it to the floor of the working or coal face when out of use.
By enclosing the lock in the manner above described the percussion cap is
exploded without being permitted to have any communication with the gaseous or
external atmosphere of the mine or underground working.
For the purpose of supporting the breech end of the plug I form a groove round
the neck near the shoulder of the breech piece for the reception of a ring or a
forked piece of iron or other metal, to which there is bolted a short lever arm or
bar so arranged as to be capable of being adjusted to any desired angle, and when
adjusted to hold the plug securely in the blasting hole by wedging against a
shoreing block or against the opposite face of the working.
In commencing to operate with my improved apparatus I first bore a hole by
means of a parallel sided auger having the cutting portion to a distance of about
twelve inches from the end of smaller size than the remainder in order to drill a
hole having two different diameters.
The drill or auger is provided with a leather washer of larger diameter than the
hole drilled, which washer, as the drill is being withdrawn, opens out and brings with
it the dust, which is conveyed from behind the washer by means of a worm formed
on the drill holder.
The drill holder is provided with a screw thread, which works in a nut fitted so
as to be capable of adjustment on a frame secured in position between the top and
bottom of the working.
The frame carrying the adjustable nut consists of two hollow cylinders or tubes,
each provided with a self-adjusting end piece which take their bearing upon the
bottom and top of the working respectively.
The two hollow cylinders or tubes are respectively provided with a right and
left-hand internal screw thread fitting corresponding threads formed on a vertical
rod or spindle, so that by turning the spindle by means of a lover or otherwise the
hollow cylinders or tubes will be caused to approach nearer to or recede further from
each other, and thereby fix or release the frame according to the direction in which
the spindle is turned.
The hole having been formed in the coal I unscrew the breech piece from the

page_text: cylinder or barrel of the plug, and place in the breech chamber either loose powder,
a cartridge, or other suitable explosive charge. I then insert a plug in the bore of
the cylinder and fill the latter with water or other suitable liquid by means of a
syphon or otherwise, and insert a cork or other suitable plug into the muzzle end
of the cylinder in order to prevent the escape of the water.
The breech piece
containing the explosive charge is then screwed on to the cylinder and the cylinder
inserted into the hole prepared for its reception, the muzzle end of the cylinder
being caused to bear against the shoulder formed by the drill, which, when the
explosion takes place, causes the lead or the spring collar herein-before described, as
the case may be, to jam itself into the coal and thereby prevent the escape of any
of the gas past the plug. The plug having been inserted in the hole is shored up
in order to prevent it from starting out of position by the force of the explosion.
The chamber containing the lock is now removed from the breech, the nipple of
the gun lock capped, and the hammer raised to full cock, after which the chamber
is replaced and the trigger rod and spring bolt adjusted for action. All being now
ready the trigger line is attached to the spring bolt and unwound from the reel,
the firing party retiring from the face of the coal out of danger. The trigger line
is then drawn out until the spring bolt draws the trigger or hammer, as the case
may be, to its full extent, when it becomes disengaged from the spring bolt by the
vertical pin acting upon the arms thereof so as to open them out, when the hammer
will be also released and effect the explosion of the charge contained in the breech
chamber. The elastic gas generated by the explosion will then suddenly expand
and press upon the water contained in the cylinder of the plug, discharging it into
the coal, which it will throw out with more or less force, according to the power of
the charge contained in the plug. The spring collar at the muzzle of the plug will
at the same time be caused by the force of the explosion to slide up the shield and
wedge itself into or between the coal and the muzzle end of the plug, and thereby
prevent the escape of the gas past the plug.
For undercutting or holeing I first drill or bure an ordinary blast hole of the
diameter of the cylinder or barrel of the plug in a horizontal direction in the
broken end foot or side of the coal face or wall at a few inches from the bottom of
the working, and to a depth of about 3 or more feet from the face. In the hole
thus prepared I force the plug by means of the boring tool holder or otherwise
until its circular wedge-shaped breech piece enters the mouth of the hole so as to
fill up any irregularities at that part. The plug is then shored up so as to prevent
it from starting out of position by the force of the explosion and the explosion
effected in the manner herein-before described.
