IMPROVE- MENTS IN APPARATUS FOR THE SAFE COMBUSTION OF INFLAMMABLE GAS, AND PROVISIONAL SPECIFICATION AND APPLICABLE FOR MINE LAMPS, FOR INDICATING DANGER, AND FOR SIGNALLING
Year: 1871

page_text: LETTERS PATENT to Archibald Kennedy Irvine, of Glasgow, in the
County of Lanark, North Britain, for the Invention of "IMPROVE-
MENTS IN APPARATUS FOR THE SAFE COMBUSTION OF INFLAMMABLE GAS, AND
PROVISIONAL SPECIFICATION left by the said Archibald Kennedy
Irvine at the Office of the Commissioners of Patents, with his
Petition, on the 20th July 1871.
I, ARCHIBALD KENNEDY IRVINE, of Glasgow, in the County of
Lanark, North Britain, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN APPARATUS FOR THE SAFE COMBUSTION OF
INFLAMMABLE GAS, AND APPLICABLE FOR MINE LAMPS, FOR INDICATING DANGER,
AND FOR SIGNALLING," to be as follows, that is to say :-
This Invention relates to the safe combustion of inflammable gas
when mixed with air as in mines, and is applicable to lamps, to danger
indicators, and for signalling.

page_text: As applied to a lamp the Invention consists in forming an inlet for
air in the bottom of the flame chamber, such inlet being covered with
wire gauze or other suitable permeable material, whilst the sides of the
chamber are made close and impermeable or nearly so. The wick tube
is arranged by preference in the centre of the air inlet, and the oil
reservoir and bottom of the lamp are constructed in any convenient way,
provided free access for air is arranged in connection with the gauze
inlet disc. The flame will burn silently in the ordinary way as long as
air or an inexplosive mixture of air and gas surrounds the lamp, but
when an explosive mixture of air and gas is present the combustion]
whilst proceeding quite safely will be attended with a loud sound,
which cannot fail to attract attention. A lens is fitted at one side of
the flame chamber for the emission of the light, and can be removed
for examining the condition of the flame, there being a plain glass
fixed within it, which prevents exposure of the flame and also acts as a
safeguard in the event of the lens being accidentally broken.
Apparatus may be made like the lamp and with or without lenses
or glass sides, of any convenient size, and may be used in various
ways for the purposes herein-before indicated. Such apparatus may be
fixed in dangerous positions in mines or in other places where there
may be inflammable gas; or it may be used for safely burning off the
inflammable gas, the products of combustion being led away by pipes or
ducts from the top or chimney when the quantity makes this desirable.
A lamp made as described may be used for making audible signals
wherever ordinary illuminating or other inflammable gas is at hand, as
the sound herein-before referred to will be produced on turning on a
jet of gas beneath the lamp so that such gas may mix with the air
entering the lamp.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Archibald Kennedy Irvine in the Great Seal
Patent Office on the 19th January 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ARCHIBALD
KENNEDY IRVINE, of Glasgow, in the County of Lanark, North Britain,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her:
Letters Patent, bearing date the Twentieth day of July, in the year of

page_text: our Lord One thousand eight hundred and seventy-one, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Archibald Kennedy Irvine, Her special
licence that I, the said Archibald Kennedy Irvine, my executors,
administrators, and assigns, or such others as I, the said Archibald
Kennedy Irvine, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all
times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN APPARATUS FOR THE SAFE COMBUSTION OF
INFLAMMABLE GAS, AND APPLICABLE FOR MINE LAMPS, FOR INDICATING DANGER,
AND FOR SIGNALLING," upon the condition (amongst others) that I, the
said Archibald Kennedy Irvine, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
> Patent.
NOW KNOW YE, that I, the said Archibald Kennedy Irvine, do
hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement in writing, reference being had to the
accompanying Drawings, that is to say:-
My said Invention relates to the safe combustion of inflammable gas
or vapor when mixed with air as in mines, and is applicable to lamps,
to danger indicators, and for signalling.
An important part of my Invention consists in practically applying
and using sound due to the presence of certain mixtures of inflammable
gas and air, and caused in a manner analogous to the action in the
scientific experiment known as the "singing flame" or otherwise.
And in order that my said Invention and the manner of performing
the same may be properly understood I hereunto append two Sheets of
5 explanatory Drawings to be herein-after referred to, and representing
various modifications of apparatus designed for the practical appli-
cation of my Invention in mines. In these Drawings the same reference

