IMPROVEMENTS IN LAMPS
Year: 1878

page_text: For August 1000.
In the Matter of a Patent granted to JOHN THOMAS COOPER THOMAS, of
54, 55, and 56, Minories, in the County of Middlesex, Assistant to
Messieurs Ridsdale and Company, Lamp Manufacturers, for the Invention
of IMPROVEMENTS IN LAMPS, bearing date the Nineteenth day of
February, One thousand eight hundred and seventy eight, No. 688.
DISCLAIMER proposed to be entered by the said John Thomas Cooper Thomas,
as such Patentee as aforesaid pursuant to the Statutes in that case made and
provided.
WHEREAS I have been advised that certain claims made in the Specification
No. 088, A.D. 1878,
A
of the said Letters Patent, and which claims are numbered respectively 1 and 5,
are of doubtful validity: And whereas I wish to avoid objections which may be
made to those claims; I therefore for these reasons desire to disclaim, and I do
hereby disclaim from the Specification by striking out on page 4, lines 34 to 51
inclusive, of the Specification as it is printed by Her Majesty's Printers the words,
"Figs. 8 and 9 shew respectively in vertical section and in horizontal section
"another modification of my Invention. In this arrangement on a lamp body 6 of
"suitable shape I place a top 15, such as referred to in the Specification of the
"Patent hereinbefore mentioned, and below this top I form holes 9 in the sides of
"the lamp for the admission of air, protecting them by a wind-guard 10, or more
"than one wind-guard may be used. Immediately below I fix a metal plate 16 of
" the size of the interior of the lamp body; this I call a top plate, and it forms
a double top. In the centre of the top plate I insert a metal chimney 5,
"which extends upwards towards the top 15 of the lamp, and downwards
"towards the flame according to requirement. From above the top plate air
passages 6x extend downwards in to the double bottom of the lamp. Three
"closed sides 17 of the lamp form three sides of a box or chamber, of which the
" oil reservoir 7 and ledges 18 supporting it form the top and the lamp bottom the
"lower part. On the fourth or door side 19 is a piece of metal which fills the
opening left and renders the chamber air-tight when the door is closed. The
" only orifices in this chamber are those occupied by the burner and air passags.
"Air entering the holes 9 in the sides of the lamp passes down the air passages 6*
"
"

page_text: ff
"
"
"
" into the bottom chamber, and thence through the burner 4 and up the chimney 5 ;"
also by inserting after the word "that" on page 5, line 27, the words "no general
"claim is made to enclosing the flame in a chamber closed to the external atmo-
sphere except at and above the burner, and causing the air for supporting combustion
entering at the upper part of the lamp to pass downward and to enter the flame
chamber through the slot or burner, and the products of combustion to escape
through the upper opening in the flame chamber by a metal chimney, nor do I
"claim the construction of lamp shown in Figs. 8 and 9 of the Drawings, but ;
also by striking out the first claiming clause on page 5, lines 30 to 35 inclusive,
videlicet: "1. Enclosing the flame in a chamber closed to the external atmosphere,
except at and above the burner, and causing the air for supporting combustion
entering at the upper part of the lamp to pass downward and to enter the flame
"chamber through the slot or burner, and the products of combustion to escape
through the upper opening in the flame chamber by a metal chimney, all sub-
stantially as described;" also by substituting "1" for "2" at the commencement
of line 36, page 5; also by substituting "2" for "3" at the commencement of line
38, page 5; also by substituting "3" for "4" at the commencement of line 39,
page 5 also by striking out on page 5, lines 41 and 42, the fifth claiming clause,
videlicet, the words "5. The construction of lamp shewn in and described with
" reference to Figs. 8 and 9 of the Drawings; " also by substituting "4" for "6"
at the commencement of line 43, page 5; also by substituting "5" for "7"
at the commencement of line 45, page 5.
«
"6
*
"
And in order that the effect of this Disclaimer may be better understood I annex
a copy of the Specification as it will appear when such Disclaimer has been made
as aforesaid.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Thomas Cooper Thomas in the Great Seal Patent Office on the
16th August 1878.
JOHN THOMAS COOPER THOMAS, of 54, 55, and 56, Minories, in the County of
Middlesex, Assistant to Messieurs Ridsdale and Company, Lamp Manufacturers.
* IMPROVEMENTS IN LAMPS."
My Invention relates more especially to lamps exposed to wind or draughts, and
wherein glass chimneys are objectionable, as in railway, ships' signal, and other
lamps.
In my improved lamps the flame is in a suitable glazed chamber (bereinafter
called the flame chamber), closed to the external atmosphere except at and above
the burner; the air necessary to support combustion is admitted at the upper part
of the lamp, passes downward, and enters the flame chamber through the burner or
slot, and the products of combustion escape by a metal chimney above.
In order that my Invention may be clearly understood I will now describe, with
reference to the accompanying Drawings, the manner of carrying it into practical
effect.