If the block or mass of coal has not been loosened or thrown down by the
explosion, the operation is followed by boring another similar blast hole parallel to
and immediately above the previous one, but at the top of the coal seam, in which
hole a charge is exploded which will cause the block or mass of coal to break away
or be thrown down by the powerful leverage exerted upon it by the second
explosion; or in lieu of boring a second hole parallel to the first the usual well-
known method of drilling one or more holes at the top of the coal face may be
adopted, and operated upon with my hydraulic exploding plug in the manner
herein-before described. Or any desired number of blast holes may be made in a
receding direction from the face of the coal, and an explosion effected in the manner
herein-before described in each hole in succession or alternately, and thus undercut
a large block or mass of coal.
According to another method I drill blast holes near the bottom of the face of the
coal seam at an acute ascending angle, or I drill two blast holes converging to a
point in the interior of the seam, and effect an explosion therein in the manner
herein-before described, which will cause the coal, to be thrown down without
under cutting or holeing.
In some cases the blast hole may be drilled in a descending angular direction and
be charged with water, in which case the explosive force of the powder is caused
to act direct upon the interior of the chamber formed in the coal itself.

page_text: The incandescent vapour or the flame of the ignited gunpowder or other
explosive material is extinguished before it has time to escape from the contracted
muzzle end of the plug, and the stifling smoke and poisonous gas (carbonic acid
gas) are simultaneously absorbed by the water contained in the cylinder, thus the
air of the coal mine is not affected or made impure, and all inflammable and other
danger is completely neutralized.
I prefer to discharge the explosive material by means of the detonating arrange-
ment herein-before described, but it may be effected by electricity or otherwise if
desired.
:
In lieu of employing loose gunpowder as before described a water-tight cartridge
may be placed in the chamber of the breech piece, and connected to the vent hole of
the gun lock by a tube containing powder or by means of a fuse, the cartridge
itself being entirely surrounded by the water contained in the plug; or the
cartridge may be placed at the end of a hole formed in the coal, and the hole be
filled with water, the cartridge being exploded by means of a time fuse leading to
the vent hole of the plug, and ignited in the manner herein-before described.
An
When working in situations where there is no fear of accident from the presence
of carburetted hydrogen or other dangerous gases my improved method of getting
coal, blasting or disintegrating rock or other substances may be effected by the
employment of a solid metallic plug, having a priming or vent hole in its core, or a
groove along its side. The end of this plug which enters the blast hole is made
conical, and is fitted with a simple washer of lead to act as a check collar.
ordinary gunpowder or other explosive cartridge may be employed with this plug,
which cartridge is placed in a hole bored in the working, and charged with water
up to the cartridge, as in the before described arrangement, and the cartridge is
exploded by means of a time fuse, extending from the cartridge along the plug to
the vent hole. The plug is tightly fixed into the mouth of the blast hole without
compressing the cartridge, and is firmly shored up; the fuse is then ignited in the
usual way, or in the manner herein-before described with reference to the
chambered plug, when the coal or other substance will by the force of the explosion
be thrown down or disintegrated.
According to another method of carrying out my Invention I employ in com-
bination with my hydraulic exploding plug a non-inflammable explosive. In lieu
of charging the chamber of the breech piece with gunpowder 1 charge it with
highly compressed air, and provide at the orifice or bore of the cylinder next to the
explosive chamber a self-acting water-tight valve fitted to work on a sliding rod,
which passes through a cup leather and stuffing box in the breech piece of the plug.
This rod is actuated by means of a screw and lever in order to unship or release the
valve, when the trigger is acted upon or pulled suddenly so as to open the valvo
abruptly, and thereby cause the highly compressed elastic air to escape abruptly
from the breech chamber, and to act upon the water contained in the cylinder in a
similar manner to the gas from the gunpowder, as herein-before described, and so
throw down the coal or other substance, but without danger to the miners engaged
in the working.
