Year: 1887

page_text: This Specification has been amended, see Star number.

page_text: This Specification was, upon the 6th day of December 1887, amended under
Sections 18 to 21 of the Patents, Designs, and Trade Marks Act, 1883.
Improved Method of and Apparatus for Testing Gases Drawn from
Mines and Signalling or Indicating the Result thereof, and for
General Signalling in Mines.
I, THOMAS SHAW of the City and County of Philadelphia, and State of Pennsylvania
United States of America, Mechanical Engineer do hereby declare the nature of this
invention to be as follows:-
This invention consists in the device for automatically testing mine gases combined
with an ordinary tube for conducting the gases to said device which tube is combined
and operated by alternating partial vacuum and high pressure air or gas currents
to produce signals all operating in the manner and for the purpose hereinafter
described.
The object of the invention is to give positive automatic tests of explosive gases
from mines and to give and to receive signals from all parts of the mines desired as
hereinafter explained.
When explosive gases or gases which on combining with air form explosive gases
first enter a mine or a chamber therein they rise to the upper part of the chamber
and gradually fill the latter from the top and through diffusion will mix with the
upper strata of air in explosive proportions working from the top downward so that
the lower strata of air in which the men work will only indicate danger after the
chamber is so full of gas that it is difficult to avoid the consequences of its
presence.
Attempts are made by Inspectors to test the gases by elevating safety or indicating
lamps to the tops of the mine chambers by poles and otherwise but they are then so
far removed from the Inspector that it is impossible for him to correctly ascertain the
indications except when the lamp is extinguished by the explosive gases, creating an
explosive effect within the lamp which is regarded as highly dangerous to the
Inspector and occupants of the mines. The test by lamps is at best of an extremely
negative character under favourable circumstances, whilst under unfavourable circum-
stances such as daily occur iu mines, the test is made at peril of life and is very
unreliable.

page_text: Any means of remedying these difficulties and affording a sure and immediate
positive indication of the presence of explosive gases must be of such a character as to
be practically employed by unskilled labor and not liable to get out of order or to
become useless from the necessary rough usage to which the same is subjected in
mines.
The means devised to meet the requirements specified consist of a pipe leading from
a high point in the chamber of the mine to the surface.
The pipe is put in communication with an exhaust pump and a small pipe from the
latter leads to a metallic gun or cylinder having a contracted opening at one side
opposite a flame or incandescent igniter and at one end a loose piston valve opposite a
gong with a spring for retracting the piston valve.
If the pump is put in operation the air will be exhausted from the pipe leading to
the chamber by the pump and will be drawn from the top of the chamber and forced
through the gun.
So long as air alone is thus conducted no other effect results but should a gas
which is explosive or an explosive mixture of air and gas be drawn into the tube and
forced into the gun it will upon meeting the flame be ignited and the charge within
the gun will explode driving the piston valve outward against the gong and sound the
latter in a loud and positive manner. The presence of dangerous gas is thus auto-
matically indicated in a few moments after it begins to enter any chamber and long
before it can accumulate in dangerous quantities and be brought in contact with lights
at lower levels, where men are working etcetera.
A separate pipe leads from each working chamber of the mine to a separate gun or
indicator at the surface.
As will hereinafter be explained each gun is provided with means as a self closing
valve or contracted passage way to prevent the gas and flame from travelling back to
the mine chamber and it will be understood that the parts may be variously con-
structed to automatically propel and conduct the gases and afford an automatic
indication of their presence. For instance the pump may be constructed in different
ways. The gas may be ignited by an incandescent body a flame or an electric spark,
the indicator instead of being a gong may be a piece of travelling paper which is
punched by the piston or the gases may be blown against a chemically prepared
surface which becomes coloured only on the presence of dangerous gas. In either
case however it will be seen that there is a constant automatic withdrawal of gas or
air from an elevated point in each working chamber of the mine and the character of
the gas thus withdrawn is indicated at the surface in a manner to convey immediate
information to the attendants at a central point. While the apparatus having the
general features specified will effect the indications at the surface of the character of
gas in the mine it has the further advantage of also affording means of signalling
from the central station and back to the chamber. Thus by obstructing the flow of
air to the pump or by reversing the current by air pressure from another pump or a
reservoir through the pipe leading into the chamber the current may be forced back
through the said pipe and out of the inner end through a whistle or other alarm
device at said end and by closing the inner end of the pipe by compressing an elastic
portion say a rubber tube by the fingers a partial vacuum is formed in said pipe and
is made the means of sounding a whistle or alarm at the central station. Having
stated the general features of this invention I will now set forth in detail the con-
struction of the various parts as I have used them it being understood however that
such constructions may be greatly varied without departing from the essential features
of this invention.
The pipes leading from the different chambers are conducted to an engine house or
central office within which is arranged the indicating and signalling apparatus con-
sisting of a framework supporting two tables placed one above the other the upper of
which carries the "tester "apparatus.
The gun is a hollow cylinder and the piston thereof constitutes also a valve closing
the rear end of the cylinder and held in its closed position by bow springs which press
the piston valve inward the explosion driving it outward against a gong. At the