page_text: numerals are used to mark the same or like parts wherever they are
repeated.
Figure 1 on Sheet 1 of the Drawings is a plan of the lower part of
one of my "singing safety mine lamps;" and Figure 2 is a vertical
section of the entire lamp. This lamp is contrived to avoid as much
as possible the heating of the oil reservoir 1 without placing such
reservoir at one side, and is suitable for burning a comparatively
volatile oil, such as paraffin oil. An inlet 2 for air is formed in
the bottom of the flame chamber 3, and is covered with wire gauze
(colored blue in Figure 2) or with finely perforated metal or other
suitable permeable material, whilst the sides of the chamber 3 are made
close and impermeable or nearly so.
The wick tube 4 is arranged by
preference in the centre of the air inlet 2, and the oil reservoir 1 is
constructed and connected to the upper part of the lamp in such a way
as to allow free access for air to the gauze inlet disc at 2. The air
inlet 2 is formed in the middle of an annular disc 5, which is connected
by rods 6 to a ring or flange 7 fitting round the bottom edge of the
oil reservoir, a space being thus formed between the disc 5 and the top
of the oil reservoir 1, to which the air has access all round through an
external precautionary shell of wire gauze 8. A dome 9 common
to paraffin oil lamps is shown as applied over the wick, being held by
narrow strips of metal fixed to the top of the disc 5, whilst an enclosed
pinion 10 is applied for raising or lowering the wick, the spindle 11 of
the pinion being led to the outside of the lamp through a close fitting
tube through which flame cannot pass. This tube is continued across
so as to steady the wick tube 4 to which it is fixed. As a precaution
to prevent flame from penetrating along by the wick into the oil
reservoir 1, the wick is enclosed in a bag 12 of wire gauze or other
suitable permeable material. The sides of the flame chamber 3 and
of the chimney 13 above it are made in one continuous conical form of
impermeable sheet metal (preferably copper). A lens 14 is shown as
applied at one side for the emission of the light, this lens being by pre-
ference held in a metal ring 15 so as to be removable although fitting
tightly in its place, whilst beneath the lens there is a permanently fixed
piece of plate glass 16, and beneath the piece 16 a thinner piece 17.
The lens 14 is made removable so that it can be used or not as desired,
whilst the thin glass 17 is provided to afford temporary protection in
the event of the other glass 16 being accidentally broken. If desired
wire gauze or mica may be interposed between or placed outside of

page_text: the glasses as an additional precaution. A curved deflecting cap 18 is
fixed by means of three metal strips above the chimney 13, and is made
of the peculiar form shown in order without too much impeding or
producing eddies in the current to retain a certain quantity of the
uninflammable products of combustion and so reduce to a minimum the
possibility of flame communicating with the outside through the top
of the lamp. The cap 18 also prevents a current of air or gas from
blowing down into the lamp, and as an external current cannot in any
way act injuriously on the lamp it is safer than the common Davy,
the flame of which is admittedly liable to be carried through the wire
gauze by a strong blast or current of air and gas. A hood 19 of wire
gauze is fixed over and round the chimney, and if wished and when
the singing action is not so much an object this hood may be made of
two or more thicknesses, provided that its superficial area is corre-
spondingly increased in order to allow sufficient egress for the products
of combustion. The lamp is shown with a handle 20 fitted to the
side, but in addition thereto or instead thereof the ordinary suspension
ring may be applied at the top. The shell of the flame chamber 3
has fixed to its bottom a flat ring 23 formed with button holes, as
indicated by dotted lines in Figure 1, so as to lock after the manner
of a bayonet joint upon buttons 33 fixed in the ring 5, and is prevented
from unlocking by a screw 34. The oil reservoir 1 is connected to
the ring 7 also by a bayonet joint, and is removable downwards after
turning it round to a certain point. When lowered it leaves the wick
bag 12 and wick tube 4 suspended and can be filled with oil at its
central opening. This lamp is in no respect inferior to the ordinary
Davy, whilst it has in addition the valuable and remarkable property
that whereas the flame will burn silently in the ordinary way so long
as air or an inexplosive mixture of air and gas surrounds the lamp,
yet when the inflammable gas mixed with the air attains a certain
proportion which is explosive, the combustion whilst proceeding quite
safely will be attended with a loud sound, which cannot fail to attract
attention. This sound is generally of a musical character and is much
louder than and not to be confounded with a crackling" or slight
sound produced in the Davy by the entrance of fire-damp.
My improved lamp is otherwise, safer than the Davy, because the
current at the inlet tends to prevent the flame from passing downwards
or towards the sides. Only a limited quantity of the fire-damp can