When highly compressed carbonic acid gas is employed in the manner above
described, the water contained in the cylinder will absorb all the poisonous vapour
or noxious effects of the same, and such gas may be generated by combining a given
proportion of marble dust, chalk, or lime, and water with sulphuric acid, vinegar, or
hydrochloric acid, or other well known chemical combinations. These substances
or compounds are deposited in the breech chamber of the plug, which is then
tightly screwed into the cylinder, and when the desired pressure is generated the
valve herein-before described is opened by means of the trigger, when the gas
generated will press upon the water contained in the cylinder, and act in a similar
manner to the compressed air herein-before described, the water at the same time
absorbing the dangerous fumes or vapour of the carbonic acid gas generated.
To facilitate the charging of the plug with compressed air I employ an improved
air pump, which forces the air into the chamber of the breech piece by means of the

page_text: pressure of water or other suitable liquid contained in a double or U shaped
cylinder, worked upon the principle of the ordinary hydraulic force pump, of which
one of the inverted cylinders forms a part. This cylinder is fitted at the top with a
self-acting air regulating valve, which is caused to open and close by the ascent and
descent of the hydraulic piston or plunger.
The ordinary hydraulic valve is fitted at the bend between the two cylinders,
which valve is closed, and the water cut off by means of a tap or valvo in the water
inlet pipe when compressing the air. After the cylinders have been charged with
water the air valve is opened, when upon the ascent of the hydraulic piston air
will enter and fill the second cylinder, and on the descent of the piston such air
will be forced through and out of the discharge tube of the second cylinder into
the breech chamber of the plug, which is screwed on to the discharge tube to
receive it.
For the purpose of rapidly charging these plugs with compressed air I employ an
atmospheric accumulator, which is stored with compressed air in readiness for
immediate use when required. The compression of the air into the accumulator is
effected in a similar manner to that last described, the accumulator being attached
to the atmospheric tube in lieu of the breech chamber. The hydraulic air pump
and the accumulator are each fitted with an outlet tube provided with a valve or
tap for connecting them with the plug.
The hydraulic explosive plug herein-before described may be employed for
discharging shot or shells from cannons, discharging torpedoes, and may be
advantageously employed on board turret iron clad or other ships, and also in
casement batterys or forts, whereby the working of the guns may be effected
without encountering the poisonous fumes from the powder, whilst the guns will be
kept cool by the water employed.
.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Macnab in the Great Seal Patent Office on the 9th February
1877.
JAMES MACNAB, of Charlotte Street, Fitzroy Square, in the County of Middlesex.
"IMPROVEMENTS IN GETTING COAL AND OTHER MINERALS, BLASTING OR DISIN-
TEGRATING ROCK, AND IN THE APPARATUS TO BE EMPLOYED THEREIN, PARTS OF
WHICH APPARATUS ARE ALSO APPLICABLE FOR OTHER PURPOSES."
My said Invention relates to the employment of gunpowder or other inflammable
explosive material or gases for blasting or disentegrating coal and other minerals
and rocks without incurring danger from the flame, sinoke, or suffocating odour
from the explosive material employed either in underground workings or otherwise,
whilst, at the same time, a considerable saving of time is effected in the operation
of blasting; also to the employment of non-inflammable explosives in a similar
manner.
According to my Invention I employ, in combination with a simple boring
apparatus for boring the blasting holes a metallic plug constructed upon tho
principle of a breech loading cannon, and containing the explosive material, which
plug is inserted in the hole, and held securely therein during the time cf the
explosion by wedges or otherwise.
And in order that my said Invention may be fully understood I shall now proceed
more particularly to describe the same, and for that purpose shall refer to the
several Figures on the annexed two Sheets of Drawings; the same letters of
reference indicating corresponding parts in all the Figures.
Figure 1, Sheet 1, of the accompanying Drawings represents a side elevation of
the improved apparatus which I employ for boring the blasting holes; Figure 2 is a
vertical section of the same; and Figure 3 a detached view of a drill or tool for
boring holes of two different diameters.

page_text: Figure 4 is a longitudinal section of one modification of my improved metallic
plug for blasting or disintegrating rock, coal, and other minerals.
The remaining Figures represent details and modifications which will be herein-
after referred to.