page_text: middle portion of the cylinder is a valve box containing a valve hinged on its lower
edge to fall inward against a stop arm limiting the width of the opening and closing
outward on each explosion in the gun or cylinder. The purpose of the valve is to
cause the explosive effect to exert all its force on the piston valve. Beyond the port
of the valve is a short tube or nozzle which leads the gas from the valve port to the
flame of a lamp the said nozzle is contracted to about one third its diameter at the
outer end to cause wave puffs of explosive gases that are favorable for ignition of
gases of low explosive effect.
There is a port in the top of the valve box of the cylinder and a hinged arm falls
over the same so as to be swung back when an explosion occurs thereby indicating to
the attendant the signalling device which has been operated by the explosion of
dangerous gases.
Such indicator is generally advisable as two signals may be simultaneously operated
in a gang of a dozen or more and without such indication the attendant would be at a
loss to determine the chamber in which the gases are present.
The gases are driven into the gun through a small pipe communicating with a
rotary pump or blower and when an explosive gas or mixture of gas and air is thus
introduced it flows out of the igniter port and is ignited the force of the explosion
closing the valve and forcing out the piston valve against the gong and throwing
back the indicator and this will be repeated at short intervals so long as repeated
charges of explosive gas are introduced into the gun. The entire amount of gas
drawn from the chamber by the pump is not thrown into the gun but the pump is
provided with an overflow pipe through which the surplus gas escapes the amount of
escape being controlled by a valve.
In order to permit of the end of pipe leading from the chamber being readily
carried to the top of the mine chamber and there secured such end is provided with a
flexible terminal pipe and at the end of this flexible section is secured a nozzle
provided with an eye by means of which to suspend it in an elevated position or to
secure a cord for raising and lowering it and at the end of the nozzle is placed an
ordinary whistle. A valve casing containing a valve opening inward and covered by
wire cloth to keep out dirt communicates with the nozzles so as to admit the air or
When a
gases through the nozzle to the conducting pipe when the pump is started.
reverse current is sent through the pump from the central station the whistle is
sounded and by intermitting the current distinct sounds may be made in accordance
with any desired prearranged system as hereinafter set forth so as to afford a means
of sending messages of any character back into the mines.
The reverse current may be forced back by the pump but a reservoir containing air
under pressure and a valve device is preferable whereby to cut off the flow to the
pump through the pipe and at the same time put the reservoir into communication
with the pipe to send a reverse current in the pipe leading to the chamber above
mentioned.
The valve device is in the line of the chamber pipe and consists of valve casing
arranged to cover a common D valve and two ports in the tube passage between the
two tube sections. The casing of the valve device is connected by a pipe with the
reservoir. The valve is actuated by moving a hand lever and when the lever is
depressed it rotates a shaft and an inner arm on the said shaft and connected with the
valve shifts the same. A weight or spring connected with a wire rod brings the valvo
back to the normal position. When the valve is in the proper position for testing the
gas the air current Hows uninterruptedly from the mine chamber to the pump. When
it is desired to reverse the current in the tube for the purpose of signalling back to
the mines the valve is placed in the proper position which closes the port to the pump
and opens the other port so that air can pass to the whistle in the mine and their
sound the signal alarm after which the valve when the hand is removed immediately
recovers its normal position and the air passes to the pump and gun.
Thus as soon as the attendant at the central station is automatically notified by the
signal device that there is dangerous gas in a chamber he can send a down current

page_text: through the chamber pipe and at once notify the miners of their danger, or send
desired instructions.
The apparatus is also provided with a means of signalling from the mine to the
station above the ground. The variation of pressure in the pipe is made the means of
admitting air to a whistle at the station and the compressing of the flexible
tube of the chamber pipe will serve to prevent the flow of air or gas from the
mine and thus cause an exhaust or partial vacuum vary the pressure and make the
signal.
The device actuated by the varying pressure to cause the signal may consist of a
metallic casing secured beneath the table by pillar supports; the chamber portion
contains a diaphragm of sheet rubber secured between two discs the outer edge of the
diaphragm is clamped at the edge between the two parts of the casing. In the centre
of said diaphragm is secured a valve stem which passes through an ordinary
packing to the valve casing and there carries a common slide valve covering a port
which leads to the pipe of the whistle. The diaphragm is connected by a link to a
pivoted weighted lever. A. tube leads to the casing from the air pressure cylinder so
that high pressure air is always present in valve chamber. A tube is connected with
the tube from the mines so that when the rotary pump is working there is a constant
partial vacuum on the under side of the diaphragm tending to draw it downward
which is counteracted by an excess of weight on the lever which forms a balance with
excess on the weight side so that when the elastic tube is closed by pressure of the
fingers a vacuum of greater intensity is produced drawing said diaphragm downward
uncovering the port and permitting air to pass from the reservoir and pipe and thus
sound the whistle which sound ceases after the compression of the tube ceases.
signals are sent from the mines to the station above actuated by power at the upper
end and by alternately compressing and releasing the elastic pipe a series of signals
may be made according to any predetermined system which will enable the miners to
send any desired information to the central station.
Thus
To prevent any confusion of signals each whistle is provided with a hinged indicator
which is thrown backward by the current of air and indicates that the whistle has been
sounded.
The construction of signalling and indicating and blowing apparatus is not limited
as any skilled mechanic will be able to supply differently constructed devices which
will effect the desired results.
As before stated it is intended that each part of the mine required to be tested shall
be provided with a separate tube and automatic gas testing and indicating contrivance
of the character fore described, all under the control of one operator at the testing
station so that all parts of the mine are under constant supervision, and constant
accurate and infallible tests of the air or gases in each part of the mine are made and
the miners are in constant communication by the combined system of signalling
causing the central station to work not unlike a telephone exchange in ready com-
munication with all working parts of the mines enabling the superintendent to have
reports at short intervals of gas tests and to give orders and to receive answers and to
know the working of each section of the mines without the usual unavoidable and
often fatal delays attending the use of testing means and the special messenger system
heretofore employed.
AL
W. P. THOMPSON & BOULT,
Agents.

page_text: far removed from the inspector that it is impossible for him to correctly ascertain the
indications except when the lamp is extinguished by the explosive gases creating an
explosive effect within the lamp which is regarded as highly dangerous to the
inspector and occupants of the mine. The test by lamps is at best of an extremely
negative character under favorable circumstances whilst under unfavorable circumstances
such as daily occur in mines the test is made at the peril of life and is very unreliable.
Any means of remedying these difficulties and affording a sure and immediate
positive indication of the presence of explosive gases must be of such a character as to
he practically employed by unskilled labor and not liable to get out of order, or to
become useless from the necessary rough usage to which the same is subjected in
mines.
The means I have devised meet the requirements I have specified and can best be
understood in their general features by reference to the diagram Fig. 15.
In said diagram a represents one of the chambers of the mine; 11, the vertical
shaft; a communicating level or gallery and a pipe leading from a high point in
the chamber a¹ to the surface.
The pipe is put in communication with an exhaust pump g" and a small pipe b¹
from the latter leads to a metallic gun or cylinder p having a contracted opening at
one side opposite a flame or incandescent igniter w and at one end a loose piston
valve S opposite a gong with a spring t for retracting the piston valve.
If the pump is now put in operation the air will be exhausted from the pipe by
the pump and will be drawn from the top of the chamber a¹¹ and forced through the
gun p.
So long as air alone is thus conducted no other effect results, but should a gas
which is explosive or an explosive mixture of air and gas be drawn into the tube b
and forced into the gun it will upon meeting the flame w be ignited and the charge
within the gun will explode driving the piston valve outward against the gong and
sound the latter in a loud and positive manner. The presence of dangerous gas is
thus automatically indicated in a few moments after it begins to enter any chamber
and long before it can accumulate in dangerous quantities and be brought in contact
with lights at lower levels where men are working etc.
A separate pipe leads from each working chamber of the mine to a separate gun or
indicator at the surface.
As will hereinafter be explained each gun is provided with means such as a self
closing valve or contracted passage way to prevent the gas and flame from travelling
back to the mine chamber, and it will be understood that the parts indicated in said
diagram may be variously constructed to automatically propel and conduct the gases
and afford an automatic indication of their presence. For instance the pump may be
constructed in different ways, the gas may be ignited by an incandescent body a flame
or an electric spark the indicator instead of being a gong may be a piece of
travelling paper which is punched by the piston or the gases may be blown against a
chemically prepared surface which becomes colored only on the presence of
dangerous gas.
In either case however it will be seen that there is a constant
automatic withdrawal of gas or air from an elevated point in cach working chamber
of the mine and tho character of the gas thus withdrawn is indicated at the surface in
a manner to convey immediate information to the attendants at a central point.
While the apparatus having the general features specified will effect the indications at
the surface of the character of gas in the mine it has the further advantage of also
affording means of signalling from the central station and back to the chamber. Thus
by obstructing the flow of air to the pump g or by reversing the current by air
pressure from another pump or a reservoir through the pipe b, the current may be
forced back through the pipe b and out of the inner end through a whistle or other
alarm device at said end and by closing the inner end of pipe b by compressing an
élastic portion say a rubber tube, by the fingers, a partial vacuum is formed in said
pipe and is made the means of sounding a whistle or alarm at the central station.
Having stated the general features of my invention I will now set forth in detail the
construction of the various parts as I have used them, it being understood however

