MENTS IN THE MODE OF UTILIZING AND INCREASING THE LIGHTING POWER OF GASES AND INFLAMMABLE VAPORS, AND IN APPARATUS CONNECTED THEREWITH
Year: 1868

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery
Lane, in the County of Middlesex, for the Invention of
MENTS IN THE MODE OF UTILIZING AND INCREASING THE LIGHTING POWER
OF GASES AND INFLAMMABLE VAPORS, AND IN APPARATUS CONNECTED
THEREWITH."-A communication from abroad by Edouard Armand
PROVISIONAL SPECIFICATION left by the said Alexander Melvillo
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 1st February 1868.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE MODE OF UTILIZING AND INCREASING THE LIGHTING
POWER OF GASES AND INFLAMMABLE VAPORS, AND IN APPARATUS CONNECTED
THEREWITH," to be as follows:-
This Invention relates, first, to the application of a mixture of gases
or carburetting and inflammable gases for lighting purposes by
projecting them on an infusible body, such as lime, magnesia, or

page_text: platina, which is caused to produce a white light by the ignition of
the gases.
I may use more particularly a mixture of atmospheric air
and lighting gas in the proportion of one part gas to one, two, or three
parts of atmospheric air, or one part of oxygen to two, three, or four
of lighting gas, or I may use a mixture of atmospheric air and oxygen,
or protoxide of azote and lighting gas, to be in all cases however
inexplosive; I also include the use for the above purpose of hydrogen
and protoxide of azote.
Secondly. The Invention relates to the aplication of what is known
as the hydrogen burner with a platinum gallery to this improved mode
of lighting, or I may if desired dispense with the burner and perforated
gallery of platinum and substitute a burner of porcelain or steatite
or other apparatus used for heating with a mixture of air and gases.
I dispense with the internal current of air supplied to these burners
as being unnecessary. I would observe that these burners have been
used only for hydrogen gas and never for mixing air with hydrogen.
Thirdly. The Invention relates to a mode of mixing these gases by
the consumer at the meter, so as to supply the mixture to the pipes
without requiring double conduits as hitherto for the Drummond light,
and whereby great oconomy is obtained by dispensing with a double
set of parts.
In order to apply this improved mode of lighting it is only necessary
to change the burners and apply the apparatus for effecting the mixture
to the meter. The mixture may also be made at the manufactory, in
which case the apparatus would be dispensed with. Among the means
for effecting the mixing in defined proportions I use more particularly
two meters mounted on the same axis so as to work together. The
gases or inflammable vapors would enter the one, and the air, oxygen,
protoxide of azote, or other gas or carburetting vapor enters the other.
The two gases are made to enter a small bowl at an angle of about
ninety degrees or thereabout, in this manner the mixture is more readily
effected in determinate proportions; the mixture thence passes to the
pipes after passing if desired through a water or other regulator. As
the double meter could not withstand differences of pressure exceeding
two or three inches in order to burn the gases at pressures of from
I
four to eight inches of water, which I prefer as a suitable limit, propose
to employ a pump in connection with this double meter (to be worked

page_text: by a suitable motor) which forces the mixture into a regulator for giving
it the desired pressure.
The motion of the driving power is regulated by that of the receiver
of the regulator, or instead of this arrangement I may use two pumps
coupled together on the principle of extractors, with the difference that
instead of removing the pressure they produce a pressure equal as
above-mentioned to from four to eight inches of water. One of the
pumps would exhaust the gas from a regulator into which it passes,
while the other pump would take the air direct from the atmosphere,
or it may be the oxygen, protoxide of azote, or other carburetting gas
or vapor employed. These two pumps are driven together by the
same motor, their capacities being regulated according to the proportions
in which the gases are to be mixed, for example, one part of gas to one
of air. A small gas engine would answer the purpose, or two rotary
extractors mounted on the same axis may be used, one for the gas or
inflammable vapor and the other for the gas or carburetting vapor, or
a pump cylinder with pistons may be used, or it may be a bellows or
other means. The apparatus working these two pumps simultaneously
supplies the mixture to a vessel, where it is still more intimately mixed,
and thence to a water or other regulator; this latter regulates the
motion of the apparatus driving the pumps in such manner as to afford
a just sufficient supply of the mixed gas for consumption. The gas on
leaving the generator passes through a chamber containing wire gauze, so
as to prevent any explosion in the channel from reaching the regulator.
The first regulator in which the gas enters is disposed so as to stop
the engine when the inflammable gas ceases to flow in. It may be
objected to this arrangement that as the two pumps work simultaneously,
one taking in one part of lighting gas and the other two parts of atmo-
spheric air, for example, it may happen that the pump of the lighting
gas would work irregularly and only supply one-half or one-third of
the required amount while the air pump would furnish its larger quota;
in this case instead of one part of gas to two of air but one-half or
one-third part of gas would be obtained, and so an explosive mixture
might be supplied to the consumer; and as a remedy for the above
objection, supposing the motor employed to be a gas engine, it will not
be necessary in that case to employ a first regulator or receiver as
above-mentioned for stopping the engine when the gas from any cause
should cease to be supplied, as with a gas engine, when the gas ceases