My improved boring apparatus as illustrated by Figures 1 and 2 (Sheet 1)
consists of two hollow cylinders A, A³, provided respectively with right and left
hand internal screw threads fitting corresponding screw threads formed on a rod
or spindle B turned or rotated by means of a lover handle C the cylinders A, A¹,
being thereby caused to approach nearer to or recede further from each other,
according to the direction in which the spindle B is turned. By turning the
spindle in the requisite direction to cause the two cylinders to recede from each
other their outer ends will be forced respectively against the floor D and the roof E
of the working when operating on coal, for example, or against any other surfaces
suitably situate to receive their thrust. The outer ends of the cylinders are
provided with hinged pieces D',E³, for the purpose of admitting of their adjusting
themselves to any irregularities which may occur on the surface against which they
are caused to bear. Tho position of the drill upon the cylinders A, A, is adjusted
by means of a inetal collar F, which is fitted to slide along the same, and provided
with a screw G for the purpose of fixing it at any required elevation, according to
the position of the hole to be bored. This collar is also furnished with a stud H,
carrying a metal block I capable of being fixed by means of a nut a in any desired
angular position, and having a hole formed therein, through which is passed the
drill holder K. The drill holder carries a drill K, and is provided with a screw
thread working in a nut L, which is prevented from rotating with the holder K
when drilling a hole by a check nut or plate M screwed on to a stud N on the
metal block I, and caused to bear against one of the flat sides of the nut L. The
boring of a hole in the coal, for example, is effected by means of a ratchet brace O,
fitted on to the outer end of the drill holder K, and having a lever handle P for
the facility of operating the ratchet brace so as to impart a rotatory motion thereto,
the forward motion of the drill taking place at the same time by reason of the
thread of the drill holder working through the nut L.
In order to bore holes having two different diameters I fit into the holder Ka
compound drill or auger constructed as shown in Figure 3; the forward end 6 of
which is of less diameter than the rearward portion c, so that by the employment
of a drill of this construction a hole will be formed, the inner end of which to the
extent of the length of the portion b of the drill will be of less diameter than the
remaining portion; a shoulder being formed as shewn at d, Figure 3a, against
which the end of the blasting plug is caused to bear as herein-after described.
The drill or auger may be provided with an expanding and contracting leather
washer for discharging the debris from the hole as it is formed as described in the
Specification of Letters Patent granted to me, dated the Eighteenth September
One thousand eight hundred and seventy-five, No. 3281. In the hole thus bored I
fit the blasting plug next herein-after described.
According to one modification, which is illustrated by Figure 4, Sheet 1, the plug
consists of a hollow cylinder or tube Q, having fitted to its rear end a conical or 4
circular wedge-shaped breech R, provided with a chamber or recess S for the
reception of gunpowder or other explosive material. This chamber is separated
from the cylindrical bore T of the plug by a removable disc or stopper U of wood,
cork, or other suitable material inserted in or forced against the end of the boro
next the breach chamber S. The opposite or muzzle end of the cylinder is fitted 5
with a conical shield V, the external diameter of which is about equal to that of
the cylinder, whilst the internal diameter or bore W formed in the shield is less
than the bore of the cylinder. Upon this conical shield, and extending to about
half way up the same, I fit a lead or other soft metal collare for the purpose of
preventing the escape of the gases when the explosion occurs, which arrangement 5
is suitable when working hard minerals or rocks. When working coal, however, I
prefer to employ the arrangement described in my said former Specification, con-

page_text: sisting of a conical spring steel collar, which is caused to expand and slide up the
conical shield and jam itself into the coal by the force of the explosion acting upon
a metal disc or washer fitted behind the spring collar, and thereby make an air and
water tight joint around the external diameter of the muzzle end of the cylinder.