Fig. 1 is a vertical section, Fig. 2 a horizontal section in the line A, B, of Fig. 1,
and Fig. 3 a part side view of a lamp according to my Invention. In this arrange-
ment the flame chamber 1 has in vertical section in one direction the form of two
frustrums of cones joined at their smallest diameters 2, and fitted into the lamp with
their axes horizontal, and their bases against opposite sides of the lamp. In front
of each base is glass 3, which is shewn as being plain, but may be in the form of a
lens, moveable or otherwise. The interior of the chamber I thus formed may be
reflective.
In the narrow part 2 of the chamber at the under side is a hole large enough to
admit a burner 4; above it is a hole for the chimney 5.
The lamp case 6 beneath the above described chamber 1 is made air-tight, and
contains or supports an oil reservoir 7 and wick holder 8, which can be got at by
opening or removing that part of the lamp containing the flame chamber 1. Above
this chamber (1) are holes 9 in the lamp case 6 to admit air, such holes being

page_text: protected by a wind guard 10, or more than one wind guard may be used if
required.
The top or head of the lamp is shewn as being similar to that described in the
Specification of Davis and Thomas' Patent of 28 April 1876, No. 1795.
The air entering by the holes 9 in the upper part of the lamp passes down outside
the flame chamber 1 to the flame at 11, and after combustion passes up the chimney 5,
and out at the top.
Fig. 4 shews a modification of flame chamber suitable for use in cases where the
light is required to shew in one direction only. The flame chamber 1 in this
arrangement has the form of one cone closed at its small end 2, its base being
arranged to lie against one side of the lamp, and orifices being formed in its under
and upper parts to admit respectively the burner 4 and the chimney 5.
Figs. 5, 6, and 7 shew respectively in vertical section, in horizontal section, in
the line C, D, of Fig. 5, and in horizontal section in the line E, F, of Fig. 5,
another modification of my Invention. In this arrangement two frustrums of
cones (which I will call cones 12, 13), not joined together as before described, are
arranged vertically. The base of the one cone 13 is on a flange 14, or it may be
on the bottom of the lamp; the other cone (12) is inverted, and suitably fixed in
the upper part of the lamp, as shewn.
A space
2 is left between the small ends of
the upper and lower cones. In the opening of the small end of the lower cone 13
is placed a burner 4, and enclosed in the lower cone 13 is an oil tank 7. In the
opening in the smaller end of the upper cone 12 is placed the chimney 5.
The head of the lamp is similar to that used in the lamps last described, but the
air for feeding the flame is brought from the upper to the lower part of the lamp
by means of tubes or channels 6* whose open tops are above the level of the top
or highest part of the upper cone 12, and their open bottoms enter the bottom
chamber beneath the base of the lower cone 13. A glass annulus 3 (or it may be a
lens) surrounds the two cones 12 and 13, so that air shall be excluded except so far
as entering at the top (through the holes 9); it can make its way down the air
tubes 6×, and thence through the burner 4 and up the chimney 5. In the Drawing
four air tubes or channels 6* are shewn, but the number may be varied to suit
circumstances.
Figs. 10, 11, and 12 shew another modification of my Invention, Fig. 10 being a
vertical section of the lamp; Fig. 11, a plan shewing the interior of the glass bowl,
hereinafter mentioned, and Fig. 12 a plan of the reflector. In this arrangement, in
constructing the flame chamber 1, I use a lamp bowl 1* cast with air passages 6*
extending from the top edge of the bowl to a glass or metal chamber 20 in the
bottom of the bowl; in this chamber 20 I place a metal tube 21 of less depth than
the chamber 20, and perforated in parts not directly exposed to the air passages;
or the two air passages may be joined beneath the burner by means of a horizontal
perforated metal or other tube. A reflector 22, of the shape shewn or other suitable
shape, is fitted close to the top of the bowl 1*; a metal chimney 5 is fitted into
this reflector. Above is arranged an oil tank in the space 7; the tubes 23 leading
from it pass through the reflector and down to the burner 4. 4* is the moveable
wick holder; around the outside of the burner 4 is tube 24 which, when the lamp
is dropped into its place, fits close round the glass chamber in the bowl above
referred to; over the wick holder or burner is a cone 25 which fits closely to the
tube encircling the burner.
The arrangement just described may be modified, as shewn in Figs. 13 and 14,
where metal air arms 6* are used opening above the reflector 22, and passing
through it, the air conveyed through them being discharged into a small cylindrical
air-tight chamber 20, whose bottom is closed by the glass of the bowl.
To guard against the effects of overflow I may slightly curve the bottom of the
bowl upwards, and cut slots in the air-tight chamber 20 to allow the oil, which
may accidentally overflow, to run away clear of the burner. By this arrangement
I also get a small supply of air through to the bowl, which helps to cool the heated
air contained therein.

page_text: The air arms are made so as to be moveable; after passing through the reflector
they enter a corresponding piece of tube 26 fixed to the reflector, and are there
secured by a suitable fastening.
In the upper portion of the lamp are holes 9 for the admission of air. The only
way by which the flame can be fed with air is therefore by its passage down the
air passages or tubes 6* referred to above.
