Gas Lamps Automaticany.
Year: 1885

page_text: Gas Lamps Automaticany.
0127
We JOSEPH JOHN BUTCHER of 4 St Nicholas' Buildings and JOHANN HEINRICH
WUSTER of C, Blandford Street both in the City and County of Newcastle' on
Tyne Engineers do hereby declare the nature of our invention for LIGHTING
AND EXTINGUISHING STREET AND OTHER GAS LAMPS AUTOMATICALLY to be as
follows:
Our apparatus consists essentially of two parts one of which is an automatic
valve for turning on the gas to the burner and the other of which is a means of
communicating light to the gas jet when it is turned on.
The automatic valve consists essentially of two divisions in one of which is
a surface or area (hereinafter called the lifting surface) which is constantly exposed
to the pressure of the gas and which is of such extent that when the gas has
attained a certain pressure (hereinafter termed the lighting pressure) the latter
lifts the valve and so turns on the gas to the burner and in the other of which is
a surface or area (hereinafter called the sustaining surface) which is of such extent
that it sustains the valve (in some cases with and in some cases without the
assistance of the lifting surface) in the open position while the pressure is being
substantially diminished.
From the lifting and sustaining surfaces of this valve are suspended certain
walls or partitions (the outer wall being preferably cylindrical in shape) together
with a tube the bottom of which forms the working edge of the valve. This
working edge may break the gaseous communication either by dipping in a liquid
(such as mercury) or by coming into contact with a solid and elastic substance
(such as a rubber ring). The walls or partitions must be so formed that while
they remain under all ordinary circumstances practically gas tight, they permit of
the rise and fall of the valve as a whole. This latter purpose may be effected
either by making thein dip deeply into and work constantly within mercury (or,
other suitable fluid) or by making them flexible. They may be made flexible
either by forming them of very thin metallic plate (say of copper) corrugated
annularly so as to permit of their extension and compression longitudinally under;
the influence of the gaseous pressure, or by uniting the rigid material forming
the lifting and sustaining surfaces to the casing by means of rings of a flexible

page_text: inaterial (such as rubber or leather) the inner edges of these rings being attached
to the moveable surfaces of the valve and the outer edges being attached to
the casing.
The lifting surface of the valve must be so arranged that when it is raised by
the pressure of the gas it carries the working edge of the valve and the sustaining
surface up with it, but in some cases the apparatus may be so arranged that after
lifting has taken place the sustaining surface together with the valve alone remain
lifted, the lifting surface with its partition walls then acting independently and
falling back into its normal position. In the latter case however these two parts
of the valve must be independently weighted-the sustaining surface inust be so
weighted that when' acting independently it will fall and close the valve when the
gas pressure has fallen to the pressure at which it is desired that extinguishing
should take place, while the lifting surface must be so weighted that when
bearing the burden of the sustaining surface its valve, partitions, wall, and weights,
it lifts and opens the valve when the pressure of the gas has risen to the lighting
pressure.
We will now proceed to describe in detail some of the forms which this automatic
valve may be made to assume in practice.
We will first describe the last mentioned form of apparatus assuming for con-
venience that the walls partitions and working edge of the valve all work in and
are sealed by mercury (although it will be obvious that these might be formed on
one of the other plans mentioned above, and subsequently described as forming
parts of other forms of air valve).
In this apparatus the complete valve is formed of two separate bells one of
which may be called the lifting bell and the other of which may be called the
sustaining bell. Each bell consists of an outer cylindrical and inner cylindrical or
oval wall, the lower edges of which work constantly within the mercury, a cover
plate uniting the top edges of these walls, and a cup placed upon the top of the
cover plate and used for the reception of weights for balancing the pressure.
The inner wall of the lifting bell is made sufficiently large to contain the valve
tube and the other pipes to be described.
The casing of the apparatus which we usually form of cast iron has a boss
formed on the under side which is screwed internally and attached to the gas pipe
in the lamp post. From immediately above the gas pipe a hole or channel is
formed in the metal of the casing which conveys the gas to within the lifting bell.
The outer wall of this bell may be cylindrical in form, and its lower edge dips in
mercury. The inner wall (the lower edge of which also dips in mercury) is of
such size and shape as to enclose the various gas pipes to be subsequently described.