page_text: that such constructions may be greatly varied without departing from the essential
features of my invention.
In fig. 11 the central station is shown as arranged in an engine house or central
office to which all the pipes p" lead from the different chambers of the mine.
Within this house is arranged the indicating and signalling apparatus more fully
illustrated in figs. 6, 7, 9, 10, 12, 13 and 14 and in figs. 1 to 5. Said apparatus is
supported by a frame work having two platforms or tables c¹ and h¹¹.
On the tables c¹ figs. 10 and 13 is supported the tester the construction of which
is more fully illustrated in figure 6.
The gun is a hollow cylinder and the piston S constitutes also a valve closing the
rear end of the cylinder and held in its closed position by the bow springs t, t which
press the piston valve S inward the explosion driving it outward against the gong v.
At the middle portion of the cylinder is a valve box shown in section in fig. 7 con-
taining a hinged valve y hinged on its lower edge to fall inward against the stop arm
shown in fig. 7 limiting the width of the opening and closing outward on each
explosion in the gun or cylinder. The purpose of the valve is to cause the explosive
effect to exert all its force on the piston valve S. Beyond the port of the valve y is a
short tube or nozzle Z which leads the gas from the valve port to the flame of a lainp w
the said nozzle Z is contracted to about one third its diameter at the outer end to
cause wave puffs of explosive gases that are favorable for ignition of gases of low
explosive effect.
There is a port in the top of the valve box of the cylinder, and a hinged arm a
falls over the same so as to be swung back to the position shown in dotted lines fig. 6,
when an explosion occurs thereby indicating to the attendant the signalling device
which has been operated by the explosion of dangerous gases.
Such indicator is generally advisable as two signals may be simultaneously operated
in a gang of a dozen or more and without such indication the attendant would be at a
loss to determine the chamber in which the gases are present.
"
The gases are driven into the gun p through the small pipe b¹ figs. 7, 10, and 14,
communicating with the rotary pump or blower and when an explosive gas or
mixture of gas and air is thus introduced it flows out of the igniter port and is ignited
the force of the explosion closing the valvey and forcing out the piston valve S against
the gong and throwing back the indicator a¹ and this will be repeated at short
intervals so long as repeated charges of explosive gas are introduced into the gun.
The entire amount of gas drawn from the chamber by the pump is not thrown into
the gun but I provide the pump with an overflow pipe through which the surplus
gas escapes, a valve at el, fig. 10, controlling the amount of escape.
In order to permit the end of pipe b, fig. 15, to be readily carried to the top of the
mine chamber and there secured I provide such end with a flexible terminal pipe f
(fig. 8) and at the end of this flexible section I secure a nozzle e¹, provided with an
eye e by means of which to suspend it in an elevated position or to secure a cord for
raising and lowering it, and at the end of the nozzle I place an ordinary whistle d'.
A valve casing containing a valve opening inward and covered by wire cloth g' to
keep out dirt communicatos with the nozzles so as to admit the air or gases through
the nozzle to the conducting pipe when the pump is started. When a reverse current
is sent through the pump from the central station the whistle is sounded and by inter-
mitting the current distinct sounds may be made in accordance with any desired
prearranged system as hereinafter set forth so as to afford a means of sending messages
of any character back into the mines.
The reverse current may be forced back by the pump but I prefer to use a
reservoir containing air under pressure and a valve devico (figs. 1, 2, 3, 4, 5, 10, 13
and 14) whereby to cut off the flow to the pump through the pipe c and at the
same time put the reservoir "into communication with the pipe to send a reverso
current in pipe b.
In the construction shown the valve device (figs. 13 and 14) is in the line of pipe b
and consists of valve casing a (figs. 1 to 5) arranged to cover a common D-valve n
and two ports k and I in the tube passage between the two tube sections b, c. The

page_text: The
casing of the valve device is connected by a pipe d with the reservoir f".
valve n is actuated by moving a hand lever e, when the lever is depressed to the posi-
tion shown in dotted lines fig. 1, it rotates the shaft and an inner arın m on the
shaft and connected with the valve shifts the same from over the port k to the position
shown in figure 5. A weight or spring connected with a wire rod g brings the valve
back to the normal position shown in figure 4.
The pipe b connects with the mine chamber and the pipe e to the pump and
the piped to the reservoir fil containing air under pressure. When the valve
is in the position fig. 4, which is the proper position for testing the gas the air
current flows uninterruptedly from the mine chamber through the pipe b port k
valve n and port and pipe c to the pump. When it is desired to reverse the current
in the tube b for the purpose of signalling back to the mines the valve is placed
in the position fig. 5, which closes the port to the pump and opens the port k so
that air can pass through the pipe d, casing a and through the pipe to the
whistle d' in the mine and there sound the signal aların after which the valve when
the hand is removed immediately recovers its normal position, fig. 4, and the air
passes to the pump and
gun.
Thus as soon as the attendant at the central station is automatically notified by the
signal device that there is dangerous gas in a chamber he can by depressing the valve
lever send a down current through the pipe band at once notify the miners of
their danger or send desired instructions.
e,
The apparatus is also provided with a means of signalling from the mine to the
station above the ground. The variation of pressure in the pipe bis made the means
of admitting air to a whistle a¹¹ (figs. 10, 12, 13 14) at the station and the compressing
of the flexible tube, fig. 8, of the pipe b will serve to prevent the flow of air or gas
from the mine and thus cause an exhaust or partial vacuum, vary the pressure and
make the signal.
A device actuated by the varying pressure to cause the signal is shown in figure 9.
A metallic casing is secured beneath the table e¹ by pillar supports; the chamber
portion u contains a diaphragm of sheet rubber secured between two discs S¹ the
outer edge of the diaphragm is clamped at the edge between the two parts of the
casing. In the centre of said diaphragm is securod a valve stem which passes through
an ordinary packing t to the valve casing o¹ and there carries a common slide valve
covering a port which leads to the pipe of the whistle a¹¹, figs. 10 and 12. The
diaphragm is connected by a link to a pivotted weighted lever . A tube n' leads
to the casing o' from the air pressure cylinder f", fig. 14, so that high pressure
air is always present in valve chamber. A tube m' is connected with the tube b
from the mines so that when the rotary pump g is working there is a constant partial
vacuum on the under side of the diaphragm S₁ tending to draw it downward which
is counteracted by an excess of weight on the lever which forms a balance with
excess on the weight side so that when the elastic tube f¹ figs. 1 and 8, is closed
by pressure of the fingers a vacuum of greater intensity is produced drawing said
diaphragm downwards uncovering the port ¹ and permitting air to pass from the
reservoir and pipe n¹ to the port and thus sound the whistle a" which sound ceases
after the compression of the tube f¹ ceases. Thus signals are sent from the mine
to the station above actuated by power at the upper end and by alternately compressing
and releasing the elastic pipe, a series of signals may be made according to any
predetermined system which will enable the miners to send any desired information
to the central station.
a
To prevent any confusion of signals each whistle a fig. 12, is provided with 5
hinged indicator n" which is thrown backward by the current of air and falls in the
position shown in dotted lines which indicates that the whistle has been sounded.
I do not limit myself to the precise construction of signalling and indicating
and blowing apparatus shown as any skilled mechanic will be able to supply
differently constructed devices which will effect the same results as those set forth
which have proved most effective in actual operation.
in the apparatus shown the revolving shaft of the pump is driven by a belt u¹¹