In the outer end f of the breech R there is formed a chamber g, in which I fit an
ordinary percussion gun lock h, and I. close the chamber by a screw plug i; this
chamber is in communication with the chamber S through a vent hole k in
connection with the nipple % of the gun lock h. The hammer m of the gun lock is
acted upon from a distance so as to discharge the explosive material by means of
a cord or wire connected to a spring clip o (see Figure 4) engaging with a rod p
attached to the hammer m, which spring clip, when the hammer is raised to its full
extent, is acted upon by a stationary pin q so as to cause it to open out at o' and
become disengaged from the rod p, upon which the hammer will, by the action of the
main spring r, be caused to strike a percussion cap placed upon the nipple 2, and
thereby effect the discharge of the powder contained in the chamber S.
By enclosing the gun lock or firing mechanisin in a chamber as above described
the percussion cap is exploded without being permitted to have any communication
with the gaseous or external atmosphere of the mine or underground working.
For the purpose of maintaining the plug in position during the explosion I form
a groove t round the breech R for the reception of a metal ring or clip u, to which
are hinged two lever arms or bars v, v, so arranged as to be capable of being adjusted
to any desired angle, and when adjusted of holding the plug securely in the blasting
hole by wedging against a shoreing block w or against the opposito face or other
suitable part of the working.
In operating with this apparatus, the hole having been bored in the required
position in the coal, I unscrew the breech R from the cylinder Q of the blasting
plug, and place in the chamber S cither loose powder, a cartridge, or other suitable
explosive charge; I then introduce the plug U into the bore of the cylinder, and fill
the latter with water or other suitable liquid by means of a syphon or otherwise,
and insert a cork or other suitable plug into the muzzle end of the cylinder in
order to prevent the escape of the liquid. The breech R containing the explosive
charge is then screwed on to the cylinder Q, and the cylinder inserted into the hole
prepared for its reception, the muzzle end of the cylinder being caused to bear
against the shoulder & (Figure 3a) formed by the drill, and which, when the explo-
sion takes place, causes the lead collar e or the spring collar, herein-before described
(as the case may be), to jam itself into the coal, and thereby prevent the escape of
any of the gas past the blasting plug. The blasting plug thus inserted in the hole
is shored up by the means herein-before described in order to prevent it from
starting out of position by the force of the explosion. The plug i of the chamber
containing the lock is now removed and the nipple capped, after which the plug i
is replaced; the rod p is then passed through an opening in the plug i, and screwed
into a piece z hinged to the hammer m; the outer end of the rod p is then con-
nected to the spring clip o, and the cord or wire n being also attached to the latter,
all is ready for action.
The firing party having retired from the face of the coal out of danger, the cord
or wire n is pulled out until the spring clip o draws the hammer back to its full
extent; the rod p will then become disengaged from the spring clip o by the
vertical pin 9 acting upon the arms of the latter so as to open them out, when the
hammer will be also released, and effect the explosion of the charge contained in
the breech chamber S.
The elastic gas generated by the explosion suddenly expands and presses upon
the water contained in the bore T of the cylinder, discharging it into the coal,
which it will throw out with more or less force, according to the power of the charge
contained in the breech. The lead collar e or its equivalent spring collar at the
muzzle of the plug will at the same time be caused by the force of the explosion to
slide up the shield V, and wedge itself into or between the coal and the muzzle end
of the cylinder, and thereby prevent the escape of the gas past the blasting plug.

page_text: The incandescent vapour or the flame of the ignited gunpowder or other explosive
material is extinguished before it has time to escape from the contracted muzzle end
of the blasting plug, and the suffocating smoke and poisonous gas (carbonic acid
gas) are simultaneously absorbed by the water contained in the cylinder; thus the
air of the coal mine is not affected or rendered impure, and all inflammable and
other dangerous influences are completely neutralized.
In lieu of employing loose gunpowder, as herein-before described, a water-tight
cartridge may be placed in the chamber of the breech, and be connected to the vent
hole of the gun lock by a tube containing powder or by means of a fuse, the
cartridge itself being surrounded by the water contained in the plug..
Figure 5, Sheet 1, is a longitudinal section, and Figure 6 a transverse section of
another modified construction of blasting plug, in which the charge contained in the
breech R is exploded by means of a striking pin in lieu of a hammer, as herein-
before described with reference to l'igure 4, Sheet 1.