A cover plate connects the outer wall with the inner wall but is not continued
within the inner wall through which an opening. is .left. Upon the top of the
coverplate a cup for weights is fixed.
The sustaining bell may be of larger area, its outer wall being just clear of the
outer wall of the lifting bell and dipping into the mercury in a similar manner.
The cover plate extends over the top of the weight cup of the lifting bell. In a
hole in the centre of this plate a tube is fixed, which is sufficiently large to admit
of the gas service pipe passing upwards through it. The lower edge of this tube
also dips into mercury and it forms the inner wall of the sustaining bell. Beside
this tube hangs a shorter tube attached. at the top to, and closed by the cover
plate.
The bottom edge of this tube is the working edge of the gas valve and dips into
mercury when the bell is not lifted, but rises out of the mercury when the bell is
lifted. The gas is supplied to this valve tube by a pipe within it which is fixed
into the casting at the bottom and communicates through a hole in the same with
the gas supply pipe. The gas delivery pipe is also fixed beside the inner tubular
wall of the sustaining bell and is bent at the bottom in the casting and has its
delivery end placed centrally with regard to the apparatus and also vertically.
This latter portion of the pipe passes upward through the inner tubular wall and

page_text: thereby forms a guide for the whole valve and also may be made to act as a bolt,
to hold down the cover which closes in the casting which contains the whole,
valve. On the top of the sustaining bell is a cup for weights through which the
inner tubular wall of the bell also rises.
The lifting surface may also be where convenient formed in rigid connection
with the sustaining surface-the former doing duty as part of the sustaining
surface when the valve is open (as described and illustrated in our patent
No 6386/ Under these circumstances it may sometimes be convenient to make
the outer surface the lifting surface and to place the valve and the tube which
supplies it with gas near the centre of the apparatus. The walls of the apparatus
may be made flexible so as to permit of its rising and falling by forming them of
thin copper or other plate corrugated circumferentially (like a Fox boiler tube,
but more deeply in proportion to the thickness of the plates). If a number of
corrugations are thus formed in a very thin cylinder of plate it will be elastic
longitudinally. The bottom of one of these corrugated partition walls is then
attached to the casing of the apparatus and the top to the plate forming the
sustaining or lifting surface.
.
Another way of rendering these areas gas tight while permitting of the rise and,
fall of the working surfaces without the use of a liquid sealing medium for the
partition walls is to connect the rigid plate forming the lifting or sustaining
surface with the inner edge of a ring of leather or rubber the outer edge of which
is attached so as to be gas tight to the metal casing of the apparatus. These
flexible rings should be properly formed so that they permit of the up and down
travel of the surfaces within the desired limits without the material being stretched
in the operation. This may be done in leather by means of pressing the ring into
a conical form by similar means to those employed in the preparation of the
U rings for packing hydraulic glands. The normal form of the leather being then
conical it will permit of the travel of the plate without any radial extension of the
leather taking place. The same form may be produced in rubber or other suitable
material out of. which it may be convenient to form these flexiblo rings.
In cases in which the working edge of the valve is made to close against some
elastic solid (instead of mercury) it is important that a sufficient pressure should
take place to ensure the valve being tight when closed. To secure this end we
may employ a tube of small circumference with a thin edge working against soft
rubber (or other suitable material), the pressure areas, of the valve being, made
relatively large so as to ensure a considerable pressure of the working edge against
its seat.
To enable the valve and its containing casing to be made of small size while
preserving the pipe connections of sufficiently large size we may make the partition
wall between the lifting and sustaining compartments of oval or flat sided or other
suitable form. In the case of an oval the pipe rising into the valve between this
wall and the outer wall is so placed as to stand between the least diameter of the
oval and the outer wall, and the pipe entering between the oval partition and the
guide tube is placed in the long axis of the oval and intermediate between the wall
of the guide tube and the end of the oval. The valve and pipes thus become very
compact.