page_text: passing around pulleys as shown in figs. 10 and 14 from a shaft r" to which motion
is imparted from an adjacent driving shaft but this arrangement will be varied when
a differently constructed pump is used. Any ordinary air pump can be used to fill
the reservoir f with air under high pressure say 50 to 100 lbs. per sq. inch.
I find that mixtures of air and light carburetted hydrogen in which the proportions
of gas is from 10 to 17 per cent., are violently explosive and that the above described
means suffices to indicate the presence of any explosive gas regardless of the per cent.
in a manner that is perceptible to the most ignorant and inattentive workmen or
attendants and with apparatus that the most unskilled workman can operate without
danger to himself and attendants and without impairing its efficiency.
As before stated it is intended that each part of the mine required to be tested
shall be provided with a separate tube, and automatic gas testing and indicating
contrivance of the character aforesaid described, all under the control of one operator
at the testing station, so that all parts of the mine are under constant supervision
and constant accurate and infallible tests of the air or gases in each part of the mine
are made and the miners are in constant communication by the combined system of
signalling causing the central station to work not unlike a telephone exchange,
in ready communication with all working parts of the mines enabling the super-
intendent to have reports at short intervals of gas tests and to give orders and to receive
answers and to know the working of each section of the mines without the usual
unavoidable and often fatal delays attending the use of testing means and the special
messenger system heretofore employed.
The signal chart hereto annexed shows an acceptable and convenient code of signals
applicable to mine use in which the wants of the miner is anticipated and any other
important signal can be substituted without interfering with the system here provided.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed I declare that what I claim is
1. In an apparatus for testing gases of mines a series of automatic testing devices
arranged at a testing station a series of pipes each extending from a mine chamber
to one of the testers and a pump whereby a continuous stream of gas is caused to pass
from each chamber to each tester all substantially as set forth.
2. The combination in an apparatus for testing gases of mines of a series of
automatic testing devices at a station each having an igniter a series of pipes each
leading from one of the mine chambers to one of said apparatus and a pump
whereby the gases are caused to pass from each chamber to each tester all substantially
as set forth.
3. The combination of a tube leading from a mine chamber a pump for propelling
the air through said tube a gun connected by a pipe with said tube to receive a
portion of the air thus withdrawn from the mine and an igniter whereby the contents
of the gun are fired when the same are explosive substantially as described.
4. The testing apparatus consisting of a hollow cylinder or gun receiving the
air or gas to be tested a port at one end an igniter opposite to said port and a
movable pision arranged to operate an audible alarm when the charge in the gun
is fired substantially as described.
5. The combination of a cylinder a tube for conducting thereto gases to be tested
a piston sliding in the cylinders a gong arranged to be struck on the outward
movement of the piston and an igniter arranged opposite an exit port of the cylinder
substantially as described.
6. The combination of the testing cylinder provided with an exit port and valve
at one end an igniter opposite said port a sliding piston in the cylinder a spring
retracting said piston a gong arranged to be sounded on the movement of the piston
and an indicator arranged to be moved on the explosion of gases in the cylinder
substantially as described.
7. The testing cylinder provided with a port covered by a hinged indicating arm
combined with a gas inlet escape and igniter, substantially as and for the purpose
set forth.

page_text: 8. The combination of the testing apparatus substantially as described and a tube
extending into the mine and provided at the inner end with a flexible section and
means for suspending the end thereof in an elevated position substantially as and for
the purpose set forth.
9. The combination of the tester a tube extending into the mine a terminal
flexible section and a nozzle constructed to be secured in an elevated position substan-
tially as described.
10. The combination of the tester a tube extending into the mine a whistle secured
to said tube and means for propelling the air outward and backward in said tube
substantially as and for the purpose described.
11. The combination of the tester a tube extending X into the mine a whistle at the
inner end of the tube, a pump for driving the air outward through said tube an
air reservoir and a valve whereby the air reservoir may be put into communication
with the tube to drive a current of air back through the same substantially as and
for the purpose set forth.
12. The combination of the tube a testing apparatus at one end a whistle at the
other a pump an air reservoir and a valve whereby to cut off the pump from
communication with the tube and put the latter into communication with the reservoir
substantially as set forth.
13. The combination of the tester a tube leading to the mine, a chamber, a pump,
an air reservoir, a whistle adjacent to the tester, a valve controlling the flow of air
from the reservoir to the whistle and a chamber covered by a flexible diaphragm
connected to the valve and communicating with the tube substantially as described.
14. The combination with the tester of a tube, a pump a pressure apparatus
communicating with the tube and connected to operate a valve a whistle and a port
controlled by said valve for the passage of air to the whistle, substantially as
described.
15. The combination of the tube a tester, a whistle at the outer end of the tube, an
air reservoir, and a valve and connections constructed to control the flow of air to the
outer whistle according to the pressure in the tube, and a second valve constructed
to control the flow of air between said tube and the pump and between said reservoir
and the tube substantially as described.
16. The system of mine signals set forth or any substantially the same whereby
to signal back and forth by a signalling apparatus all substantially as described.
17. The card containing signals arranged substantially as shown and set forth for
the purpose specified.
18. The general construction and arrangement of the several parts and combinations
herein before set forth for the purpose specified.

