IMPROVEMENTS IN THE APPLICATION OF GAS, POR PRODUCING AND RADIATING HEAT
Year: 1849

page_text: I TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
OWEN EDWARDS, of Sydney Place, Brompton, in the County of Middlesex,
Surgeon, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of Great Britain, bearing date at Westminster,.
the Twentieth day of September, in the thirteenth year of Her reign, did
give and grant unto me, the said David Owen Edwards, my exors, .admors,,
and assigns, Her especial license, full power, sole privilege and authority, that
I, the said David Owen Edwards, my exors, adiñors, and assigns, and such.
others as I, the said David Owen Edwards, my exors, adññiors, or assigns,
should at any time agree with, and no others, from time to time and at all
times thereafter during the term of years therein expressed, should and law-
fully might make, use, .exercise, and vend, within that part.of. the United:
Kingdom of Great Britain and. Ireland called England, Her. Dominion of.
Wales, and Town of Berwick-upon-Tweed, and also in the Islands of Jersey,
Guernsey, Alderney, Sark, and Man, and in all Her said Majesty's Colonies and
Plantations abroad, my Invention of "IMPROVEMENTS IN THE APPLICATION OF GAS,
POR PRODUCING AND RADIATING HEAT;" in which said Letters Patent there is con-
tained a proviso requiring that I, the said David Owen Edwards, shall particularly
describe and ascertain the nature of my said Invention, and in what manner the
same is to be performed, by an instrument in writing under my hand and seal,
and cause the same to be inrolled in Her said Majesty's High Court of

page_text: Chancery within six calendar months next and immediately after the date
of the said in part récited Letters Patent,. as, reference being thereunto
had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
David Owen Edwards, do hereby declare that the nature of my said In-
vention, and the manner in which the same is to be performed, are particu-
larly described and ascertained in and by this Specification and Instrument in
writing under my hand and seal, reference being had to the several Drawings
or Figures hereunto annexed, and in which said several Drawings similar parts
are marked and referred to by similar letters or characters (that is to say):-
My Invention relates to certain improved applications of gas for the produc-
tion and radiation of heat, and consists,-
Firstly, in certain apparatus for the combustion of gas for the production
and radiation of heat; and,
Secondly, in certain arrangements and combinations of such apparatus in
stoves and cooking apparatus, for the production, radiation, and application of
heat in a more economical and agreeable manner than hitherto. And I would
remark that my Invention is intended to apply principally to coal gas, but it
is also applicable to hydrogen and other inflammable gases..
Sheet I., Figure 1, of the Drawings hereunto annexed, represents one of my
improved burners, consisting of a hollow bulb of pipeclay perforated with a
number of small holes; Figure 2 is a vertical section of the same; and
Figure 3 a horizontal. section. It is made with a hollow stem to admit the
gas. In using this.burner with coal gas, if the gas is supplied with two great
rapidity a bright flame will be produced at each hole, but by reducing the
supply of gas it will be found that air enters at some of the lower holes, and,
mixing with the gas, causes it to burn with a pale blue flame. In a short
time the bulb becomes red. hot, and is covered with a thin envelope of pale
flame, and much resembles in appearance a piece of glowing charcoal. It is;
thus much better adapted than an ordinary burner for diffusing heat by.
radiation, while at the same time, owing to the nature of the material, the loss
of heat by conduction is comparatively small. The bulb may be made of any
required form, and it may be made in one piece with the stem, or it may be
fitted on a separate stem of the same material; or of metal. It may be placed
in any position, either horizontal, vertical, or inclined.
Figures 4, 5, and 6 shew various forms of burners. Figure 7 is a form
which may be used for boiling liquids contained in a vessel placed; over it, and
for other culinary operations. It is in the form of a funnel, the top being
covered, and perforated with minute holes like the sides.