Having described the nature of my said Invention, and explained the manner of
carrying it into practical effect, I hereby declare that no general claim is made to
enclosing the flame in a chamber closed to the external atmosphere, except at and
above the burner, and causing the air for supporting combustion entering at the
upper part of the lamp to pass downward, and to enter the flame chamber through
the slot or burner, and the products of combustion to escape through the upper
opening in the flame chamber by a metal chimney, nor do I claim the construction
of lamp shewn in Figs. 8 and 9 of the Drawings, but what I consider to be novel
and original, and therefore claim as secured to me under the Letters Patent
hereinbefore in part recited is,-
1. The construction of lamp shewn in and described with reference to Figs. 1, 2,
and 3 of the accompanying Drawings.
2. The arrangement described with reference to Fig. 4 of the Drawings.
3. The construction of lamp shewn in and described with reference to Figs. 5, 6,
and 7 of the Drawings.
4. The construction of lamp shewn in and described with reference to Figs. 10, 11,
and 12 of the Drawings.
5. The construction of lamp shewn in and described with reference to Figs. 13
and 14 of the Drawings.
In witness whereof, I, the said John Thomas Cooper Thomas, have hereunto
set my hand and seal, this Seventeenth day of July, in the year of our Lord
One thousand eight hundred and eighty.
To the Commissioners of Patents for Inventions.
Thomas
I hereby grant my fiat giving leave to the above named John Cooper Thomas
Offlce,
A
to file in the Great Seal Patent with the Specification to which the same relates,
the above written Disclaimer and Memorandum of Alteration.
Dated this 25th day of August, 1880.
FARRAR HERSCHELL,
Solicitor General.

page_text: LETTERS PATENT to John Thomas Cooper Thomas, of 54, 55, and 56, Minories,
in the County of Middlesex, Assistant to Messieurs Ridsdale and Company,
Lamp Manufacturers, for the Invention of "IMPROVEMENTS IN LAMPS."
ealed the 16th April 1878, and dated the 19th February 1878.
PROVISIONAL SPECIFICATION left by the said John Thomas Cooper Thomas
at the Office of the Commissioners of Patents on the 19th February 1878.
JOHN THOMAS COOPER THOMAS, of 54, 55, and 56, Minories, in the County of
Middlesex, Assistant to Messieurs Ridsdale and Company, Lamp Manufacturers.
"IMPROVEMENTS IN LAMPS."
My Invention relates more especially to lamps exposed to wind or draughts, and
wherein glass chimneys are objectionable, as in railway, ships' signals, and other
lamps.
In my improved lamps the flame is in a suitable glazed chamber (herein-after
called the flame chamber) closed to the external atmosphere except at and above
the burner. The air necessary to support combustion is admitted at the upper
part of the lamp, passes downward, and enters the flame chamber through the
burner or slot, and the products of combustion escape by a metal chimney above.
In one arrangement the flame chamber has in vertical section in one direction
the form of two frustums of cones joined at their smallest diameters and fitted into
the lamp with their axes horizontal and their bases against opposite sides of the
lamp. In front of each base is glass, either plain or in the form of a lens, moveable
or otherwise. The interior of the chamber thus formed may be reflective.
In the narrow part of the chamber at the under side is a hole large enough to
admit a burner; above it is a hole for the chimney.
The lamp case beneath the above-described chamber is made air-tight, and con-
tains or supports an oil reservoir and wick holder, which can be got at by opening
or removing that part of the lamp containing the flame chamber. Above this
chamber are holes in the lamp case to admit air, such holes being protected by a
wind guard or guards.

page_text: The top or head of the lamp may be similar to that described in the Specification
of Davis and Thomas' Patent of 28th April 1876, No. 1795.
The air entering by the holes in the upper part of the lamp passes down outside
the flame chamber to the flame, and after combustion passes up the chimney and
out at the top.
In cases where the light is required to shew in one direction only the flame
chamber may conveniently have the form of one cone closed at its small end, its
base being against one side of the lamp, and orifices being formed in its under and
upper parts to admit the burner and chimney.
In another arrangement two frustums of cones (which I will call cones) not
joined together as before described are arranged vertically; the base of one cone is
on the bottom of the lamp, or on a bottom plate, the other cone is inverted, and
suitably fixed in the upper part of the lamp. A space is left between the small
ends of the upper and lower cones. In the opening of the small end of the lower
cone is placed a burner, and enclosed in the lower cone is an oil tank. In the
opening in the smaller end of the upper cone is placed the chimney.
The head of the lamp may be similar to that used in the lamps last described,
but the air for feeding the flame is brought from the upper to the lower part of the
lamp by means of two or more tubes or channels, whose open tops are above the
level of the top or highest part of the upper cone, and their open bottoms enter
the bottom chamber beneath the base of the lower cone. A glass annulus, or it
may be a lens, surrounds the two cones, so that air shall be excluded, except so far
as entering at the top. It can make its way down the air tubes, and thence
through the burner and up the chimney.