page_text: Date of Application, 8th Mar., 1887.
Complete Left, 2nd June, 1887.
Complete Accepted, 26th July, 1887.
Improved Method of and Apparatus for Testing Gases Drawn from
Mines and Signalling or Indicating the Result thereof, and for
General Signalling in Mines.
I, THOMAS SHAW of the City and County of Philadelphia, and State of Pennsylvania
United States of America, Mechanical Engineer do hereby declare the nature of this
invention to be as follows:-
―
This invention consists in the device for automatically testing mine gases combined
with an ordinary tube for conducting the gases to said device which tube is combined
and operated by alternating partial vacuum and high pressure air or gas currents
to produce signals all operating in the manner and for the purpose hereinafter
described.
The object of the invention is to give positive automatic tests of explosive gases
from mines and to give and to receive signals from all parts of the mines desired as
hereinafter explained.
When explosive gases or gases which on combining with air form explosive gases
first enter a mine or a chamber therein they rise to the upper part of the chamber
and gradually fill the latter from the top and through diffusion will mix with the
upper strata of air in explosive proportions working from the top downward so that
the lower strata of air in which the men work will only indicate danger after the
chamber is so full of gas that it is difficult to avoid the consequences of its
presence.
Attempts are made by Inspectors to test the gases by elevating safety or indicating
lamps to the tops of the mine chambers by poles and otherwise but they are then so
far removed from the Inspector that it is impossible for him to correctly ascertain the
indications except when the lamp is extinguished by the explosive gases, creating an
explosive effect within the lamp which is regarded as highly dangerous to the
Inspector and occupants of the mines. The test by lamps is at best of an extremely
negative character under favourable circumstances, whilst under unfavourable circum-
stances such as daily occur in mines, the test is made at peril of life and is very
unreliable.

page_text: Any means of remedying these difficulties and affording a sure and immediate
positive indication of the presence of explosive gases must be of such a character as to
be practically employed by unskilled labor and not liable to get out of order or to
become useless from the necessary rough usage to which the same is subjected in
mines.
The means devised to meet the requirements specified consist of a pipe leading from
a high point in the chamber of the mine to the surface.
The pipe is put in communication with an exhaust pump and a small pipe from the
latter leads to a metallic gun or cylinder having a contracted opening at one side
opposite a flame or incandescent igniter and at one end a loose piston valve opposite a
gong with a spring for retracting the piston valve.
If the pump is put in operation the air will be exhausted from the pipe leading to
the chamber by the pump and will be drawn from the top of the chamber and forced
through the gun.
So long as air alone is thus conducted no other effect results but should a gas
which is explosive or an explosive mixture of air and gas be drawn into the tube and
forced into the gun it will upon meeting the flame be ignited and the charge within
the gun will explode driving the piston valve outward against the gong and sound the
latter in a loud and positive manner. The presence of dangerous gas is thus auto-
matically indicated in a few moments after it begins to enter any chamber and long
before it can accumulate in dangerous quantities and be brought in contact with lights
at lower levels, where men are working etcetera.
A separate pipe leads from each working chamber of the mine to a separate gun or
indicator at the surface.
As will hereinafter be explained each gun is provided with means as a self closing
valve or contracted passage way to prevent the gas and flame from travelling back to
the mine chamber and it will be understood that the parts may be variously con-
structed to automatically propel and conduct the gases and afford an automatic
indication of their presence. For instance the pump may be constructed in different
ways. The gas may be ignited by an incandescent body a flame or an electric spark,
the indicator instead of being a gong may be a piece of travelling paper which is
punched by the piston or the gases may be blown against a chemically prepared
surface which becomes coloured only on the presence of dangerous gas. In either
case however it will be seen that there is a constant automatic withdrawal of gas or
air from an elevated point in each working chamber of the mine and the character of
the gas thus withdrawn is indicated at the surface in a manner to convey immediate
information to the attendants at a central point. While the apparatus having the
general features specified will effect the indications at the surface of the character of
gas in the mine it has the further advantage of also affording means of signalling
from the central station and back to the chamber. Thus by obstructing the flow of
air to the pump or by reversing the current by air pressure from another pump or a
reservoir through the pipe leading into the chamber the current may be forced back
through the said pipe and out of the inner end through a whistle or other alarm
device at said end and by closing the inner end of the pipe by compressing an elastic
portion say a rubber tube by the fingers a partial vacuum is formed in said pipe and
is made the means of sounding a whistle or alarm at the central station. Having
stated the general features of this invention I will now set forth in detail the con-
struction of the various parts as I have used them it being understood however that
such constructions may be greatly varied without departing from the essential features
of this invention.
The pipes leading from the different chambers are conducted to an engine house or
central office within which is arranged the indicating and signalling apparatus con-
sisting of a framework supporting two tables placed one above the other the upper of
which carries the " tester apparatus.
The gun is a hollow cylinder and the piston thereof constitutes also a valve closing
the rear end of the cylinder and held in its closed position by bow springs which press
the piston valve inward the explosion driving it outward against a gong.
At the