page_text: enter, and is burned immediately after entering producing carbonic
acid, which occupying the interior makes the communication of flame
next to impossible.
Figure 3 is a horizontal section, and Figure 4 is a vertical section
of a second modification of my "singing safety mine lamp," which is
adapted for burning train or other common oil used in mine lamps.
It is very suitable for the examination of a mine, and to test the state
of the atmosphere. The oil reservoir 1 is made in an annular form,
so that the air has access from below up through it to the annular
gauze covered inlet 2 into the flame chamber 3, whilst the wick tube 4
is fitted into a bent tube 21 shaped to lead the oil from the reservoir 1
up to the centre of the lamp. The flame chamber 3 is made cylindrical,
and for the emission of the light there is a window of mica a
wire gauze covering being applied to the mica as a protection. The
chimney 13 is made conoidal, and it is surmounted by a curved cap 18,
and covered by an external wire gauze hood 19, as in the first
modification.
Figure 5 is a horizontal section, and Figure 6 is a vertical section
showing the lower part of a third modification, which differs from the
second in having a slightly different form of wick tube 4 and in some
minor constructive details, which will be easily understood from the
Drawing. A wick trimmer 22 is shown somewhat like what is used in
common mine lamps, but provision is made for obtaining a better action,
a slot being made in the side of the wick tube 4 a little below its top
to admit a sickle-shaped horizontal part of the trimmer 22, which by
turning the trimmer can be made to grasp the whole of the wick, and
raise or lower it with certainty.
A suitable wick trimmer (10 or 22) is to be understood as applied
to every modification of my lamp, although it may not be shown in
some of the Figures.
Lamps which like the second and third modifications are constructed
to admit the air up through the bottom of the oil reservoir 1 may be
provided with a precautionary covering of wire gauze over the bottom
opening, as indicated in Figure 4; and such lamps must be provided
with feet so that air may enter beneath when the lamp is set on a
table or flat surface. A bent tube 35 is provided to be inserted as
indicated by dotted lines in Figure 6 in the air aperture in the bottom
of the oil reservoir 1, and with its outer end carried up above the lamp.

page_text: This tube affords a convenient means of testing the air near the roof
of a mine, as the lamp will draw its supply down the tube. The top
of the tube may be directed vertically as shown, or it may be bent and
directed horizontally. Similar tubes of any convenient length may be
applied for leading to the lamps air or mixed air and gas from more
or less distant points.
Figure 7 is a horizontal section, and Figure 8 is a vertical section of
a fourth modification, which whilst it is adapted for common oil and
wicks has the space for the entrance of air arranged somewhat as in
the first modification. The flange or flat ring 23, to which the shell
of the flame chamber 3 is attached, is formed with a deep cylindrical
part 24, the lower portion of which screws upon the oil reservoir 1.
Holes are made all round through the cylindrical part 24 (which may
be covered with wire gauze as a precaution), and the air enters by these
holes to an internal space leading to the annular gauze-covered inlet 2
into the flame chamber 3.
It is one advantage of my improved lamps that the arrangement of
the inlet and chimney produce a better draught and thereby make the
light better than in ordinary mine lamps.
Figures 9 and 10 on Sheet 2 of the Drawings are sectional elevations
as at right angles to each other of a fifth modification, intended more
especially for indicating the presence of inflammable gas in the air
surrounding the apparatus. This apparatus is designed to be very
sensitive, and so as to give an audible indication when there is mixed
with the air a smaller proportion of inflammable gas than will produce
sound in the modifications herem-before described, and for this purpose
advantage is taken of the fact that the presence of inflammable gas
amongst the air entering causes a considerably increased heat in the flame
chamber 3, not only when the proportion is sufficient to make the lamp
or apparatus sing, but also when the proportion is less than that.
The apparatus is provided with a central wick and wick tube 4
supplied with ordinary oil from a fountain reservoir 25 by a pipe 26
fitted with a stop-cock. The wick tube 4 is encircled in a tube 27
supplied with naphtha or other suitable volatile spirit from a fountain
reservoir 28 by a pipe 29 fitted with a stop-cock. The naphtha pipe 29
communicates by a branch pipe 30 with a closed annular tube 31 placed
in the flame chamber 3 centrally at a level a little above the top of the