In another arrangement, on a lamp body of suitable shape I place a top, such as
referred to in Specification No. 1795 of 1876, and below this top I form holes in
the sides of the lamp for the admission of air, protecting them by a wind guard or
guards. Immediately below I fix a metal plate of the size of the interior of the
lamp body. This I call a top plate, and it forms a double top. In the centre of
the top plate I insert a metal chimney, which extends upwards towards the top
of the lamp and downwards towards the flame, according to requirement. From
above the top plate air passages extend downwards into the double bottom of the
lamp. Three closed sides of the lamp form three sides of a box or chamber, of
which the oil roservoir and ledges supporting it form the top, and the lamp bottom
the lower part. On the fourth or door side is a piece of metal, which fills the
opening left, and renders the chamber air-tight when the door is closed. The only
orifices in this chamber are those occupied by the burner and air passages.
entering the holes in the sides of the lamp passes down the air passages into the
bottom chamber, and thence through the burner and up the chimney.
Air
In another arrangement, in constructing the flame chamber I use a lamp-bowl
cast with air passages extending from the top edge of the bowl to a glass or metal
chamber in the bottom of the bowl. In this chamber I place a metal tube of less
depth than the chamber, and perforated in parts not directly exposed to the air
passages; or the two air passages may be joined beneath the burner by means of a
perforated metal or other tube.
A reflector of suitable shape is fitted close to the top of the bowl. A metal
chimney is fitted into this reflector; above is arranged an oil tank; the tubes
leading from it pass through the reflector and down to the burner.
Around the outside of the burner is a tube, which, when the lamp is dropped
into its place fits close round the glass chamber in the bowl before referred to.
Over the wick holder or burner is a cone, which fits closely to the tube encircling
the burner.
The arrangement just described may be modified as follows:-Metal air arms
may be used opening above the reflector and passing through it, the air conveyed
through them being discharged into a small cylindrical air-tight chamber, whose
bottom is closed by the glass of the bowl
To guard against the effects of overflow I may slightly curve the bottom of the

page_text: bowl upwards, and cut slots in the air-tight chamber to allow the oil which may
accidentally overflow to run away clear of the burner. By this arrangement I also
get a small supply of air through to the bowl, which helps to cool the heated air
contained therein.
The air arms are made so as to be moveable. After passing through the reflector
they enter a corresponding piece of tube fixed to the reflector, and are then secured
by a suitable fastening.
In the upper portion of the lamp are holes for the admission of air. The only
way by which the flame can be fed with air is therefore by its passage down the
air passages or tubes referred to above.
As is obvious other arrangements of apparatus constructed on a similar principle
may be employed for carrying my Invention into effect.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Thomas Cooper Thomas in the Great Seal Patent Office on the
16th August 1878.
JOHN THOMAS COOPER THOMAS, of 54, 55, and 56, Minories, in the County of
Middlesex, Assistant to Messieurs Ridsdale and Company, Lamp Manufacturers.
" IMPROVEMENTS IN LAMPS."
My Invention relates more especially to lamps exposed to wind or draughts, and
wherein glass chimneys are objectionable, as in railway, ships' signal, and other
lamps.
In my improved lamps the flame is in a suitable glazed chamber (herein-after
called the flame chamber) closed to the external atmosphere except at and above
the burner; the air necessary to support combustion is admitted at the upper part
of the lamp, passes downward and enters the flame chamber through the burner or
slot, and the products of combustion escape by a metal chimney above.
In order that my Invention may be clearly understood I will now describe, with
reference to the accompanying Drawings, the manner of carrying it into practical
effect.
Fig. 1 is a vertical section, Fig. 2 a horizontal section in the line A, B, of Fig. 1,
and Fig. 3 a part side view of a lamp according to my Invention. In this
arrangement the flame chamber 1 has in vertical section in one direction the form
of two frustums of cones joined at their smallest diameters 2, and fitted into the
lamp with their axes horizontal, and their bases against opposite sides of the lamp.
In front of each base is glass 3, which is shewn as being plain, but may be in the
form of a lens, moveable or otherwise. The interior of the chamber 1 thus formed
may be reflective.
In the narrow part 2 of the chamber, at the under side, is a hole large enough to
admit a burner 4; above it is a hole for the chimney 5.
The lamp case 6, beneath the above-described chamber 1, is made air-tight, and
contains or supports an oil reservoir 7 and wick holder 8, which can be got at by

page_text: opening or removing that part of the lamp containing the flame chamber 1. Above
this chamber (1) are holes 9, in the lamp case 6, to admit air, such holes being
protected by a wind guard 10, or more than one wind guard may be used if required.
The top or head of the lamp is shewn as being similar to that described in the
Specification of Davis and Thomas' Patent of 28 April 1876, No. 1795.
The air entering by the holes 9, in the upper part of the lamp, passes down out-
side the flame chamber 1 to the flame at 11, and, after combustion, passes up the
chimney 5 and out at the top.
Fig. 4 shews a modification of flame chamber suitable for use in cases where the
light is required to shew in one direction only. The flame chamber 1 in this
arrangement has the form of one cone closed at its small end 2, its base being
arranged to lie against one side of the lamp, and orifices being formed in its under
and upper parts to admit respectively the burner 4 and the chimney 5.