We sometimes so arrange the apparatus that the small tube which supplies the
permanent flame is contained within the main service pipe which supplies the large
burner. This may be done in an apparatus in which this service pipe is cast into
the apparatus as a central guide tube in the following manner. A hole may be
drilled in a line with the centre of this pipe into the bottom of it from the recess
in the underside of the apparatus into which the gas first enters. Into this hole a
small brass (or other) pipe may be inserted from above (being passed down through
the iron service pipe) the small tube being of such size as not too greatly to
diminish the effective aperture of the service pipe) and screwed and rivetted or
otherwise securely fastened into its place so as to form a connection for the gas to
pass direct to the permanent flame from the gas main. The small tube is made to

page_text: project above the large tube and both are screwed outside with the same number
of threads to the inch and synchronously, A small brass or other casting is then
screwed on to these two pipes simultaneously. The small pipe then communicates
with a hole in the casting which leads to a horizontal passage which passage again
becomes vertical and leads to the burner of the small permanent flame.
The main gas burner is fixed above the service pipe and holes (drilled or other-
wise formed in the brass casting) permit the gas to pass the junction of the small
pipe with its horizontal gas passage. A suitable standard is arranged above these
holes for the reception of the ordinary gas burner. Around the vertical passage
leading to the permanent flame suitable brackets or holders are formed on to which
the guard for the protection of the flame from draughts may be fitted and from
which it can be, readily removed. These brackets are arranged with spaces between
which permit of the ventilation of the flame. The small flame ignites the main
gas jet through a little hole in the cover plate immediately above the flame which
is not large enough to carry away the waste products of combustion arising from
the flame The latter may be allowed to escape through an annular aperture in
the casing above the level of the flame or may (where great care to prevent
draughts from affecting the little flame requires to be used) be carried off through
two small chimneys rising from the sides of the cylindrical protecting casing and
flanking the limb of the main gas jet which projects over the igniting jet on either
hand: The igniting jet is so positioned that it is immediately below one limb of
the main gas jet and the bottom of the latter flows over and is in close proximity
to the cover plate of the protector.
111
...
In cases where small valves are used sealed with mercury we prefer to construct
them in the following manner. We construct each ring, oval partition, or tube,
out of very thin sheet iron with a longitudinal joint, formed by folding back the
edge of each plate in opposite directions then hooking, the edges together and
afterwards pressing or hammering the joint thus made firmly together. Where very
thin plate is used (such as the iron plate used for making tinned-plate) an almost
tight joint can be made in this way, but to secure the permanent tightness of the
joint we finish the construction of the valve by dipping the whole in lacquer or
enamel or otherwise Coat it with a substance which is unaffected by mercury,
avoiding the use of solder as far as practicable. Although these longitudinal ring
joints are the most liable to be affected by mercury it may be desirable to construct
the entire valve without using it. This may be effected in the following manner.
A cover plate may be stamped with lips to grasp the outer ring and a recess or
step on to which to fix the inner partition, and a central hole with a lip flange
may be also stamped on this plate to receive the guide tube. A small cup may be
then formed for weights with a sleeve to slip over the upper projecting edge of
this guide tube so that this cup may be lifted off the valve at any time. This
sleeve we prefer to make to project below the cup so as to form a distance pièce to
keep a space between the bottom of the cup and the cover of the valve. The rings
and tube may then be soldered to the cover plate or if this is not desired and a
good fit is produced so that the lips firmly hold, the rings iron on iron the whole
may be lacquered or enamelled and tightness of jointing thus permanently secured."
If a governor is used with this valve the milled nut may be placed between the
valve cover and the bottom of the cup.
Dated this miuntaanth

page_text: Improvements in Lighting and Extinguishing Street and other
Gas Lamps Automatically.
We JOSEPH JOHN BUTCHER of 4 St Nicholas' Buildings and JOHANN HEINRICH
WÜSTER late of 6 Blandford Street and now of 125 Sandyford Road both in the
City and County of Newcastle on Tyne Engineers do hereby declare the nature of
our invention for LIGHTING AND EXTINGUISHING STREET AND OTHER GAS LAMPS
AUTOMATICALLY and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
Our apparatus consists essentially of two parts one of which is an automatic
valve for turning on the gas to the burner and the other of which is a means of
communicating light to the gas jet when it is turned on.