According to this modification the breech R is formed in one with the cylinder Q,
and is fitted with a closing wedge-shaped breech block 18, arranged to slide vertically
in an opening formed transversely in the breech, and which may be held securely in
its closed position by a nut 20 screwed on to its smaller end. The cartridge is
introduced into the breech chamber $ through an opening formed in the end of the
breech, which opening is closed after the charge has been inserted by a metal
block retained in its closed position by a bolt or pin 21 fitted to slide in a strap or
guido 22 secured to the end of the breach. The block i carries the striking pin 19,
which in the present example is constructed in two parts, and is acted upon in order
to explode the cartridge by a helical spring 23, bearing at one end against a screwed
plug 24 fitted into the end of the block i, and at its opposite end against a collar 25
fitted on to the striking pin 19. The breech is enclosed in a inetal cap 26 provided
with a removable end 27 to facilitate access to the striking pin for the purpose of
cocking the apparatus.
"
When it is required to charge the plug the cap 26 is first unscrewed from the
breech, and the block i containing the striking pin 19 removed; the breech block 18
is then raised, thereby leaving a free passage for the cartridge into the chamber S;
the cartridge is then introduced, and the breech block 18 is replaced and secured in
position by the nut 20; the block i containing the striking pin 19 is then inserted
in the end of the breech and locked in position by the bolt 21, and the whole is then
enclosed by the cap 26.
In order to cock the apparatus in readiness for exploding the charge I remove the
end 27 of the cap 26, and draw back the striking pin 19 so as to compress the
spring 23, and I retain it in this position by a bolt 28, which passes through a
stuffing box 29 in the cap 26, and enters a hole 30 provided for the purpose in the
striking pin 19.
When it is desired to explode the charge the bolt 28 is withdrawn from the
striking pin 19 by means of a cord, wire, or chain line connected to the outer end
thereof; the striking pin will then, under the action of the spring 23, be impelled
suddenly forward, and effect the explosion of the cartridge.
In some cases I drill the blast hole in a descending angular direction, and charge
it with water; the explosive force of the powder is then caused to act direct upon
the interior of the chamber formed in the coal itself, the cartridge being placed at
the end of the hole formed in the coal, substantially as shewn in Figure 7, Sheet 1,
and herein-after described, and the charge exploded either by means of a time fuse
passed through the plug, and ignited in the manner herein-before described by
means of a gun lock and hammer, or otherwise.
When working in situations where there is no fear of accident from the presenco
of carburetted hydrogen or other dangerous gases, the modification shewn in
Figure 7, Sheet 1, may be adopted. According to this arrangement I employ a
solid metal plug Q having a priming or vent hole in substitution for the hollow
plug containing water herein-before described. The back end of this solid
plug which enters the blast hole is made conical, and formed with annular notches 1

page_text: for the purpose of effecting a tight joint at that part, a simple washer of lead being
also provided if required to act as a check collar; with this plug I employ an
ordinary gunpowder or other explosive cartridge S, which is placed in the hole
bored in the working. The hole is charged with water up to the cartridge, as in
the before-described arrangement, and the cartridge is exploded by means of either
a time fuse or a striker l, as shewn, extending from the cartridge through the plug to
the exterior of the rear end thereof. The plug is tightly fixed into the mouth of
the blast hole without compressing the cartridge, and is firmly shored up; the fuse
is then ignited or the striker acted upon in the usual way, or in the manner herein-
before described with reference to the chambered plug, so as to explode the charge
when the coal will, by the force of the explosion, be thrown down or dis-
integrated.
Figure 8, Sheet 2, is a longitudinal section illustrating another modification of
the blasting plug with which employ a non-inflammable explosive. In lieu of
charging the chamber S of the breech R with gunpowder I introduce highly com-
pressed air in the manner herein-after described, and provide at the orifice or bore
of the cylinder next to the chamber S a self-acting water-tight valve 2 fitted to
work on a sliding rod 3, which passes through a cup leather 4 in the breech R of
the plug. This rod has formed thereon a screw thread 5, and is actuated by means
of a nut G and lever 7, which latter is pulled suddenly, so as to open the valve
abruptly, and thereby cause the highly compressed air to escape with violence from
the breech chamber S, and to act upon the water contained in the cylinder Q in a
similar manner to the gas from the gunpowder, as heroin-before described, and
so throw down the coal, but without danger to the miners engaged in the
working.