page_text: wick tube 4. The annular gauze-covered air inlet 2 into the flame
chamber 3 is beneath the tube 31 or boiler as I shall herein-after term it.
Two slightly separated plies of wire gauze are shown at the inlet 2
in this modification, and I may remark that two or more may be
applied in any of the modifications, the lower ply or plies being by
preference of larger area than the top one, so as to increase the
obstruction to the current as little as possible. The additional plies
of wire gauze, however, diminish the singing power of the lamps, but
this action may be counteracted by increasing the height of the chimney.
A cylindrical shell 32 is extended downwards from the ring or dise 5
and forms an annular space round the tube 27, up through which the
air entering the flame chamber 3 must pass. The outside of the tube
27 and the inside of the shell 32 are lined with a cotton fabric or other
suitable fibrous or porous material, and the two linings are connected
by radially disposed vertical webs of the same material, the whole of
which becomes moistened by the naphtha when this overflows, as hercin-
after explained at small holes formed round the otherwise closed top of
the tube 27. When the apparatus is in working order the dip tube
of the naphtha vessel 28 is set below the holes in the top of the tube 27,
but the boiler 31 and branch pipe 30 are full of naphtha. The ordinary
flame is small and does not appreciably heat the boiler 31 when pure
air enters the apparatus, but when even a very small proportion of
inflammable gas is mixed with the air considerable heat is produced
in the flame chamber 3, and causes the expansion and eventually the
This action makes the
evaporation of the naphtha in the boiler 31.
naphtha overflow from the top of the tube 27 and moisten the porous
material inside the shell 32, and the naphtha rapidly evaporating from
this material and its vapor mixing with the air thereby increases the
inflammability of the mixture sufficiently to make the apparatus sing,
and so give the desired audible indication or warning.
The apparatus is represented as without a window, but the upper
part is otherwise similar to that of the modification first herein-before
described.
The heat due to the presence of inflammable gas in the air entering
the apparatus may be made to yield an audible signal otherwise than
Thus the boiler 31 may have a small
as herein-before described.
whistle or other sound producer connected to it to be acted upon by

page_text: on a jet of gas beneath the lamp in a manner to allow the gas to mix
with the air entering the lamp or apparatus.
The fifth modification (Figures 9, 10,) may be made to yield signals
if the dip tube of the naphtha reservoir is made adjustable by setting it
so as to cause the naphtha to overflow from the tube 27, whereupon its
vapor will mix with the air entering the lamp and make it sing; or
the lamp may be placed in connection with a box or vessel containing
fibrous or porous material moistened with naphtha or other suitable
volatile spirit, and the box being contrived so that the air passes
through it to supply the lamp. When the apparatus is made specially 1
for burning gas or vapor in this way it need not be provided with an
oil wick and reservoir, as the mixed air and gas may be ignited above
the wire gauze when required.
Having thus particularly described my said Invention, and the manner
in which the same is to be performed, I have to state that I do not ]
restrict myself to the precise details herein described or delineated; but
that what I believe to be novel and original, and claim as the Invention
secured to me by the herein-before in part recited Letters Patent is, —
1. The arranging or combining together of the parts of mine lamps
or apparatus to be used where inflammable gas or vapor is mixed with
the air in the improved modes, substantially as herein described and
delineated.
2. The adapting of lamps or apparatus to indicate the presence of
certain proportions of inflammable gas or vapor in air by sound, sub-
stantially in the manner herein-before described.
3. The making of the lamps or apparatus with the only inlet for air
through wire gauze or other suitable permeable material near the level
of the bottom of the flame, and with the outlet for the products of
combustion at the top of an otherwise close chimney, as herein-before
described.
4. The making of the oil reservoirs and parts in immediate connection
therewith in the forms shown in Figures 1 to 6 and herein-before
described.
5. The applying of the deflecting cap 18 at the top of the chimney
as and for the purposes herein-before described.
6. The applying of the tube 35 as and for the purposes herein-before

page_text: 7. The making the apparatus indicate by sound the presence of com-
paratively small proportions of inflammable gas or vapor by means
substantially such as are herein-before described with reference to
Figures 9 and 10.
8. The using of sound producing apparatus substantially such as is
herein-before described for signalling.
In witness whereof, I, the said Archibald Kennedy Irvine, have
hereunto set my hand and seal, this Eighteenth day of January,
in the year of our Lord One thousand eight hundred and
seventy-two.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
A. K. IRVINE. (L.S.)