page_text: middle portion of the cylinder is a valve box containing a valve hinged on its lower
edge to fall inward against a stop arm limiting the width of the opening and closing
outward on each explosion in the gun or cylinder. The purpose of the valve is to
cause the explosive effect to exert all its force on the piston valve. Beyond the port
of the valve is a short tube or nozzle which leads the gas from the valve port. to the
flame of a lamp the said nozzle is contracted to about one third its diameter at the
outer end to cause wave puffs of explosive gases that are favorable for ignition of
gases of low explosive effect.
There is a port in the top of the valve box of the cylinder and a hinged arm falls
over the same so as to be swung back when an explosion occurs thereby indicating to
the attendant the signalling device which has been operated by the explosion of
dangerous gases.
Such indicator is generally advisable as two signals may be simultaneously operated
in a gang of a dozen or more and without such indication the attendant would be at a
loss to determine the chamber in which the gases are present.
The gases are driven into the gun through a small pipe communicating with a
rotary pump or blower and when an explosive gas or mixture of gas and air is thus
introduced it flows out of the igniter port and is ignited the force of the explosion
closing the valve and forcing out the piston valve against the gong and throwing
back the indicator and this will be repeated at short intervals so long as repeated
charges of explosive gas are introduced into the gun. The entire amount of gas
drawn from the chamber by the pump is not thrown into the gun but the pump is
provided with an overflow pipe through which the surplus gas escapes the amount of
escape being controlled by a valve.
In order to permit of the end of pipe leading from the chamber being readily
carried to the top of the mine chamber and there secured such end is provided with a
flexible terminal pipe and at the end of this flexible section is secured a nozzle
provided with an eye by means of which to suspend it in an elevated position or to
secure a cord for raising and lowering it and at the end of the nozzle is placed an
ordinary whistle. A valve casing containing a valve opening inward and covered by
wire cloth to keep out dirt communicates with the nozzles so as to admit the air or
gases through the nozzle to the conducting pipe when the pump is started.
When a
reverse current is sent through the pump from the central station the whistle is
sounded and by intermitting the current distinct sounds may be made in accordance
with any desired prearranged system as hereinafter set forth so as to afford a means
of sending messages of any character back into the mines.
The reverse current may be forced back by the pump but a reservoir containing air
under pressure and a valve device is preferable whereby to cut off the flow to the
pump through the pipe and at the same time put the reservoir into communication
with the pipe to send a reverse current in the pipe leading to the chamber above
mentioned.
The valve device is in the line of the chamber pipe and consists of valve casing
arranged to cover a common D valve and two ports in the tube passage between the
two tube sections. The casing of the valve device is connected by a pipe with the
reservoir. The valve is actuated by moving a hand lever and when the lever is
depressed it rotates a shaft and an inner arm on the said shaft and connected with the
valve shifts the same. A weight or spring connected with a wire rod brings the valve
back to the normal position. When the valve is in the proper position for testing the
gas the air current Hows uninterruptedly from the mine chamber to the pump. When
it is desired to reverse the current in the tube for the purpose of signalling back to
the mines the valve is placed in the proper position which closes the port to the pump
and opens the other port so that air can pass to the whistle in the mine and their
sound the signal alarm after which the valve when the hand is removed immediately
recovers its normal position and the air passes to the
pump and gun.
Thus as soon as the attendant at the central station is automatically notified by the
signal device that there is dangerous gas in a chamber he can send a down current

page_text: through the chamber pipe and at once notify the miners of their danger or send
desired instructions.
The apparatus is also provided with a means of signalling from the mine to the
station above the ground. The variation of pressure in the pipe is made the means of
admitting air to a whistle at the station and the compressing of the flexible
tube of the chamber pipe will serve to prevent the flow of air or gas from the
mine and thus cause an exhaust or partial vacuum vary the pressure and make the
signal.
The device actuated by the varying pressure to cause the signal may consist of a
metallic casing secured beneath the table by pillar supports; the chamber portion
contains a diaphragm of sheet rubber secured between two discs the outer edge of the
diaphragm is clamped at the edge between the two parts of the casing. In the centre
of said diaphragm is secured a valve stem which passes through an ordinary
packing to the valve casing and there carries a common slide valve covering a port
which leads to the pipe of the whistle. The diaphragm is connected by a link to a
pivoted weighted lever. A tube leads to the casing from the air pressure cylinder so
that high pressure air is always present in valve chamber. A tube is connected with
the tube from the mines so that when the rotary pump is working there is a constant
partial vacuum on the under side of the diaphragmn tending to draw it downward
which is counteracted by an excess of weight on the lever which forms a balance with
excess on the weight side so that when the elastic tube is closed by pressure of the
fingers a vacuum of greater intensity is produced drawing said diaphragm downward
uncovering the port and permitting air to pass from the reservoir and pipe and thus
sound the whistle which sound ceases after the compression of the tube ceases.
signals are sent from the mines to the station above actuated by power at the upper
end and by alternately compressing and releasing the elastic pipe a series of signals
may be made according to any predetermined system which will enable the miners to
send any desired information to the central station.
Thus
To prevent any confusion of signals cach whistle is provided with a hinged indicator
which is thrown backward by the current of air and indicates that the whistle has been
sounded.
The construction of signalling and indicating and blowing apparatus is not limited
as any skilled mechanic will be able to supply differently constructed devices which
will effect the desired results.
As before stated it is intended that each part of the mine required to be tested shall
be provided with a separate tube and automatic gas testing and indicating contrivance
of the character fore described, all under the control of one operator at the testing
station so that all parts of the mine are under constant supervision, and constant
accurate and infallible tests of the air or gases in each part of the mine are made and
the miners are in constant communication by the combined system of signalling
causing the central station to work not unlike a telephone exchange in ready com-
munication with all working parts of the mines enabling the superintendent to have
reports at short intervals of gas tests and to give orders and to receive answers and to
know the working of each section of the mines without the usual unavoidable and
often fatal delays attending the use of testing means and the special messenger system
heretofore employed.
T
ג
1 1327

page_text: far removed from the inspector that it is impossible for him to correctly ascertain the
indications except when the lamp is extinguished by the explosive gases creating an
explosive effect within the lamp which is regarded as highly dangerous to the
inspector and occupants of the mine. The test by lamps is at best of an extremely
negative character under favorable circumstances whilst under unfavorable circumstances
such as daily occur in mines the test is made at the peril of life and is very unreliable.
Any means of remedying these difficulties and affording a sure and immediate
positive indication of the presence of explosive gases must be of such a character as to
be practically employed by unskilled labor and not liable to get out of order, or to
become useless from the necessary rough usage to which the same is subjected in
mines.
The means I have devised meet the requirements I have specified and can best be
understood in their general features by reference to the diagram Fig. 15.
In said diagram a represents one of the chambers of the mine; ", the vertical
shaft a communicating level or gallery and a pipe leading from a high point in
the chamber all to the surface.
The pipe b is put in communication with an exhaust pump g" and a small pipe
from the latter leads to a metallic gun or cylinder p having a contracted opening at
one side opposite a flame or incandescent igniter w and at one end a loose piston
valve S opposite a gong v with a spring for retracting the piston valve.
If the pump is now put in operation the air will be exhausted from the pipe b by
the pump and will be drawn from the top of the chamber a¹ and forced through the
gun p.
So long as air alone is thus conducted no other effect results, but should a gas
which is explosive or an explosive mixture of air and gas be drawn into the tube b
and forced into the gun p it will upon meeting the flame we be ignited and the charge
within the gun will explode driving the piston valve outward against the gong and
sound the latter in a loud and positive manner. The presence of dangerous gas is
thus automatically indicated in a few moments after it begins to enter any chamber
and long before it can accumulate in dangerous quantities and be brought in contact
with lights at lower levels where men are working etc.
A separate pipe leads from each working chamber of the mine to a separate gun or
indicator at the surface.
of
As will hereinafter be explained each gun is provided with means such as a self
closing valve or contracted passage way to prevent the gas and flame from travelling
back to the mine chamber, and it will be understood that the parts indicated in said
diagram may be variously constructed to automatically propel and conduct the gases
and afford an automatic indication of their presence. For instance the pump may be
constructed in different ways, the gas may be ignited by an incandescent body a flame
or an electric spark the indicator v instead of being a gong may be a piece of
travelling paper which is punched by the piston or the gases may be blown against a
chemically prepared surface which becomes colored only on the presence
dangerous gas. In either case however it will be seen that there is a constant
automatic withdrawal of gas or air from an elevated point in each working chamber
of the mine and the character of the gas thus withdrawn is indicated at the surface in
a manner to convey immediate information to the attendants at a central point.
While the apparatus having the general features specified will effect the indications at
the surface of the character of gas in the mine it has the further advantage of also
affording means of signalling from the central station and back to the chamber. Thus
by obstructing the flow of air to the pump g or by reversing the current by air
pressure from another pump or a reservoir through the pipe b, the current may be
forced back through the pipe b and out of the inner end through a whistle or other
alarm device at said end and by closing the inner end of pipe by compressing an
elastic portion say a rubber tube, by the fingers, a partial vacuum is formed in said
pipe and is made the means of sounding a whistle or alarm at the central station.
Having stated the general features of my invention I will now set forth in detail the
construction of the various parts as I have used them, it being understood however