For the purpose of charging the blasting plug with compressed air any suitable
air pump or air-forcing apparatus may be employed, such, for example, as that
described in my said former Specification.
When highly compressed carbonic acid gas is employed in the manner above
described the water contained in the cylinder Q will absorb all the poisonous or
noxious vapour of the same. The gas may be generated by placing in the chamber
S marble dust, chalk, or lime, and water in suitable proportions with sulphuric acid
and vinegar, or hydrochloric acid, or other well-known chemical combinations. These
substances or compounds having been deposited in the breech chamber S the plug i
is tightly screwed into the breech, and when the desired pressure is generated the
valve 2 is opened by means of the lever 7, when the gas generated will press upon
the water contained in the cylinder Q, and act in a similar manner to that herein-
before described with reference to compressed air, the water at the same time
absorbing the dangerous fuines or vapours of the carbonic acid gas generated.
For undercutting or holeing I proceed in the following manner, reference being
had to Figure 9 (Sheet 2) of my Drawings:-I first drill or bore an ordinary blast
hole 12 of the diameter of the cylinder of the blasting plug in a horizontal or
nearly horizontal direction in the broken end foot or side of the coal face or wall at
a few inches from the bottoin of the working, and to a depth of, say, about three or
more feet froin the face. Into the hole thus prepared I force the plug (by means of
the boring tool holder or otherwise) until its circular wedge-shaped breech R enters
the mouth of the hole, so as to fill up any irregularities at that part. The plug is
then shored up, so as to prevent it from starting out of position at the time of the
discharge, and the explosion is effected in the manner herein-before described. If
the block or mass of coal has not been loosened or thrown down by the explosion
the operation is followed by boring another similar blast hole 13 parallel to and
immediately above the previous one, but at the top of the coal seam, in which hole
a charge is exploded, which will cause the block or mass of coal to break away, or
be thrown down by the powerful leverage exerted upon it by the second explosion.
Or in lieu of boring a second hole parallel to the first the usual well-known method
of drilling one or more holes at the top of the coal face may be adopted, and the

page_text: coal be operated upon with my blasting plug in the manner herein-before described;
or any desired number of blast holes may be made successively in a receding
direction from the face of the coal until the requisite depth is attained, and
an explosion effected in the manner herein-before described in each hole in suc-
cession, so as to undercut a large block or mass of coal.
According to another method I drill blast holes near the bottom of the face of
the coal seam at an acute ascending angle, or I drill two blast holes converging to
a point in the interior of the seam, and effect an explosion therein in the manner
Jerein-before described, which will cause the coal to be thrown down without under-
cutting or holeing; or I undercut at an anglo at the heading by boring a blast
hole at the bottom of one of the extreme sides of the face of the working, and
throw down by exploding a charge therein. I then work from the other extreme
side of the face, and throw down in a similar manner, thus breaking into the seam
head.
When fissures or rents exist in the coal to be operated upon, and also when blast
holes are bored at an ascending angle, I insert in the hole in combination with the
blasting plug a metal tube containing water in lieu of introducing water into the
hole direct. This arrangement is illustrated in Figures 10 and 11, Sheet 2.
S, Figure 10, is the tube which constitutes a water cartridge, and is closed at one
end and filled with water, the open end being screwed on to the end of the
cylinder of the blasting plug, and an explosion effected in the breech of the plug,
as herein-before described, which causes the rupture of the cartridge S³, and thereby
effects the disintegration of the coal being operated upon. Or the open end of the
cartridge S¹ is closed by a plug of cork or other suitable material a, Figure 11, and
the closed end connected to the muzzle end of the cylinder Q of the blasting plug,
a gunpowder cartridge S being placed inside the water cartridge S¹ which may be
exploded in a similar manner to that described with reference to the cartridge
employed in the arrangement, Figure 7, Sheet 1, the force of the explosion causing
the cartridge S¹ to expand and prevent the escape of the water from the blast
hole..
