IMPROVE- MENTS IN GAS LAMPS
Year: 1882

page_text: LETTERS PATENT to Francis Herbert Wenham of Warbeck Road Shepherds
Bush in the County of Middlesex Engineer for an Invention of "IMPROVE-
MENTS IN GAS LAMPS"
PROVISIONAL SPECIFICATION left by the said Francis Herbert Wenham
at the Office of the Commissioners of Patents on the 28th August 1882.
FRANCIS HERBERT WENHAM of Warbeck Road Shepherds Bush in the County of
Middlesex Engineer "IMPROVEMENTS IN GAS LAMPS "
The gas supply is conveyed downwards through a pipe to a ring burner: This
may be of various forms but I prefer an annulus known as the "Argand" burner
inverted. The gas pipe descends through a chimney in the lower end of which is
attached an inner cylinder or chamber closed at the top through which the gas
pipe passes; outer air is admitted by side passages or tubes let through the
chimney into the inner cylinder which projects into the lamp glass and is
tapered to a nozzle the opening in which somewhat exceeds the Argand or ring
burner which it encloses. Attached to the base of the chimney is a flange or plate
which serves as a cover for the glass of the lamp. This may be in one piece either
cylindrical globular or made up of several panes of glass which should be framed
together practically air tight as all air necessary for combustion arrives from the top
plate. Within the lamp is a truncated dome or trumpet mouth for directing the
products of combustion into the chimney. To ignite the gas at the burner the glass
of the lamp may be removed or swung back on a hinge at the plate or a light may
be passed up through a small trap door at the bottom of a globe bell or cylinder
form of glass or if this is framed as a lantern by opening a side door when closed
in the hot air from the flame ascends the chimney through the space around the
inner chamber at the same time air required for combustion descends from the side
passages through the inner chamber wherein it becomes heated. The draft from the
chimney causes the heated air to be drawn down with considerable velocity and is
directed by the nozzle on to the flame. The hot products of combustion rising
outside the flame by preserving the heat add to the brilliancy of the light.

page_text: Around the air passages is a casing closed at the top but open below. The
outer air first rising through this economises heat and the entrances of the passages
are shielded from gusts of wind that might cause the light to be unsteady.
To obtain a flat or curved form of flame spread out laterally the downward
descent is prevented by a disc of metal or what as an application to an Argand
burner is known as a "button." This is attached as usual at a short distance by
a stem through the ring of the burner also the end of the inner hot air chamber
where it surrounds the burner is made wide or bell mouthed and the space between
the periphery of the burner and nozzle is covered with an annulus of wire gauze or
metal or clay ware either flat or preferably of a dished form or slightly coned
outwards. This plate is perforated with numerous small holes which distribute
the air supply over a large surface of flame and in order still further to extend the
flame the end is surrounded by a flange or ring. The orifice through the burner
should also be covered with gauze or a perforated plate for moderating the down-
ward velocity of the central current. By these combined means an upper and
lower or two separate currents of hot air are directed horizontally away or nearly
so from the axis of the lamp carrying a continuous and unbroken disc or sheet of
flame between them extending over the wide end of the nozzle In order to favour
this result in some cases the gas orifices may be round the periphery of the ring
burner or even be directed upwards.
Other lamps are arranged as follows; the ring burner is enclosed in a box or
casing which serves as a heating chamber from the cap of which rise a series of
elbow pipes or air channels passing through the top plate of the lamp having a
perforated wind guard over them. In the centre of this plate is an opening over
which a chimney is placed. When the gas is lighted the flame is carried outwards
and the hot air rises between the elbow pipe and over the top of the heating box
into the chimney above. The lamp glass being attached and fitting close to the
top plate the draught causes external air to enter by the elbow pipes into the box
and is thus heated before supplying the flame. By this arrangement the heater is
situated entirely within the glass chamber of the lamp and is detached and
independent of the chimney which may be loose and removeable. In external
appearance this lamp resembles the pendant globe lamp now in common use.