The automatic valve consists essentially of two divisions in one of which is a
surface or area-(hereinafter called the lifting surface) which is constantly exposed
to the pressure of the gas and which is of such extent that when the gas has
attained a certain pressure (hereinafter termed the lighting pressure) the latter lifts
the valve and so turns on the gas to the burner and in the other of which is a
surface or area (hereinafter called the sustaining surface) which is of such extent
that it sustains the valve (in some cases with and in some cases without the
assistance of the lifting surface) in the open position while the pressure is being
substantially diminished.
From the lifting and sustaining surfaces of this valve are suspended certain walls
or partitions (the outer wall being preferably cylindrical in shape) together with a
tube the bottom of which forms the working edge of the valve. This working
edge may break the gaseous communication either by dipping in a liquid (such as
mercury) or by coming into contact with a solid and elastic substance (such as a
rubber ring). The walls or partitions must be so formed that while they remain
under all ordinary circumstances practically gas tight, they permit of the rise and
fall of the valve as a whole. This latter purpose may be effected either by making
them dip deeply into and work constantly within mercury (or other suitable fluid)
or by making them flexible. They may be made flexible either by forming them
of very thin metallic plate (say of copper) corrugated annularly so as to permit of
their extension and compression longitudinally under the influence of the gaseous
pressure, or by uniting the rigid material forming the lifting and sustaining
surfaces to the casing by means of rings of a flexible material (such as rubber or
leather) the inner edges of these rings being attached to the moveable surfaces of
the valve and the outer edges being attached to the casing.
The lifting surface of the valve must be so arranged that when it is raised by the
pressure of the gas it carries the working edge of the valve and the sustaining
surface up with it, but in some cases the apparatus may be so arranged that after
lifting has taken place the sustaining surface together with the valve alone remain
lifted, the lifting surface with its partition walls then acting independently and
falling back into its normal position. In the latter case however these two parts
of the valve must be independently weighted, the sustaining surface must be 'so
.. 1
1. J.

page_text: weighted that when acting independently it will fall and close the valve when the
gas pressure has fallen to the pressure at which it is desired that extinguishing
should take place, while the lifting surface must be so weighted that when bearing
the burden of the sustaining surface its valve, partitions, wall and weights, it
lifts and opens the valve when the pressure of the gas has risen to the lighting
pressure.
We will now proceed to describe in detail some of the forms which this automatic
valve may be made to assume in practice.
We will first describe the last mentioned form of apparatus assuming for
convenience that the walls partitions and working edge of the valve all work in
and are sealed by mercury (although it will be obvious that these might be
formed on one of the other plans mentioned above, and subsequently described as
forming parts of other forms of our valve.)
In this apparatus the complete valve is formed of two separate bells one of
which may be called the lifting bell and the other of which may be called the
sustaining bell. Each bell consists of an outer cylindrical and inner cylindrical or
oval wall, the lower edges of which work constantly within the mercury, a cover
plate uniting the top edges of these walls, and a cup placed upon the top of the
cover plate and used for the reception of weights for balancing the pressure. The
inner wall of the lifting bell is made sufficiently large to contain the valve tube
and the other pipes to be described.
The casing of the apparatus which we usually form of cast iron has a boss formed
on the under side which is screwed internally and attached to the gas pipe in the
lamp post. From immediately above the gas pipe a hole or channel is formed in
the metal of the casing which conveys the gas to within the lifting bell. The
outer wall of this bell may be cylindrical in form, and its lower edge dips in
mercury. The inner wall (the lower edge of which also dips in mercury) is of such
size and shape as to enclose the various gas pipes to be subsequently described.
A cover plate connects the outer wall with the inner wall but is not continued
within the inner wall through which an opening is left. Upon the top of the
coverplate a cup for weights is fixed.
The sustaining bell may be of larger area, its outer wall being just clear of the
outer wall of the lifting bell and dipping into the mercury in a similar manner.
The cover plate extends over the top of the weight cup of the lifting bell. In a
hole in the centre of this plate a tube is fixed, which is sufficiently large to admit
of the gas service pipe passing upwards through it. The lower edge of this tube
also dips into mercury and it forms the inner wall of the sustaining bell. Besides
this tube hangs a shorter tube attached at the top to, and closed by the cover
plate.