Figs. 5, 6, and 7 shew respectively in vertical section, in horizontal section in the
line C, D, of Fig. 5, and in horizontal section in the line E, F, of Fig. 5, another
modification of my Invention. In this arrangement two frustums of cones (which
I will call cones 12, 13) not joined together as before described are arranged
vertically. The base of the one cone 13 is on a flange 14, or it may be on the
bottom of the lamp; the other cone (12) is inverted, and suitably fixed in the upper
part of the lamp, as shewn. A space 2 is left between the small ends of the upper
and lower cones. In the opening of the small end of the lower cone 13 is placed a
burner 4, and enclosed in the lower cone 13 is an oil tank 7. In the opening in the
smaller end of the upper cone 12 is placed the chimney 5.
The head of the lamp is similar to that used in the lamps last described, but the
air for feeding the flame is brought from the upper to the lower part of the lamp by
means of tubes or channels 6*, whose open tops are above the level of the top or
highest part of the upper cone 12, and their open bottoms enter the bottom chamber
beneath the base of the lower cone 13. A glass annulus 3 (or it may be a lens)
surrounds the two cones 12 and 13, so that air shall be excluded, except so far as
entering at the top (through the holes 9); it can make its way down the air tubes
6*, and thence through the burner 4 and up the chimney 5. In the Drawing
four air tubes or channels 6* are shewn, but the number may be varied to suit
circumstances.
Figs. 8 and 9 shew respectively in vertical section and in horizontal section
another modification of my Invention. In this arrangement, on a lamp body 6 of
suitable shape I place a top 15, such as referred to in the Specification of the Patent
herein-before mentioned, and below this top I form holes 9 in the sides of the lamp
for the admission of air, protecting them by a wind guard 10; or more than one
wind guard may be used. Immediately below I fix a metal plate 16 of the size of
the interior of the lamp body; this I call a top plate, and it forms a double top. In
the centre of the top plate I insert a metal chimney 5, which extends upwards
towards the top 15 of the lamp, and downwards towards the flame, according to
requirement. From above the top plate air passages 6* extend downwards into the
double bottom of the lamp. Three closed sides 17 of the lamp form three sides of a
box or chamber, of which the oil reservoir 7 and ledges 18 supporting it form the
top, and the lamp bottom the lower part. On the fourth or door side 19 is a piece
of metal which fills the opening left, and renders the chamber air-tight when the
door is closed. The only orifices in this chamber are those occupied by the burner
and air passages. Air entering the holes 9 in the sides of the lamp passes down the
air passages 6× into the bottom chamber, and thence through the burner 4 and up
the chimney 5.
Figs. 10, 11, and 12 shew another modification of my Invention, Fig. 10 being a
vertical section of the lamp, Fig. 11 a plan shewing the interior of the glass bowl,
herein-after mentioned, and Fig. 12 a plan of the reflector. In this arrangement, in
constructing the flame chamber 1, I use a lamp bowl 1* cast with air passages 6×
extending from the top edge of the bowl to a glass or metal chamber 20 in the
bottom of the bowl; in this chamber 20 I place a metal tube 21 of less depth than

page_text: the chamber 20, and perforated in parts not directly exposed to the air passages; or
the two air passages may be joined beneath the burner by means of a horizontal per-
forated metal or other tube. A reflector 22 of the shape shewn, or other suitable
shape, is fitted close to the top of the bowl 1*; a metal chimney 5 is fitted into this
reflector; above is arranged an oil tank in the space 7; the tubes 23, leading from
it pass through the reflector and down to the burner 4; 4* is the moveable wick
holder; around the outside of the burner 4 is a tube 24, which when the lamp is
dropped into its place fits close round the glass chamber in the bowl above referred
to; over the wick holder or burner is a cone 25, which fits closely to the tube
encircling the burner.
The arrangement just described may be modified, as shewn in Figs. 13 and 14,
where metal air arms 6* are used, opening above the reflector 22, and passing
through it, the air conveyed through them being discharged into a small cylin-
drical air-tight chamber 20, whose botton is closed by the glass of the bowl.
To guard against the effects of overflow I may slightly curve the bottom of the
bowl upwards, and cut slots in the air-tight chamber 20 to allow the oil which
may accidentally overflow to run away clear of the burner. By this arrangement !
also get a small supply of air through to the bowl, which helps to cool the heated
air contained therein.
The air arms are made so as to be moveable. After passing through the reflector
they enter a corresponding piece of tube 26 fixed to the reflector, and are there
secured by a suitable fastening.
In the upper portion of the lamp are holes 9 for the admission of air. The only
way by which the flame can be fed with air is therefore by its passage down the air
passages or tubes 0x, referred to above.
Having described the nature of iny said Invention, and explained the manner of
carrying it into practical effect, I hereby declare that what I consider to be novel
and original, and therefore claim as secured to me under the Letters Patent
herein-before in part recited is,-
1. Enclosing the flame in a chamber closed to the external atmosphere, except at
and above the burner, and causing the air for supporting combustion entering at
the upper part of the lamp to pass downward and to enter the flame chamber
through the slot or burner, and the products of combustion to escape through the
upper opening in the flame chamber by a metal chimney, all substantially as
described.
2. The construction of lamp shewn in and described with reference to Figs. 1, 2,
and 3 of the accompanying Drawings.