page_text: to arrive it would evidently stop. This engine would be constantly
regulated by the motion of the outflow regulator, in order that it may
supply only just the amount of gas required for consumption. This
gas engine works only one gas pump but imparts increased pressure
to said gas; thus if a mixture of one part of gas and two parts of air
is to be supplied to the consumer at a pressure of six inches of water,
for example, the pump should supply the gas at triple that pressure
theoretically and practically at a much higher pressure in order to
compensate for the inevitable waste. The lighting gas thus escapes
from the pump at a pressure of more than twenty inches of water
iato an apparatus formed of two pumps working simultaneously; one
pump which supplies double the amount of the other at each stroke
is intended for taking in and compressing atmospheric air.
It will be understood that by employing known arrangements, such
as used in similar cases, the lighting gas entering the small pump at a
pressure of more than twenty inches of water alone suffices to work the
apparatus which would supply the two gases at a pressure of about six
inches. The mixture of the gases is then effected as before described
before passing to the regulator, the motion of the bell or receiver varying
according to whether a sufficient or insufficient supply of mixed gas
enters for consumption, and so regulating the motion of the gas engine.
It would be of advantage to place a sheet-iron reservoir between the
gas pump driven direct by the motor and the double pumps through
which reservoir the gas is caused to pass. The gas enters in a much
more regular manner into the double pump apparatus above-mentioned;
this may be composed either of two pumps working simultaneously,
one having double the capacity of the other, and the gas acting
successively on each side of the piston of the smaller one. Instead
of this double bell receivers may be employed immersed in water and
connected by a balance, the lighting gas entering successively into
the smallest compartment of the two double receivers while the air
is drawn into the larger one; or double rotating apparatus may be
used on the principle of an extractor, while one of these two arrange-
ments of double receivers receives lighting gas and takes in atmospheric
air, the other supplies the two gases which are then mixed as before
described.

page_text: consisting of two bellows cach enclosed in a separate case, the smaller
one for the gas and the other of double the size for the air, the
motion of both bellows being simultaneous. They may for example be
formed of a metal disc connected to one side of the case by flexible
membranes, said disc being regulated in its motion by a shaft passing
through the case in suitable stuffing boxes, the said bellows being
connected by the aid of the shafts. While the lighting gas enters
alternately on opposite sides of the small bellows, and by its elastic
force sets the two in motion, the air is forced to enter on both sides of
the larger bellows, first being drawn in and then compressed by the
reverse movement.
With a similar arrangement of parts it will be evident that the
volume of lighting gas can never be less than one part to two of atmo-
spheric air, and supposing the apparatus to fail from any cause it would
only tend to augment the volume of lighting gas, and consequently still
more lessen the danger of explosion.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Melville Clark in the Great Seal Patent
Office on the 31st July 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the First day of February, in the year
of our Lord One thousand eight hundred and sixty-eight, in the
thirty-first year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Alexander Melville Clark, Her
special licence that I, the said Alexander Melville Clark, my executors,
administrators, and assigns, or such others as I, the said Alexander
Melville Clark, 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 Inven-

page_text: tion for "IMPROVEMENTS IN THE MODE OF UTILIZING AND INCREASING THE
LIGHTING POWER OF GASES AND INFLAMMABLE VAPORS, AND IN APPARATUS
CONNECTED THEREWITH," a communication to me from abroad by Edouard
Armand d'Hurcourt, Civil Engineer, of 29, Boulevart St. Martin,
Paris, upon the condition (amongst others) that I, the said Alexander
Melville Clark, 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 Alexander Melville Clark, do
hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the Sheet
of Drawings hereunto annexed, and to the letters and figures marked
thereon (that is to say) :-
-
This Invention relates to the mode of mixing lighting gas and atmo-
spheric air in previously determined proportions, and of conveying said
mixture by means of suitable channels cither to burners of peculiar
construction for the purpose of obtaining light by raising an infusible
body, such as platina, to a white heat, or for obtaining heat in any
suitable apparatus. This mixture may be effected either at the gasworks
or by the consumer at the meter in each house. Instead of using
ordinary lighting gas a mixture of gases or inflammable vapors with pure
oxygen, deutoxide or protoxide of azote may be used. I am aware that
light has before been obtained by means of a mixture of lighting gas and
atmospheric air or oxygen effected in an apparatus itself provided with a
burner such as the Drummond lamp, but these gases have never hitherto
been mixed in an apparatus either at the manufactory or by the con-
sumer. The advantage of such an arrangement is that whether applied
for lighting or heating purposes a double set of pipes is not required.
The Invention further relates to the application of the platinum
burner known as the Gillard burner used for burning pure hydrogen
with the mixture above described. The mixture intended to furnish the
greatest amount of heat also gives the most light, which is incomparably
superior to that of the lighting gas contained in the mixture usually