The bottom edge of this tube is the working edge of the gas valve and dips into
mercury when the bell is not lifted, but rises out of the mercury when the bell is
lifted. The gas is supplied to this valve tube by a pipe within it which is fixed
into the casting at the bottom and communicates through a hole in the same with
the gas supply pipe. The gas delivery pipe is also fixed beside the inner tubular
wall of the sustaining bell and is bent at the bottom in the casting and has its
delivery end placed centrally with regard to the apparatus and also vertically.
This latter portion of the pipe passes upward through the inner tubular wall and
thereby forms a guide for the whole valve and also may be made to act as a bolt
to hold down the cover which closes in the casting which contains the whole valve.
On the top of the sustaining bell is a cup for weights through which the inner
tubular wall of the bell also rises.
The lifting surface may also be where convenient formed in rigid connection
with the sustaining surface the former doing duty as part of the sustaining surface
when the valve is open (as described and illustrated in our patent No 6386/5).
Under these circumstances it may sometimes be convenient to make the outer
surface the lifting surface and to place the valve and the tube which supplies it
with gas near the centre of the apparatus. The walls of the apparatus may be

page_text: made flexible so as to permit of its rising and falling by forming them of thin
copper or other plate corrugated circumferentially (like a Fox boiler tube, but more
deeply in proportion to thickness of the plates). If a number of corrugations are
thus formed in a very thin cylinder of plate it will be elastic longitudinally. The
bottom of one of these corrugated partition walls is then attached to the casing of
the apparatus and the top to the plate forming the sustaining or lifting surface.
Another way of rendering these areas gas tight while permitting of the rise and
fall of the working surfaces without the use of a liquid sealing medium for the
partition walls is to connect the rigid plate forming the lifting or sustaining
surface with the inner edge of a ring of, leather or rubber the outer edge of which
is attached so as to be gas tight to the metal casing of the apparatus. These
flexible rings should be properly formed so that they permit of the up and down
travel of the surfaces within the desired limits without the material being stretched
in the operation. This may be done in leatlier by means of passing the ring into
à conical form, by similar means to those employed in the preparation of the
U rings for packing hydraulic glands. The normal form of the leather being then
conical it will permit of the travel of the plate without any radial extension of the
leather taking place.!
The same form may be produced in rubber or other suitable material out of
which it may be convenient to form these flexible rings.
In cases in which the working edge of the valve is made to close against some
elastic solid (instead of mercury) it is important that a sufficient pressure should
take place to insure the valve being tight when closed. To secure this end we
may employ a tube of small circumference with a thin edge working against soft
rubber (or other suitable material), the pressure areas of the valve being made
relatively large so as to ensure a considerable pressure of the working edge against
its seat.
To enable the valve and its containing casing to be made of small size while
preserving the pipe connections of sufficiently large size we may make the partition
wall between the lifting and sustaining compartments of oval or flat sided or other.
suitable form. In the case of an oval the pipe rising into the valve between this
wall and the outer wall is so placed as to stand between the least diameter of the
oyal and the outer wall, and the pipe entering between the oval partition and the
guide tube is placed in the long axis of the oval and intermediate between the
wall of the guide tube and the end of the oval. The valve and pipes thus become
very compact.
We sometimes so arrange the apparatus that the small tube which supplies the
permanent flame is contained within the main service pipe which supplies the
large burner. This may be done in an apparatus in which this service pipe is cast
into the apparatus as a central guide tube in the following manner.
A holé may
be drilled in a line with the centre of this pipe into the bottom of it from the
recess in the underside of the apparatus into which the gas first enters. Into, this
hole a small brass (or other) pipe may be inserted from above (being passed down
through the iron service pipe) the small tube being of such size as not too greatly
to diminish the effective aperture of the service pipe and screwed and rivetted or
otherwise securely fastened into its place so as to form a connection for the gas to
pass direct to the permanent flame from the gas main. The small tube is made to
project above the large tube and both are screwed outside with the same number
of threads to the inch and synchroniously-A small brass or other casting is then
screwed on to these two pipes simultaneously. The small pipe then communicates
with a hole in the casting which leads to a horizontal passage which passage again
becomes vertical and leads to the burner of the small permanent flame.