3. The arrangement described with reference to Fig. 4 of the Drawings.
4. The construction of lamp shewn in and described with reference to Figs. 5, 6,
and 7 of the Drawings.
5. The construction of lamp shewn in and described with reference to Figs. 8
and 9 of the Drawings.
6. The construction of lamp shewn in and described with reference to Figs. 10, 11,
and 12 of the Drawings.
7. The construction of lamp shewn in and described with reference to Figs. 13
and 14 of the Drawings.
In witness whereof, I, the said John Thomas Cooper Thomas, have hereunto
set my hand and seal, this Thirteenth day of August, in the year of our Lord
One thousand eight hundred and seventy-eight.
J. T. C. THOMAS. (L.S.)

page_text: LETTERS PATENT to John Thomas Cooper Thomas, of 54, 55, and 56, Minories,
in the County of Middlesex, Assistant to Messieurs Ridsdale and Company,
Lamp Manufacturers, for the Invention of "IMPROVEMENTS IN LAMPS."
"
PROVISIONAL SPECIFICATION left by the said John Thomas Cooper Thomas
at the Office of the Commissioners of Patents on the 19th February 1878.
JOHN THOMAS COOPER THOMAS, of 54, 55, and 56, Minories, in the County of
Middlesex, Assistant to Messieurs Ridsdale and Company, Lamp Manufacturers.
IMPROVEMENTS IN LAMPS."
My Invention relates more especially to lamps exposed to wind or draughts, and
wherein glass chimneys are objectionable, as in railway, ships' signals, and other
lamps.
In my improved lamps the flame is in a suitable glazed chamber (herein-after
called the flame chamber) closed to the external atmosphere except at and above
the burner. The air necessary to support combustion is admitted at the upper
part of the lamp, passes downward, and enters the flame chamber through the
burner or slot, and the products of combustion escape by a metal chimney above.
In one arrangement the flame chamber has in vertical section in one direction
the form of two frustums of cones joined at their smallest diameters and fitted into
the lamp with their axes horizontal and their bases against opposite sides of the
lamp. In front of each base is glass, either plain or in the form of a lens, moveable
or otherwise. The interior of the chamber thus formed may be reflective.
In the narrow part of the chamber at the under side is a hole large enough to
adınit a burner; above it is a hole for the chimney.
The lamp case beneath the above-described chainber is made air-tight, and con-
tains or supports an oil reservoir and wick holder, which can be got at by opening
or removing that part of the lamp containing the flame chamber.
Above this
chamber are holes in the lamp case to admit air, such holes being protected by a
wind guard or guards.

page_text: The top or head of the lamp may be similar to that described in the Specification
of Davis and Thomas' Patent of 28th April 1876, No. 1795.
The air entering by the holes in the upper part of the lamp passes down outside
the flame chamber to the flame, and after combustion passes up the chimney and
out at the top.
In cases where the light is required to shew in one direction only the flame
chamber may conveniently have the form of one cone closed at its stall end, its
base being against one side of the lamp, and orifices being formed in its under and
upper parts to admit the burner and chimney.
In another arrangement two frustums of cones (which I will call cones) not
joined together as before described are arranged vertically; the base of one cone is
on the bottom of the lamp, or on a bottom plate, the other cone is inverted, and
suitably fixed in the upper part of the lamp. A space is left between the small
ends of the upper and lower cones. In the opening of the small end of the lower
cone is placed a burner, and enclosed in the lower cone is an oil tank. In the
opening in the smaller end of the upper cone is placed the chimney.
The head of the lamp may be similar to that used in the lamps last described,
but the air for feeding the flame is brought from the upper to the lower part of the
lamp by means of two or more tubes or channels, whose open tops are above the
level of the top or highest part of the upper cone, and their open bottoms enter
the bottom chamber beneath the base of the lower cone A glass annulus, or it
may be a lens, surrounds the two cones, so that air shall be excluded, except so far
as entering at the top. It can make its way down the air tubes, and thence
through the burner and up the chimney.
In another arrangement, on a lamp body of suitable shape I place a top, such as
referred to in Specification No. 1795 of 1876, and below this top I form holes in
the sides of the lamp for the admission of air, protecting them by a wind guard or
guards. Immediately below I fix a metal plate of the size of the interior of the
lamp body. This I call a top plate, and it forms a double top. In the centre of
the top plate I insert a metal chimney, which extends upwards towards the top
of the lamp and downwards towards the flame, according to requirement. From
above the top plate air passages extend downwards into the double bottom of the
lamp. Three closed sides of the lamp form three sides of a box or chamber, of
which the oil reservoir and ledges supporting it form the top, and the lamp bottom
the lower part.
On the fourth or door side is a piece of metal, which fills the
opening left, and renders the chamber air-tight when the door is closed. The only
orifices in this chamber are those occupied by the burner and air passages.
ontering the holes in the sides of the lamp passes down the air passages into the
bottom chamber, and thence through the burner and up the chimney.