page_text: that such constructions may be greatly varied without departing from the essential
features of my invention.
In fig. 11 the central station is shown as arranged in an engine house or central
office to which all the pipes p" lead from the different chambers of the mine.
Within this house is arranged the indicating and signalling apparatus more fully
illustrated in figs. 6, 7, 9, 10, 12, 13 and 14 and in figs. 1 to 5. Said apparatus is
supported by a frame work having two platforms or tables c¹ and ¹¹.
On the tables e figs. 10 and 13 is supported the tester p the construction of which
is more fully illustrated in figure 6.
The gun is a hollow cylinder and the piston S constitutes also a valve closing the
rear end of the cylinder and held in its closed position by the bow springs t, which
press the piston valve S inward the explosion driving it outward against the gong v.
At the middle portion of the cylinder is a valve box shown in section in fig. 7 con-
taining a hinged valve y hinged on its lower edge to fall inward against the stop arm
shown in fig. 7 limiting the width of the opening and closing outward on each
explosion in the gun or cylinder. The purpose of the valve is to cause the explosive
effect to exert all its force on the piston valve S. Beyond the port of the valvey is a
short tube or nozzle Z which leads the gas from the valve port to the flame of a lamp w
the said nozzle Z is contracted to about one third its diameter at the outer end to
cause wave puffs of explosive gases that are favorable for ignition of gases of low
explosive effect.
There is a port in the top of the valve box of the cylinder, and a hinged arm a¹
falls over the same so as to be swung back to the position shown in dotted lines fig. 6,
when an explosion occurs thereby indicating to the attendant the signalling device
which has been operated by the explosion of dangerous gases.
Such indicator is generally advisable as two signals may be simultaneously operated
in a gang of a dozen or more and without such indication the attendant would be at a
loss to determine the chamber in which the gases are present.
The gases are driven into the gun p through the small pipe figs. 7, 10, and 14,
communicating with the rotary pump or blower g" and when an explosive gas or
mixture of gas and air is thus introduced it flows out of the igniter port and is ignited
the force of the explosion closing the valve y and forcing out the piston valve S against
the gong and throwing back the indicator a' and this will be repeated at short
intervals so long as repeated charges of explosive gas are introduced into the gun.
The entire amount of gas drawn from the chamber by the pump is not thrown into
the gun but I provide the pump with an overflow pipe through which the surplus
gas escapes, a valve at el, fig. 10, controlling the amount of escape.
In order to permit the end of pipe b, fig. 15, to be readily carried to the top of the
mine chamber and there secured I provide such end with a flexible terminal pipe f
(fig. S) and at the end of this flexible section 1 secure a nozzle el, provided with an
eye e by means of which to suspend it in an elevated position or to secure a cord for
raising and lowering it, and at the end of the nozzle I place an ordinary whistle d'.
A valve casing containing a valve h¹ opening inward and covered by wire cloth g¹ to
keep out dirt communicates with the nozzles so as to admit the air or gases through
the nozzle to the conducting pipe when the pump is started. When a reverse current
is sent through the pump from the central station the whistle is sounded and by inter-
mitting the current distinct sounds may be made in accordance with any desired
prearranged system as hereinafter set forth so as to afford a means of sending messages
of any character back into the mines.
The reverse current may be forced back by the pump but I prefer to use a
reservoir containing air under pressure and a valve device (figs. 1, 2, 3, 4, 5, 10, 13
and 14) whereby to cut off the flow to the pump through the pipe c and at the
same time put the reservoir" into communication with the pipe to send a reverse
current in pipe b.
In the construction shown the valve device (figs. 13 and 14) is in the line of pipe b
and consists of valve casing a (figs. 1 to 5) arranged to cover a common D-valve n
and two ports & and in the tube passage between the two tube sections b, c. The

page_text: casing of the valve device is connected by a pipe d with the reservoir f". The
valve is actuated by moving a hand lever e, when the lever is depressed to the posi-
tion shown in dotted lines fig. 1, it rotates the shaft and an inner arm m on the
shaft and connected with the valve shifts the same from over the port & to the position
shown in figure 5. A weight or Spring connected with a wire rod g brings the valve
back to the normal position shown in figure 4.
The pipe b connects with the mine chamber and the pipe c to the pump and
the pipe to the reservoir / containing air under pressure. When the valve
is in the position fig. 4, which is the proper position for testing the gas the air
current flows uninterruptedly from the mine chamber through the pipe 6 port k
valve n and port and pipe e to the pump. When it is desired to reverse the current
in the tube for the purpose of signalling back to the mines the valve is placed
in the position fig. 5, which closes the port to the pump and opens the port. k so
that air can pass through the pipe d, casing a and through the pipe b to the
whistled in the mine and there sound the signal alarm after which the valve when
the hand is removed immediately recovers its normal position, fig. 4, and the air
passes to the pump and gun.
Thus as soon as the attendant at the central station is automatically notified by the
signal device that there is dangerous gas in a chamber he can by depressing the valve
lever e, send a down current through the pipe band at once notify the miners of
their danger or send desired instructions.
The apparatus is also provided with a means of signalling from the mine to the
station above the ground. The variation of pressure in the pipe is made the means
of admitting air to a whistle a" (figs. 10, 12, 13 14) at the station and the compressing
of the flexible tube, fig. 8, of the pipe will serve to prevent the flow of air or gas
from the mine and thus cause an exhaust or partial vacuum, vary the pressure and
make the signal.
A device actuated by the varying pressure to cause the signal is shown in figure 9.
A metallic casing is secured beneath the table e¹ by pillar supports; the chamber
portion contains a diaphragm of sheet rubber secured between two discs S¹ the
outer edge of the diaphragm is clamped at the edge between the two parts of the
casing. In the centre of said diaphragm is secured a valve stem which passes through
an ordinary packing to the valve casing of and there carries a common slide valve
covering a port which leads to the pipe of the whistle a¹¹, figs. 10 and 12. The
diaphragm is connected by a link to a pivotted weighted lever i¹. A tube n' leads
to the casing o¹ from the air pressure cylinder f", fig. 14, so that high pressure
air is always present in valve chamber o¹. A tube m¹ is connected with the tube b
from the mines so that when the rotary pump is working there is a constant partial
vacuum on the under side of the diaphragm Stending to draw it downward which
is counteracted by an excess of weight on the lever which forms a balance with
excess on the weight side so that when the elastic tube figs. I and 8, is closed
by pressure of the fingers a vacuum of greater intensity is produced drawing said
diaphragm downwards uncovering the port and permitting air to pass from the
reservoir and pipe a¹ to the port and thus sound the whistle a" which sound ceases
after the compression of the tube f¹ ceases. Thus signals are sent from the mine
to the station above actuated by power at the upper end and by alternately compressing
and releasing the elastic pipe, a series of signals may be made according to any
predetermined system which will enable the miners to send any desired information
to the central station.
To prevent any confusion of signals each whistle a¹ fig. 12, is provided with
a hinged indicator n which is thrown backward by the current of air and falls in the
position shown in dotted lines which indicates that the whistle has been sounded.
I do not limit myself to the precise construction of signalling and indicating
and blowing apparatus shown as any skilled mechanic will be able to supply
differently constructed devices which will effect the same results as those set forth
which have proved most effective in actual operation.
In the apparatus shown the revolving shaft of the pump is driven by a belt "