The arrangement for a pedestal lamp differs in detail. The glass globe for this
form has openings both at the top and bottom. As it is desirable to have these
openings as small as possible the glass rests below upon a plate or collar round the
standard. Through this rises the gas supply which finally passes up a short piece
of pipe through the centre of the burner and is screwed into the top cross channel
thereof. Instead of elbow pipes turning up through a top plate or flange this is
dispensed with and the air pipes are carried out sideways with the ends let through
a collar upon the upper edge of which the chimney base rests the opening of the
glass fits close round this collar which passes through it. The short piece of gas
pipe from the burner enters easily into a socket in the standard pipe, and is made
gas tight by a conical fitting. The collar with heating chamber and burner may
therefore be lifted off and the glass removed but if the lower opening in the glass
globe is a little wider than the upper one and rests upon a larger plate on the
standard the glass may be lifted off over the collar without removing this or its
attachments.
In lamps where the glass chamber or lantern is of large diameter either of
square hexagon or other shapes the series of air pipes radiating from the casing of
the central heating chamber are carried out through the metal rim or collar just
above the lower glass work of the lamp which must be framed together and the
door closed sufficiently air tight to cause all the supply to be drawn through the
radiating pipes to the heating chamber and to concentrate heat upon this and also
to serve as a reflector an open topped dome white enamelled is supported by the
radiating air pipes. In these arrangements the heating box being entirely isolated
from the chimney or its base and within the chamber of the lantern facilities are
given for a variety of constructions and shorter and smaller chimneys may be used

page_text: than in the form first described and the length of the pipes to the framework of
the lantern allows them to be bent more or less downwards or arched upwards as
the circumstances of the design may require.
For outdoor lamps constructed on these principles the inner air tight glass may
be enclosed within an outer one or lantern as a protection against fracture by wet
or cold the outer case having ventilating air holes above and below.
The ring end of the burner perforated with the gas orifices may be of metal but
I prefer porcelain or stone ware. In either case this end is made so as to be
detached with facility for the purpose of cleaning out any carbonaceous deposit
that may in time collect therein. This removeable end is drawn up in metallic
contact with the upper portion of the burner by means of what is known as a
bayonet, catch, or cam joint or other equivalent fastening a partial turn of which
releases the perforated ring.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Francis Herbert Wenham in the Great Seal Patent Office on
the 28th February 1883.
FRANCIS HERBERT WENHAM of Warbeck Road Shepherd's Bush in the County of
Middlesex Engineer "IMPROVEMENTS IN GAS LAMPS"
My Improvements in Gas lamps have for their object to increase the illuminating
power and greatly economise the consumption of gas as or when burned in the
said lamps. I will describe my Invention with reference to the accompanying
drawings wherein like letters of reference are used to indicate the same parts in
the different views of each form or modification of my Invention.
Figure 1 is a longitudinal Section Figure 2 a transverse Section on the line 1. 2
Figure 1 and Figure 3 is a transverse section on the line 3. 4 Figure 1 of a burner
constructed or arranged according to my Invention for giving what may be termed
a flat or curved form or unbroken sheet of flame spread out laterally as hereinafter
described.
The gas supply is conveyed downwards through a pipe a and branches or legs a
to a ring burner b. This burner b may be of various forms but I prefer an
annulus resembling the burner known as the "Argand" burner inverted. Tho
said gas pipe a descends through a chimney c in the lower end of which chimney
is situated an inner chamber d closed at the top through which also the gas pipe a
passes. Outer air to supply the flame is admitted by side passages or holes e cub
through the chimney and the inner chamber d. The lower end of the said
chamber & projects downwards as shewn and has formed on or affixed thereto a
bell mouthed bulbous or conical nozzle or termination k somewhat exceeding in
the diameter of its opening that of the argand or ring burner b which it encircles
or surrounds. Attached to the lower end of the chimney c is a flange or plate f
which serves as a cover for the glass g of the lamp. This glass may be in one

page_text: piece either cylindrical globular or made up of several panes of glass which should
be framed together approximately tight as all or nearly all air necessary for
combustion is supplied through the holes e Within the lamp glass is a truncated
cone or dome or trumpet mouth h which may be affixed to the plate f and is for
directing the products of combustion into the chimney c Around the chimney c
is a casing or guard closed at the top but open below-The outer air becomes
heated whilst rising through the passage formed by this casing j and the chimney
and also the openings e are shielded by the said casing from currents of air that
might cause the light to be unsteady. It will be evident that the casing ; may if
desired be only situated at the parts of the chimney at which the openings e
occur in place of being a continuous annular casing as shewn. The downward
descent of the inner current of air is prevented by a disc or button n of metal clay
or other incombustible substance-The space between the nozzle k and the periphery
of the burner b is covered with an annulus of wire gauze or metal or clay-ware
or other incombustible substance perforated with numerous small holes or openings
and either flat or preferably of a dished form or slightly coned outwards as shewn-
This annulus is for the purpose of distributing the air supply over a large surface
of flame and may be carried by a ring piece attached to the bell mouth k In order
still further to extend the flame the bell mouth k may be surrounded by a flange
or ring o which may form part of the ring carrying the gauze or perforated
annulus -The orifice through the burner should also be covered with gauze or a
perforated or divided plate or plates m² or equivalent means for moderating the
downward velocity of the central current. By these combined means an upper
and lower or two separate currents of hot air are directed horizontally or nearly
so out from the axis of the lamp carrying a continuous and unbroken disc or sheet
of flame between them extending over the bell mouth and ring o (if this latter
be used).