Air
In another arrangement, in constructing the flame chamber I use a la:np-bowl
cast with air passages extending from the top edge of the bowl to a glass or metal
chamber in the bottom of the bowl. In this chamber I place a metal tube of less
depth than the chainber, and perforated in parts not directly exposed to the air
passages; or the two air passages may be joined beneath the burner by means of a
perforated metal or other tube."
A reflector of suitable shape is fitted close to the top of the bowl. A metal
chinney is fitted into this reflector; above is arranged an oil tank; the tubes
leading from it pass through the reflector and down to the burner.
Around the outside of the burner is a tube, which, when the lamp is dropped
into its place fits close round the glass chamber in the bowl before referred to
Over the wick holder or burner is a cone, which fits closely to the tube encircling
the burner.
The arrangement just described may be modified as follows:-Metal air arms
may be used opening above the reflector and passing through it, the air conveyed
through thein being discharged into a small cylindrical air-tight chamber, whose
bottom is closed by the glass of the bowl.
To guard against the effects of overflow I may slightly curve the bottom of the

page_text: bowl upwards, and cut slots in the air-tight chamber to allow the oil which may
accidentally overflow to run away clear of the burner. By this arrangement I also
get a small supply of air through to the bowl, which helps to cool the heated air
contained therein.
The air arms are made so as to be moveable. After passing through the reflector
they enter a corresponding piece of tube fixed to the reflector, and are then secured
by a suitable fastening.
In the upper portion of the lamp are holes for the admission of air. The only
way by which the flame can be fed with air is therefore by its passage down the
air passages or tubes referred to above.
As is obvious other arrangements of apparatus constructed on a similar principle
may be employed for carrying my Invention into effect.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Thomas Cooper Thomas in the Great Seal Patent Office on the
16th August 1878.
JOHN THOMAS COOPER THOMAS, of 54, 55, and 56, Minories, in the County of
Middlesex, Assistant to Messieurs Ridsdale and Company, Lamp Manufacturers.
"IMPROVEMENTS IN LAMPS."
My Invention relates more especially to lamps exposed to wind or draughts, and
wherein glass chimneys are objectionable, as in railway, ships' signal, and other
lamps.
In my improved lamps the flame is in a suitable glazed chamber (herein-after
called the flame chamber) closed to the external atmosphere except at and above
the burner; the air necessary to support combustion is admitted at the upper part
of the lamp, passes downward and enters the flame chamber through the burner or
slot, and the products of combustion escape by a metal chimney above.
In order that iny Invention may be clearly understood I will now describe, with
reference to the accompanying Drawings, the manner of carrying it into practical
effect.
Fig. 1 is a vertical section, Fig. 2 a horizontal section in the line A, B, of Fig. 1,
and Fig. 3 a part side view of a lanp according to my Invention. In this
arrangement the flame chamber 1 has in vertical section in one direction the form
of two frustums of cones joined at their smallest diameters 2, and fitted into the
lamp with their axes horizontal, and their bases against opposite sides of the lamp.
In front of each base is glass 3, which is shewn as being plain, but may be in the
form of a lens, inoveable or otherwise. The interior of the chamber 1 thus formed
may be reflective.
In the narrow part 2 of the chamber, at the under side, is a hole large enough to
admit a burner 4; above it is a hole for the chimney 5.
The lamp case 6, beneath the above described chamber 1, is made air-tight, and
contains or supports an oil reservoir 7 and wick holder 8, which can be got at by

page_text: opening or removing that part of the lamp containing the flame chamber 1. Above
this chamber (1) are holes 9, in the lamp case 6, to admit air, such holes being
protected by a wind guard 10, or more than one wind guard may be used if required.
The top or head of the lamp is shewn as being similar to that described in the
Specification of Davis and Thomas' Patent of 28 April 1876, No. 1795.
The air entering by the holes 9, in the upper part of the lamp. passes down out-
side the flame chainber 1 to the flame at 11, and, after combustion, passes up the
chimney 5 and out at the top.
Fig. 4 shews a modification of flame chamber suitable for use in cases where the
light is required to show in one direction only. The flame chamber 1 in this
arrangement has the form of one cone closed at its small end 2, its base being
arranged to lie against one side of the lamp, and orifices being formed in its under
and upper parts to admit respectively the burner 4 and the chimney 5.
Figs. 5, 6, and 7 shew respectively in vertical section, in horizontal section in the
line C, D, of Fig. 5, and in horizontal section in the line E, F, of Fig. 5, another
modification of my Invention. In this arrangement two frustums of cones (which
I will call cones 12, 13) not joined together as before described are arranged
vertically. The base of the one cone 13 is on a flange 14, or it may be on the
bottom of the lamp; the other cone (12) is inverted, and suitably fixed in the upper
part of the lamp, as shewn. A space 2 is left between the small ends of the upper
and lower cones. In the opening of the small end of the lower cone 13 is placed a
burner 4, and enclosed in the lower cone 13 is an oil tank 7. In the opening in the
smaller end of the upper cone 12 is placed the chimney 5.