page_text: Figure 8 shews an arrangement of several bulbs placed in a circle, and
adapted for roasting meat.
Figure 9 shews a front view of an oven containing an arrangement of
burners like that shewn in Figure 8. These burners A are cemented by
plaster of Paris, or other suitable cement, into a hollow slab of earthenware B,
into which gas is introduced by the pipe C. D is a small opening through,
which the products of combustion pass away into a chimney or elsewhere.
The oven may be of metal; but I prefer to build it of brickwork or earthen-
ware, and to line it with porcelain tiles, which reflect the heat to the meat
which is placed in the centre on a trivet standing in a dish, or suspended from
the top of the oven. The oven may also be used for boiling and stewing, the
saucepans or other vessels being supported over the flame. The oven thus
forms a hot-chamber, economizing the heat, which is reflected on the saucepans
by the sides of the oven, as is well understood. Figure 10 is a front view,.
Figure 11 a side view, and Figure 12 a section of a stove for beating
apartments. It contains a hollow piece of earthenware F, which is shewn in
section on a larger scale in Figure 13, and in plan in Figure 14. This is per-
forated with several holes, into which are cemented the stems of a number of
burners A, A. A pipe C'introduces the gas to the piece F, on which is fitted a
cylinder of earthenware G, closed at the top, but having an opening in front
at H, and a pipe I leading into a chimney. The opening H is fitted to a
corresponding opening in the outer cylinder of earthenware K, on which is
á cover M perforated with holes. Air is admitted at the bottom of the stove,
either through holes at the sides or through a grating in the floor, as shewn
at N, in Figure 12. This air rises in the double casing formed by the two
cylinders of earthenware G and K, and becoming warmed enters the room.
At the same time heat radiates into the room from the external cylinder K and
also from the opening H,,through which is seen the glowing fire.
The
proximity of the bulbs causes them to react on one another, thereby increasing
their temperature, If it is not wished to have the fire visible, a door may
be provided to close the opening H; or that opening may be reduced to about
two inches in diameter, or just sufficient for the purpose of lighting the gas;-
a few openings are then made round the lower part of the cylinder G to
admit air to support the combustion. The air which rises between the cylinders
G and K in Figure 12 is admitted through the floor, and supplied by a pipe
passing under the floor, and open to the external air. By this means a continual
supply of fresh air is introduced into the apartment, and this air is warmed by
contact with the earthenware surfaces of the stove. At the same time the
combustion of the gas produces a draught in the chimney, and the air of'

page_text: the apartment is constantly being drawn in at the opening H, so that a
constant ventilation of the apartment is produced. The stove may be made of
iron or other metal; but I prefer to employ earthenware or porcelain, as
being less likely to contaminate the air which comes in contact with it.
Sheet II., Figure 15, shews a front view, and Figure 16 a section of an
arrangement already mentioned, in which the bulb A is supported on an
iron stem or tube T. This tube is closed at the top, and the gas enters
the bulb through a hole or holes in the side of the tube at S. Figure 17.
is a front view, and Figure 18 a section of another form. A is the perforated
bulb, made with a socket at the lower part which fits on the tube T. In
these arrangements it is not necessary to cement the bulb to the tube.
In applying these arangements to a stove like that shewn in Figures 10, 11,
and 12, Sheet I., the piece F may be conveniently made of cast iron or
other metal, and the iron stems screwed into it, or the piece F may be
made of solid earthenware, and two annular wrought iron pipes laid upon it,
with the metal stems screwed into them.
Sheet II., Figure 19, shews a section of an oven with a circle of burners
supported on iron stems screwed into the annular pipe B, which is shewn
in plan in Figure 20. D is a pan for receiving the dripping when meat is
being roasted. In a similar manner my improved burners may be applied to
many of the gas stoves at present in use for cooking and warming apartments.
Figure 21 shews a plan and Figure 22 a vertical section of a gas gridiron
for broiling chops and other articles. The chops are laid on the upper
bars P, P, which are inclined towards the front, and grooved so as to carry
the gravy to a pan placed to receive it. Q, Q, are similar bars to convey to
the pan any gravy which may drop through between the upper bars. A, A, are
the burners, which are protected from the falling gravy and grease by the bars.
The meat is cooked partly by the heat radiated from the burners, and partly
by the hot air and products of combustion which ascend between the bars.
This apparatus may be used without the upper bars P, P, the meat being
placed on the lower bars, and a tray placed under the burners to receive the
gravy or grease which drops from it.
Figure 23 shews a plan and Figure 24 a vertical section of another form of
my Invention. A is an earthenware vessel, the top of which is perforated with
a number of small holes, whilst the bottom is open. T is a tube introducing gas
into the interior, where it mixes with atmospheric air, and is burnt on the
surface of the perforated top. Figure 25 shews a section of a similar apparatus
in which the top only (A) of the vessel is made of earthenware, the rest being
of sheet iron. These last-described arrangements are somewhat similar