page_text: passing around pulleys as shown in figs. 10 and 14 from a shaft to which motion
is imparted from an adjacent driving shaft but this arrangement will be varied when
a differently constructed pump is used. Any ordinary air pump can be used to fill
the reservoir with air under high pressure say 50 to 100 lbs. per sq. inch.
I find that mixtures of air and light carburetted hydrogen in which the proportions
of gas is from 10 to 17 per cent., are violently explosive and that the above described
means suffices to indicate the presence of any explosive gas regardless of the per cent.
in a manner that is perceptible to the most ignorant and inattentive workmen or
attendants and with apparatus that the most unskilled workman can operate without
danger to himself and attendants and without impairing its efficiency.
As before stated it is intended that each part of the mine required to be tested
shall be provided with a separate tube, and automatic gas testing and indicating
contrivance of the character aforesaid described, all under the control of one operator
at the testing station, so that all parts of the mine are under constant supervision
and constant accurate and infallible tests of the air or gases in each part of the mine
are made and the miners are in constant communication by the combined system of
signalling causing the central station to work not unlike a telephone exchange,
in ready communication with all working parts of the mines enabling the super-
intendent to have reports at short intervals of gas tests and to give orders and to receive
answers and to know the working of each section of the mines without the usual
unavoidable and often fatal delays attending the use of testing means and the special
messenger system heretofore employed.
The signal chart hereto annexed shows an acceptable and convenient code of signals
applicable to mine use in which the wants of the niner is anticipated and any other
important signal can be substituted without interfering with the system here provided.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed I declare that what I claim is
1. In an apparatus for testing gases of mines a series of automatic testing devices
arranged at a testing station a series of pipes each extending from a mine chamber
to one of the testers and a pump whereby a continuous stream of gas is caused to pass
from each chamber to each tester all substantially as set forth.
2. The combination in an apparatus for testing gases of mines of a series of
automatic testing devices at a station each having an igniter a series of pipes each
leading from one of the mine chambers to one of said apparatus and a pump
whereby the gases are caused to pass from each chamber to each tester all substantially
as set forth.
3. The combination of a tube leading from a mine chamber a pump for propelling
the air through said tube a gun connected by a pipe with said tube to receive a
portion of the air thus withdrawn from the mine and an igniter whereby the contents
of the gun are fired when the same are explosive substantially as described.
4. The testing apparatus consisting of a hollow cylinder or gun receiving the
air or gas to be tested a port at one end an igniter opposite to said port and a
movable piston arranged to operate an audible alarm when the charge in the gun
is fired substantially as described.
5. The combination of a cylinder a tube for conducting thereto gases to be tested
a piston sliding in the cylinders a gong arranged to be struck on the outward
movement of the piston and an igniter arranged opposite an exit port of the cylinder
substantially as described.
6. The combination of the testing cylinder provided with an exit port and valve
at one end an igniter opposite said port a sliding piston in the cylinder a spring
retracting said piston a gong arranged to be sounded on the movement of the piston
and an indicator arranged to be moved on the explosion of gases in the cylinder
substantially as described.
7. The testing cylinder provided with a port covered by a hinged indicating arm
combined with a gas inlet escape and igniter, substantially as and for the purpose
set forth

page_text: 8. The combination of the testing apparatus substantially as described and a tube
extending. into the mine and provided at the inner end with a flexible section and
means for suspending the end thereof in an elevated position substantially as and for
the purpose set forth.
.
9. The combination of the tester a tube extending into the mine a terminal
flexible section and a nozzle constructed to be secured in an elevated position substan-
tially as described.
10. The combination of the tester a tube extending into the mine a whistle secured
to said tube and means for propelling the air outward and backward in said tube
substantially as and for the purpose described.
11. The combination of the fester a tube extending into the mine a whistle at the
inner end of the tube, a pump for driving the air outward through said tube an
air reservoir and a valve whereby the air reservoir may be put into communication
with the tube to drive a current of air back through the same substantially as and
for the purpose set forth.
12. The combination of the tube a testing apparatus at one end a whistle at the
other a pump an air reservoir and a valve whereby to cut off the pump from
communication with the tube and put the latter into communication with the reservoir
substantially as set forth.
13. The combination of the tester a tube leading to the mine, a chamber, a pump,
an air reservoir, a whistle adjacent to the tester, a valve controlling the flow of air
from the reservoir to the whistle and a chamber covered by a flexible diaphragm
connected to the valve and communicating with the tube substantially as described.
.14. The combination with the tester of a tube, a pump a pressure apparatus
communicating with the tube and connected to operate a valve a whistle and a port
controlled by said valve for the passage of air to the whistle, substantially as
described.
15. The combination of the tube a tester, a whistle at the outer end of the tube, an
air reservoir, and a valve and connections constructed to control the flow of air to the
outer whistle according to the pressure in the tube, and a second valve constructed
to control the flow of air between said tube and the pump and between said reservoir
and the tube substantially as described.
16. The system of mine signals set forth or any substantially the same whereby
to signal back and forth by a signalling apparatus all substantially as described.
17. The card containing signals arranged substantially as shown and set forth for
the purpose specified.
18. The general construction and arrangement of the several parts and combinations
hereinbefore set forth for the purpose specified.
Dated this 2nd day of June 1807