The head of the lamp is similar to that used in the lamps last described, but the
air for feeding the flame brought from the upper to the lower part of the lamp by
means of tubes or channels 6*, whose open tops are above the level of the top or
highest part of the upper cone 12, and their open bottoms enter the bottom chamber
beneath the base of the lower cone 13. A glass annulus 3 (or it may be a lens)
surrounds the two cones 12 and 13, so that air shall be excluded, except so far as
entering at the top (through the holes 9); it can make its way down the air tubes
6*, and thence through the burner 4 and up the chimney 5. In the Drawing
four air tubes or channels 6* are shewn, but the number may be varied to suit
circumstances.
:
Figs. 8 and 9 shew respectively in vertical section and in horizontal section
another modification of my Invention. In this arrangement, on a lamp body 6 of
suitable shape I place a top 15, such as referred to in the Specification of the Patent
herein-before mentioned, and below this top I forin holes 9 in the sides of the lamp
for the admission of air, protecting them by a wind guard 10; or more than one
wind guard may be used. Immediately below I fix a metal plate 16 of the size of
the interior of the lamp body; this I call a top plate, and it forms a double top. In
the centre of the top plate I insert a metal chinney 5, which extends upwards
towards the top 15 of the lamp, and downwards towards the flame, according to
requirement. From above the top plate air passages 6* extend downwards into the
double bottom of the lamp. Three closed sides 17 of the lainp forin three sides of a
box or chamber, of which the oil reservoir 7 and ledges 18 supporting it form the
top, and the lanp bottom the lower part. On the fourth or door side 19 is a piece
of metal which fills the opening left, and renders the chamber air-tight when the
door is closed. The only orifices in this chamber are those occupied by the burner
and air passages.
Air entering the holes 9 in the sides of the lamp passes down the
air passages 6 into the bottom chamber, and thence through the burner 4 and up
the chimney 5.
Figs. 10, 11, and 12 shew another modification of my Invention, Fig. 10 being a
vertical section of the lamp, Fig. 11 a plan shewing the interior of the glass bowl,
herein-after mentioned, and Fig. 12 a plan of the reflector. In this arrangement, in
constructing the flame chamber 1, I use a lamp bowl 1* cast with air passages 6×
extending from the top edge of the bowl to a glass or metal chamber 20 in the
bottom of the bowl; in this chamber 20 I place a metal tube 21 of less depth than

page_text: the chamber 20, and perforated in parts not directly exposed to the air passages; or
the two air passages inay be joined beneath the burner by means of a horizontal per-
forated inetal or other tube. A reflector 22 of the shape shewn, or other suitable
shape, is fitted close to the top of the bowl 1×; a metal chimney 5 is fitted into this
reflector; above is arranged an oil tank in the space 7; the tubes 23, leading from
it pass through the reflector and down to the burner 4; 4* is the moveable wick
holder; around the outside of the burner 4 is a tube 24, which when the lamp is
dropped into its place fits close round the glass chamber in the bowl above referred
to; over the wick holder or burner is a cone 25, which fits closely to the tube
encircling the burner.
The arrangement just described may be modified, as shown in Figs. 13 and 14,
where metal air arms 6* are used, opening above the reflector 22, and passing
through it, the air conveyed through them being discharged into a small cylin-
drical air-tight chamber 20, whose bottom is closed by the glass of the bowl.
To guard against the effects of overflow I may slightly curve the bottom of the
bowl upwards, and cut slots in the air-tight chamber 20 to allow the oil which
may accidentally overflow to run away clear of the burner. By this arrangement I
also get a small supply of air through to the bowl, which helps to cool the heated
air contained therein.
The air arms are made so as to be moveable. After passing through the reflector
they enter a corresponding piece of tube 26 fixed to the reflector, and are there
secured by a suitable fastening.
In the upper portion of the lamp are holes 9 for the admission of air.
The only
way by which the flame can be fed with air is therefore by its passage down the air
passages or tubes 6×, referred to above.
Having described the nature of iny said Invention, and explained the manner of
carrying it into practical effect, I hereby declare that what I consider to be novel
and original, and therefore claim as secured to me under the Letters Patent
herein-before in part recited is,-
1. Enclosing the flame in a chamber closed to the external at.nosphere, except at
and above the burner, and causing the air for supporting combustion entering at
the upper part of the lamp to pass downward and to enter the flaine chainber
through the slot or burner, and the products of combustion to escape through the
upper opening in the flaine chamber by a metal chimney, all substantially as
described.
2. The construction of lamp shewn in and described with reference to Figs. 1, 2
and 3 of the accompanying Drawings.
3. The arrangement described with reference to Fig. 4 of the Drawings.
4. The construction of lamp shewn in and described with reference to Figs. 5, 6,
and 7 of the Drawings.
5. The construction of lamp shewn in and described with reference to Figs. 8
and 9 of the Drawings.
6. The construction of lamp shewn in and described with reference to Figs. 10,11,
and 12 of the Drawings.
7. The construction of lamp shown in and described with reference to Figs. 13
and 14 of the Drawings.
In witness whereof, I, the said John Thomas Cooper Thomas, have hereunto
set iny hand and seal, this Thirteenth day of August, in the year of our Lord
One thousand eight hundred and seventy-eight."
J. T. C. THOMAS. L.S.)