The main gas burner is fixed above the service pipe and holes (drilled or
otherwise formed, in the brass casting) permit the gas to pass the junction of the
small pipe with its horizontal gas passage. A suitable standard is arranged above
these holes for the reception of the ordinary gas burner Around the vertical
passage leading to the permanent flame suitable brackets or holders are formed on

page_text: to which the guard for the protection of the flame from draughts may be fitted
and from which it can be readily removed. These brackets are arranged with
spaces between which permit of the ventilation of the flame. The small flame
ignites the main gas jet through a little hole in the cover plate immediately above
the flame which is not large enough to carry away the waste products of combustion
arising from the flame. The latter may be allowed to escape through an annular
aperture in the casing above the level of the flame or may (where great care to
prevent draughts from affecting the little flame requires to be used) be carried off
through two small chimneys rising from the sides of the cylindrical protecting
casing and flanking the limb of the main gas jet which projects over the igniting
jet on either hand. The igniting jet is so partitioned that it is immediately below
one limb of the main gas jet and the bottom. of the latter flows over and is in close
proximity to the cover plate of the protector.
In cases where small valves are used sealed with mercury we prefer to construct
them in the following manner. We construct each ring, oval partition, or tube,
out of very thin sheet iron with a longitudinal joint formed by folding back, the
edge of each plate in opposite directions then hooking the edge together and
afterwards pressing or hammering the joint thus made firmly together. Where
very thin plate is used (such as the iron plate used for making tinned plate) an
almost tight joint can be made in this way, but to secure the permanent tightness
of the joint we finish the construction of the valve by dipping the whole in lacquer
or enamel or otherwise coat it with a substance which is unaffected by mercury,
avoiding the use of solder as far as practicable. Although these longitudinal ring
joints are the most liable to be affected by mercury it may be desirable to construct
the entire valve without using it. This may be effected in the following manner.
A cover plate may be stamped with lips to grasp the outer ring, and a recess or
step on which to fix the inner partition, and a central hole with a lip flange may
be also stamped on this plate to receive the guide tube. A small cup may be then
formed for weights with a sleeve to slip over the upper projecting edge of this
guide tube, so that this cup may be lifted off the valve at any time. This sleeve
we prefer to make to project below the cup so as to form a distance piece to keep
the space between the bottom of the cup and the cover of the valve. The rings
and tube may then be soldered to cover the plate or, if this is not desired and a
good fit is produced so that the lips firmly hold the rings iron on iron, the whole
may be lacquered or enamelled, and tightness of jointing thus permanently secured.
If a governor is used with this valve the milled nut may be placed between the
valve cover and the bottom of the cup..
Figures 1 and 2 are two sectional elevations, at right angles to one another, of
one form of our apparatus.
Figure 3 is a sectional plan through the main valve; figure 4 is a sectional plan
above the small burner; and figure 5 is a view upon the top of the same.
The gas enters at A and A¹, upon the top of which we usually place the governor
(illustrated in our patent N° 6386/85). B is an oval midwall dividing the lifting
from the sustaining compartments. The gas passes off through the pipe C in the
sustaining compartment, and finds its way to the burner through C¹ C C³.
The construction of the valve is shewn clearly in the drawing, the joints being
shewn at B1 and B2, and the mode of attaching the rings to the plates at B³
and B-B is the cup for weights, its inner tube B sliding into the sleeve tube of
the valve B'.-D is the mercury, arranged in the channels D¹ D² and D³. This
mercury seals the midwall B when the valve is in the position shewn in the
drawing, and also seals the outer wall, and inner sleeve tube of the valve
permanently, so that no gas can escape round them. The side light E is fed
through the passage E¹, by the vertical pipe E2, direct from the main. E' is
screwed into the casting at E³, and rivetted over as shewn. The junction piece F
is screwed internally, for both the small and the large pipes, to the same pitch, and
in such a manner that when it is screwing upon the small pipe the thread cut upon
the large pipe will enter into it.. The small permanent. Hame G ignites the main
1

page_text: jet H through the hole in the protecting casing G, and the chief part of the
products of combustion of this small flame pass off through the annular opening G².