As will be seen by Figure 2 the inner chamber d divides the lower part of the
chimney into two parts or passages the strips m keeping the said chamber d in
place and serving also as heat collectors.
To ignite the gas at the burner the glass of the lamp may be removed or swung
back on a hinge g² attaching its frame to the plate there being also provided a
latch g³ or other fastening to secure it in position. Or a light may be passed up
through a trap door at the bottom of the glass or if it be framed as a lantern by
opening a side door. When the glass is closed the hot air from the flame passes
to the chimney c through the spaces at the sides of the inner chamber d. At the
same time the air required for combustion is drawn up between the guard ; and the
outside of the chimney and then passes by the side passages or apertures. e into and
through the inner chamber & becoming heated in its passage and being drawn
down with considerable velocity and directed by the nozzle on to the flame so
that the said flame burns between two currents of heated air directed outwards
from the ring burner by the gauze or perforated or divided plate l and button n
The gauze or perforated or divided plate m³ in the interior of the burner equalizing
or moderating the internal air current-The hot products of combustion rising
outside the flame and passing up through the spaces formed by the strips m and
the walls of the chamber d preserve the heat and add to the brilliancy of
the light.
Modifications of lamps with burners constructed according to my Invention
are shewn in Sheet 2 of the accompanying drawings. In the arrangement shewn
at figure 4 the ring burner bis enclosed in a box or casing c which serves as a
heating chamber from the top of which rise a series of elbow pipes or air channels &
passing through the top plate e of the lamp having a perforated wind guard fover
them outside the glass and the curtain around them inside the glass. In the
centre of the plate e is an opening over which a chimney g is placed. When the
gas is lighted the flame is carried outwards and the hot air rises between the elbow
pipes d and over the top of the heating box c into the chimney g above. The lamp
glass h being attached and fitted to the top plate e the draught causes external air

page_text: to enter by the elbow pipes d into the box or chamber c which air is thus heated
before supplying the flame. By this arrangement the heater is situated entirely
within the glass chamber of the lamp and is separated from and independent of the
chimney which may be loose and removeable.
The arrangement for a pedestal lamp shewn in section by figure 5 differs in detail
only from the last described arrangement. The glass globe a for this form has
openings both at the top and bottom which lower opening it is desirable should
be as small as possible to prevent shadow. The glass a rests below upon a
plate or collar b round the standard c. Through this standard rises the gas supply
which finally passes up a short piece of pipe d through the centre of the burner e and
is fastened to the top cross channel thereof by which the gas passes to the burner
proper. The upper portion or neck of the heating chamber passes through a plate
surrounded by a collar g. The products of combustion rise into the chimney through
a circle of tubes h terminating in the top plate i from which the burner is attached
by a pillar j. The dotted lines k through this pillar represent a gas passage which
would be provided for the connection of a gas pipe if this form were arranged for
use as a pendent lamp The air for supporting combustion enters at the wind
guard (which may be perforated) at the base of the chimney then passes between
the tubes h and by the neck through the heating chamber f to the flame. The
opening of the glass a fits round the collar ġ which passes through it. The short
piece of gas pipe d from the burner enters into a socket in the standard pipe
and may be made gas tight by a conical fitting m The collar with the heating
chamber and burner may therefore be lifted off and the glass removed but if the
lower opening in the glass globe be a little wider than the upper one and rest upon
a larger plate on the standard the glass may be lifted off over the collar without
removing this or its attachments.