page_text: employed by itself; it is thus unnecessary to manufacture what are
known as rich gases which are very costly since inflammable gases of all
kinds may be made to answer the same purpose. The proportion I find
most suitable for mixing with ordinary coal gas both as regards the
facility of lighting and the beauty of the flame are one part of gas to two
of air, although I do not limit myself to these proportions. As the most
perfectly constructed apparatus is liable more or less to get out of order
the gas may become explosive by increasing the proportion of atmospheric
air to seven or eight parts to one part gas. I employ an apparatus designed
to prevent such a case happening. I take two meters, one of double the
capacity of the other, mounted on the same axis so as to turn together.
I introduce the gas under pressure into the smaller chamber only, the
drum of which in turning carries with it the large chamber, the inlet
pipe being arranged to permit of atmospheric air entering therein. Each
revolution of the small meter supplies a proportion of lighting gas and
the larger one a double proportion of atmospheric air. The gases after
leaving the meter are conveyed by means of a pipe into a ball or sphere,
where they are mixed, and thence pass into the pipes. In this manner
the small chamber acts as the motor and the larger one as a blowing
apparatus set in motion thereby. Thus at each revolution the small
chamber supplies a volume of gas equal to its capacity, and even should
an escape take place the supply will never become deficient. As regards
the larger chamber which acts as a pump or blowing apparatus it will
mostly supply a volume of air at each revolution equal to its capacity,
but never more, and supposing an escape to take place it will necessarily
supply less, and sometimes none at all. The lighting gas being thus
alone supplied under pressure is rendered available for taking in a supply
of air, compressing and mixing it with the gas escaping, and as the
proportion of lighting gas in case of accident or escape will be increase
or that of the air diminished the risk of explosion is thus considerably
lessened, and supposing the burners to get out of order this will not
constitute a source of danger, while they may be readily repaired. A
manometric pressure of 2 or 3 inches of water is sufficient for a mixture
of one part lighting gas and two of atmospheric air, and will permit of
considerable economy being obtained in the consumption of gas, hence it
will be necessary to supply the gas at triple this pressure, say eight
inches for example, and considerably higher in practice considering the
friction. These pressures must be increased still more when it is desired

page_text: to convey the mixture long distances, in which case it will be necessary
to modify the construction of the ordinary meters by increasing their
diameters.
Other arrangements may also be adopted, for example, I take a pump
such as those used in steam engines, the piston of which would be acted
on alternately on opposite sides by the pressure of the gas entering.
The inlet and outlet of the gas would be regulated by a slide valve such
as are used in steam engines or in gas regulators with diaphragms, which
valve is operated by the to-and-fro motion of the piston. This pump
would serve to drive an ordinary blowing apparatus, the relative pro-
portions of each being previously determined so as to obtain a mixture
in the requisite quantities. The pistons and stuffing boxes would require
to be made perfectly gas-tight and at same time absorb as little friction
as possible; and it is preferable in lieu of stuffing boxes through which
the piston rod passes to use hydraulic joints similar to those employed
for the valves of gasworks, mercury being substituted for the water.
Instead of using a piston both in the gas engine and blowing apparatus
an iron bell chamber or receiver may be employed placed in a trough
containing mercury, the gas or air being supplied alternately above and
below; or the pumps may be replaced by two cylindrical vessels, such
as shown at A, B, Figure 1 of the Drawings annexed, united together
by flanges embracing a flexible membrane, to which is fixed a metal
disc m, n, acting as a piston and provided with a rod passing through a
stuffing box above.
Figure 2 shows a vertical section, Figure 3 a horizontal section,
Figure 4 an end view, and Figure 5 a plan of an apparatus in which
stuffing boxes are entirely dispensed with.
The apparatus consists of a cylinder a, a, b, b', provided with a central
partition m, m³, and connected by means of flanges to two cylindrical
chambers e, e, f,f', each of which contains a chamber K provided with
flanges, . On each side of the diaphragm m, m', there is a movable
cylindrical part 8, 1, 8', u', united to a circular disc t, t, provided with
flanges a, a, t, t', as also by r, r¹, u, u', so as to form closed com-
partments G, G, A, A'. Two movable parts u, u, l, t, placed at
each side of the diaphragm m, m', cach carry two arms x, x³, attached
at one end to the flanges u, u', passing through longitudinal slits made
in the cylinders a, a', e, e', b, b', f,f', and fixed at their opposite ends