page_text: to some of the ordinary gas stoves, in which a mixture of gas and atmospheric
air is burnt on the surface of a sheet of wire gauze; but there is this material
difference, that I employ perforated earthenware instead of wire gauze,
which is subject to injury from heat and oxidation. These perforated
earthenware plates may be made flat or curved, and may be applied in
various ways. Various sorts and mixtures of argillaceous materials may be
used for the burners and also for the stoves and ovens. I have found
pipe clay and mixtures of pipe clay and fire clay to answer perfectly for the
burners, some of the forms of which are conveniently made in moulds in the
same way that tobacco pipes are made. The top is afterwards closed by hand,
and a number of minute holes of about one-fiftieth of an inch in diameter are
pierced with a pin or a small brad awl. The burners are then baked in a kiln,
and are fit for use. They may be colored by oxide of copper or other metallic
oxides, of desired. For the inner chamber G of the stove, shewn in Figure
12, Sheet I., I employ a mixture of one part by weight of burnt pipeclay,
such as broken tobacco pipes, and two parts of fire-clay, and I slackly burn it
in a kiln. I find that this mixture is not apt to crack from the changes of
temperature to which it is subjected. The outer casing K may be of the same
material, or it may be of stoneware, porcelain, terra cotter, or other argilla-
ceous material. Stoves constructed of these materials may also be used with
the common forms of gas burners, and will be found more cleanly and may
be made more elegant than the ordinary black cast-iron gas stoves.
Figure 26, Sheet II., shews an arrangement of my improved burners, placed
in the centre of a bright cast-iron reflector, which reflects the heat and light
into the apartment.
Figure 27 shews a section of the same. A, A, are the burners supplied
with gas by the branches B, B, from the pipe C. D is a back of earthenware
or fire-brick. The products of combustion escape up the chimney behind the
reflector.
Figure 28 shews a plan of a stove in the form of a cubical chest, with four
reflectors, and a system of burners in each reflector, the view of each side
being the same as Figure 26. The products of combustion pass into the
chest and round the reflectors, and escape by a flue passing down through the
floor and into a chimney. This stove is adapted for heating bankers' offices
and other large apartments.
Having now described my Invention, and the manner in which the same
is to be performed, I wish it to be understood that I do not claim as of my
Invention the application of gas for the production and radiation of heat, the
samne having been used with metal burners in various kinds of stoves and

page_text: cooking apparatus. And it will be obvious that the forms of my improved
burners may be varied, and that other arrangements of stoves and apparatus
may be adopted than those shewn in the Drawings; also that various descrip-
tions of clays may be employed for the purposes of my Invention..
And I hereby declare that I claim as improvements in the application of
gas for producing and radiating heat,-
Firstly, the construction of gas burners of pipe-clay or other argillaceous
material perforated with holes, and adapted for the production and radiation
of heat, as above described.
Secondly, I claim the construction of stoves of earthenware or other
argillaceous material with a double casing, for the passage of the air, in
combination with burners constructed and arranged as above described, for
the production and radiation of heat by the combustion of gas.
Thirdly, I claim the construction of ovens or cooking chambers of earthen-
ware or other argillaceous material, in combination with burners constructed
and arranged as above described, for the production and radiation of heat by
the combustion of gas.
In witness whereof, I, the said David Owen Edwards, have hereunto
set my hand and seal, this Nineteenth day of March, One thousand
aight hundred and fiftee
DAVID OWEN (L.s.) EDWARDS.
AND BE IT REMEMBERED, that on the Nineteenth day of March,
in the year of our Lord 1850, the aforesaid David Owen Edwards came
before our said Lady the Queen in Her Chancery, and acknowledged the
Specification aforesaid, and all and every thing therein contained and specified,
in form above written. And also the Specification aforesaid was stamped
according to the tenor of the Statute made for that purpose.