A cartridge constructed in a similar manner, so as to be capable of expanding,
may also be employed when the holes are bored in a horizontal or descending
direction and the water is contained in the hole, in which case the use of water in
the interior of the cartridge may be dispensed with, whilst at the same time
utilizing the expansive action of the cartridge to maintain a tight joint between
the end of the cylinder of the blasting plug and the sides of the holo at the time of
the explosion of the charge.
The blasting plug herein-before described may be employed for discharging shot or
shells from cannons, discharging torpedoes, and may be advantageously employed on
board turret ironclads or other ships, and also in casement batteries or forts, whereby
the working of the guns may be effected without encountering the poisonous fumes
from the powder, whilst the guns will be maintained in a cool condition by the
water employed.
Figure 12, Sheet 2, is a longitudinal section of a breech-loading cannon illustrating
the application thereto of my system of neutralizing the effects of the flame and
smoke from the gases generated by the explosion of gunpowder.
According to this arrangement the projectile is separate from the powder cartridge
and placed in the breech end of the bore of the gun, as shewn at 14, and the breech
chamber S is partly filled with water, an india-rubber washer or ring being placed
round the end of the projectile to prevent the escape of the water into the bore of
the cannon.
A gunpowder cartridge 15 having its forward end plugged, so as to
exclude water, is next inserted into the chamber S and retained in position by a
sliding breech block 16 in the ordinary manner, a washer of india-rubber being
provided at the end of the cartridge to provent the water contained in the chamber
from escaping at that part. This cartridge is exploded in the ordinary manner by
a striking pin 17 acting upon a detonating cap fitted in the end of the cartridge,

page_text: the explosion causing the projectile to be ejected from the cannon with great force,
whilst the water contained in the chamber between the cartridge and the projectile
will entirely condense or neutralize the flame and smoke arising from the explosion
of the cartridge.
In carrying on mining operations should a fire occur my blasting plug may
be utilized for extinguishing the same. It thus affords a means always available for
promptly arresting a fire at its outbreak, and which may be used either as a
substitute for or as an auxiliary to the methods ordinarily employed for the purpose.
Although I prefer to explode the charge contained in the various modifications of
apparatus by means of the detonating arrangements herein-before described I do
not wish to limit myself thereto, as it is obvious that the explosion may be effected
by electricity or otherwise. When electricity is employed the ordinary tamping may
be used in substitution for the blasting plug if desired.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that I do not confine myself to the precise
details herein-before described and illustrated on the accompanying Drawings,
except as herein-after specified, as they may be modified without departing from
the principle of my Invention, but what I consider to be novel and original,
and therefore claim as the Invention secured to me by the herein-before in part
recited Letters Patent is,-
First. The application and use to and in the mining, blasting, or disintegrating of
coal, minerals, and rocks, of water or other liquid in combination with gunpowder
or other inflaminable explosive agent or non-inflammable equivalent therefor sub-
stantially in the manner herein-before described.
Second. The employment in combination with water or other liquid in conjunction
with gunpowder or other inflammable explosive agent, or non-inflammable equivalent
therefor, of a charge containing plug or apparatus constructed and operated sub-
stantially in the manner and for the purposes herein-before described.
Thirdly. The peculiar constructions and arrangements of charge containing plugs
or apparatus, substantially as herein-before described and illustrated by Figures 4,
4, 7, and 8 of my Drawings.
Fourthly. The general arrangement and combination of apparatus for drilling or
boring holes in coal, minerals, and rocks, and for forcing the blasting plug into the
holes thus formed, substantially as herein-before described and illustrated by my
Drawings.
Fifthly. The system or mode of discharging projectiles from ordnance and other
fire-arms by causing the gases from the explosion of the charge to act upon the
projectile through the medium of an intervening layer of water or other liquid,
substantially as and for the purposes herein-before described.
In witness whereof, I, the said James Macnab, have to this my Specification
set my hand and seal, the Seventh day of February, One thousand eight
hundred and seventy-seven.
JAMES MACNAB. (L.S.)