b
In lamps where the glass chamber or lantern a is of large size as shewn by side
view and plan in figures 6 and 7 and made either of square hexagon or other shapes
the series of air pipes 6 radiating from the casing of the central heating chamber care
carried out through the metal rim or collar d just above the lower glass work of the
lamp which is framed together and the door closed sufficiently tight to cause the
main air supply to be drawn through the radiating pipes b to the heating chamber c
to which may be attached external fins or plates e to act as collectors and conductors
of heat thereto the external openings of the pipes b may be protected by. a wind
guard d². Gas is conveyed to the burner by the side pipes g provided with a stop
cock. h is a trap door for the entrance of the lighter. To concentrate heat upon
the chamber c and collect and direct the heated products into the chimney and also
if desired to serve as a reflector an open top dome or collector f (which may be
white enamelled) is supported by the radiating air pipes b. In these arrangements
the heating box or chamber c being entirely isolated from the chimney or its base
and within the chamber of the lantern facilities are given for a variety of construc-
tions and shorter and smaller chimneys may be used than in the forms first described
and the length of the pipes b to the framework of the lantern allows them to
be bent more or less downwards or arched upwards as the circumstances of the
design may require.
It will be understood that the wire gauze or perforated or divided plates for
distributing and controlling the supply of heated air to the flame and also the
button beneath the burners are in all the described modifications arranged in a
manner similar to that described with regard to the arrangement shewn in
Figure 1. In Figure 5 the button is shewn as being formed on the short pipe d―
The perforations in the ring or argand burner may be at the side, as in Figure 5,
or at the bottom, as in the other Figures: I prefer the latter.
For outdoor lamps constructed on these principles the inner glass may be
enclosed within, or protected by, an outer glass or protector enclosing it in whole or
in part as a protection against fracture by wet or cold or otherwise. Where this
protector takes the form of a complete outer case it may have ventilating air holes
above and below

page_text: The ring end a of the burner b (shewn separately by figures 8 and 9 perforated
with the gas Orifices may be of metal porcelain stoneware or other incombustible
substance. In either case this end may be made so as to be detached with facility
for the purpose of cleaning out any carbonaceous deposit that may in time collect
therein This removeable end a is drawn up into contact with the upper portion
of the burner b and fastened thereto by suitable means such for example as what is
known as a bayonet catch or cam joint c or other equivalent fastening which allows
of the ready release of the perforated ring a when required.
In order to prevent dirt clogging the orifices of the burner a wire or other
strainer may be placed in the gas channel above the orifices as indicated at x in
Figure 8.
In some cases such for example as when burning a highly carburetted gas it may
be advisable to admit a small amount of external air into the lamp casing in
addition to that heated and supplied as hereinbefore described.
Having now described the nature of my Invention and the manner in which the
same may be practically carried into effect I wish it to be understood that I am
aware that gas burners and lamps have been designed and made wherein the
intensity of the flame has been increased by heating either the air or gas necessary
for combustion or both of them by means of heating passages or surfaces situated
within above or below the flame and therefore I lay no claim thereto generally but
what I consider to be novel and original and therefore claim as the Invention
secured to me by the hereinbefore in part recited Letters Patent is―
First-The combinations and arrangements of parts forming the new and improved
gas lamps substantially as and for the purposes herein-before described and shewn
in the drawings hereunto annexed.
Secondly The new and improved arrangement of Gas lamp wherein are
employed a ring, Argand, or equivalent, burner, situated at the lower end of an air
heating chamber, and a disc or button beneath the burner; the space between this
chamber and the burner and also the central Orifice in the said burner being
covered with gauze or divided or perforated plates substantially as and for the
purposes hereinbefore described with reference to the accompanying drawings.
In witness whereof I the said Francis Herbert Wenham have to this my
Specification set my hand and seal this twenty eighth day of February
One thousand eight hundred and eighty three
FRANCIS HERBERT WENHAM (L.S.)