J is a light brass (or other) covering tube, which acts as a distance. piece between
the junction piece F and the valve box cover K, so that the latter is held firmly in
its place.
.
Figure 6 is a sectional elevation through the valve box of another modification
of our apparatus, and figure 7 is a sectional plan of the same. The gas enters at A,
and is conducted to the lifting compartment of the valve through the passage A¹.
B is the outer wall, B¹ is the inner wall, and B' is the cup for weights, of the
lifting division of the valve (which is constructed separately from the sustaining
division, and, after the act of lifting is accomplished, works independently of it).
C is the outer wall, and C¹ the inner wall (or sleeve tube) and C³ the cup for
weights of the sustaining division of the valve, which in the position shewn, rests
upon the top of the lifting division. C is a pendent pipe covering the inlet
pipe As, and dipping into the mercury (shewn by horizontal lines) so as to seal it
in the position shewn. The pipe C³ performs a similar function to that performed
by the mid-wall B of the valve shewn in figures 1, 2 and 3. D is the outlet pipe
leading to the main burner, and E is the small pipe supplying the permanent
flame.
The action of the valve is as follows. The gas pressure rises within the lifting
division until it is powerful enough to raise the whole of the two divisions of the
valves with their weights. The lifting division then rises, carrying the sustaining
division with it, until the pendent tube C³ emerges from the mercury, when the
gas gets free access to the sustaining division of the valve through A and C³.
The gas pressure being now equalised outside and inside the lifting division B, the
latter falls back again into the position in which it is drawn. But the gas within C,
having a larger area to act upon and less weight to carry, is able to sustain this
part of the valve until the pressure has fallen to considerably below the lighting
pressure. When however the gas pressure has fallen until it will not sustain this
weight, C falls until C³ enters the mercury, when, the pressure within the sustaining
division being reduced suddenly to that of the atmosphere, C also falls down into
the position shewn in the drawing, and the light is extinguished.
This valve may be weighted in the following manner. C may be lifted by hand
and the flame lighted, the gas pressure being that at which extinguishing is desired
to take place. Weights may then be placed in C', until C falls, and the flame goes
out. Then, the gas being supplied to the valve at the pressure at which it is desired
that lighting should take place, weights may be added to the cup B' until the gas
will only just lift the combined weight of C and B.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is
(1) In an apparatus similar to that described herein the use of a gas pipe for
supplying the small burner with gas so arranged as to be enclosed within the pipe
which supplies the large burner with gas substantially as herein before described
and illustrated in the accompanying drawings.
(2) The use of a casting screwed simultaneously on to the internal and external
gas pipes and so arranged as to form a rigid connection between the main gas
burner and the permanent flame and to act as a holder on which to fix the protecting
casing for the latter substantially as hereinbefore described and illustrated in the
accompanying drawings.
(3) The construction of a valve for the purpose described of two separate bells
one of which constitutes the lifting bell and carries the other up with it when
lifting and the other of which constitutes the sustaining bell and remains lifted
after the lifting bell has fallen to its former position substantially as hereinbefore
described and illustrated in the accompanying drawings.

page_text: (4) The construction of the lifting bell and the sustaining bell of such a valve
approximately similar in area but differentially weighted so as to turn on and off
the gas to the main gas jet at the pressures at which it is desired to light and
extinguish the lamps substantially as herein before described and illustrated in the
accompanying drawings.
(5) The construction of the wall which divides the lifting from the sustaining
compartments of the valve of an apparatus similar to that described herein of such
a form as to leave large spaces for the gas pipes substantially as hereinbefore
described and illustrated in the accompanying drawings.
.1%
(6) The protection of a small flame used for igniting a larger one by means of
a casing through a small hole (insufficient for carrying away the waste products of
combustion) in which, "placed vertically above the flame ignition is effected, and
through other openings in which (arranged above the level of the flame, but not
vertically above it) the waste products of combustion are carried off, all substan-
tially as hereinbefore described and illustrated in the accompanying drawings.
..(7) The formation of the protecting casing for the constant flame of a gas
lighting apparatus with two little chimneys, placed on either side of the limb of the
main flame substantially as hereinbefore described and illustrated in the accom-
panying drawings."
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