page_text: to the upper tubes, y, z, y', which are fitted to move freely in a
longitudinal direction in guides o, o', fixed to the bottom of the cylin-
drical chambers e, e, f,f. In this manner the two chambers u, u', l, t,
on each side of the diaphragm m, m', are maintained at an invariable
distance apart, motion being transmitted from the one to the other
reciprocally. A valve box T is fixed at the top of the case a, a, b, b',
through which the gas enters above, and is caused by the action of the
valve to circulate either to the right or left in order to enter chamber
G or G. These valves act in the same manner as those of dry gas
meters, so that when the gas enters at the right, for example, into the
compartment G' it escapes at the left of chamber G, returning to the
valve box T and out at pipe S. The two compartments A, A', serve
alternately to draw in atmospheric air, and then expel it for the purpose
of mixing with the lighting gas escaping at S. For this purpose I
mount on the outside of case a, a, b, b', on each side of diaphragm
m, m³, two small cylindrical chambers Y, Y', provided at top and bottom
with leather valves opening upwards. Atmospheric air enters at the
lower valve, when the suction commences in one of the chambers and
passes out at the upper valve when expelled through pipe R to join
the gas escaping at S. The mixed gases pass off through pipe C. It
is unnecessary to describe the action of the valve, which is produced
by the to-and-fro motion of the two rods j, j', attached to the
flanges u, u, and passing through cylinders a, a', c, c¹, b, b¹, ƒ, ƒ'.
The following is the action of the apparatus:-The gas entering at
Gacts on the part t, l', u, u', and consequently on the other portion
of same on the opposite side of the diaphragm m, m³, the two being
connected by the tubes, y, ¹, y'. The air contained in chamber A'
is thus driven out, as also the lighting gas previously introduced into
chamber G, and the suction being produced in the chamber A atmo-
spheric air will be introduced. The valve on reaching the end of its
course becomes changed in position, the motion is reversed, and so on.
The relative sizes of the chambers A, G, are determined according to
the proportions of the gases or vapors forming the mixture. The
necessity of burning the gas, at a pressure of 2 or 3 inches of water
requires the lighting gas to be supplied at a greater pressure (equal
to eight inches), for which purpose it has to be compressed. The
pump to be used for compressing the gas should not (in case the
consumption were to cease, for example) exceed a certain limit of

page_text: pressure, such as to compromise the safety of the apparatus, and if
from any cause the gas should flow in insufficient quantity or cease
entirely it should be prevented from forming a vacuum. For this
purpose I propose to use the following arrangement of apparatus repre-
sented in vertical section at Figure 6, and in plan at Figure 7 of the
accompanying Drawings. It consists of two cylindrical chambers A, D,
placed in communication with cach other and covered the one with an
oiled leather membrane. The larger chamber A communicates with the
gas before it enters the compressing pump P; the membrane supports
a metal disc jointed at n, and provided with a hook taking on to the
horizontal rod a, b. If the pressure becomes reduced in consequence
of the insufficient supply of gas the disc falls, carrying with it the
rod a, b. This rod a, b, is mounted on an axis x, y, and is provided
at the forward end with a counterbalance P', whereby through the aid
of stem ta pressure is brought to bear on a valve & placed in chamber D,
closing the end of a pipe entering therein and communicating with
the gas from the compressing pump. If the pressure is too high it is
evident that the gas will raise the valve 8, and the weight P' enter
chamber D and pass from thence to chamber A to return to the pump,
and so on.
If an insufficient supply of gas should arrive the valve will
still open in consequence of the downward motion of the metal disc A,
thus the gas will be no longer compressed through the supply failing.
Having described the nature of the said Invention, and the manner
of performing the same, I declare that what I claim as the Invention
to be protected by the herein-before in part recited Letters Patent is,―
First. Mixing lighting gas and other inflammable gases and vapors
generally with atmospheric air, or other vapors or gases serving as aids
to combustion, either at the manufactory or by the consumer at the
meter, in the manner herein-before described, and whether to be used
for lighting or heating purposes.
Secondly. I claim the application of the Gillard platinum burner or
modification of the same, made of some infusible material, for burning
the mixed gases produced in the manner herein-before described.
Thirdly. I claim the mixing apparatus, arranged in the manner de-
scribed and as represented in the Drawings, designed to avoid all danger
of explosion.

page_text: Fourthly. I claim the apparatus represented in Figures 6 and 7 of the
Drawings to be adapted to a compressing pump to prevent the pro-
duction of too high pressure or the formation of a vacuum in case
of an insufficient supply of gas.
In witness whereof, 1, the said Alexander Melville Clark, have
hereunto set my hand and seal, this Thirty-first day of July,
in the year of our Lord One thousand cight hundred and sixty-
eight.