IMPROVE- MENTS IN GAS LAMPS."
Year: 1880

page_text: LETTERS PATENT to Charles William Siemens, of Queen Anne's Gate,
Westminster, in the County of Middlesex, for an Invention of "IMPROVE-
MENTS IN GAS LAMPS."
PROVISIONAL SPECIFICATION left by the said Charles William Siemens
at the Office of the Commissioners of Patents on the 13th November 1880.
CHARLES WILLIAM SIEMENS, of Queen Anne's Gate, Westminster; in the County
of Middlesex. "IMPROVEMENTS IN GAS LAMPS.".
The brilliancy of a gas flame is augmented when the air supporting its
combustion is heated..
.
"
My Invention relates to a construction of gas lamp wherein the air supporting.
the combustion of the flame is heated by the products of the combustion. For this
purpose I place immediately above the flame a grating or other extended surface of
copper or other metal of high conductivity, on which the hot products of combustion
impinge, heating it. Immediately below or at the side of the burner I place a
grating or extended metallic surface for heating the air, flowing through passages
or perforations in it to supply the flame. This surface is made in one piece with
or is in immediate metallic connection with the upper surface, so that a large
portion of the heat of the combustion is transferred by conduction. to the lower
surface. This construction may be applied to a burner of the open kind, such as
the bat's-wing, or to an enclosed burner, such as the argand, in which latter case a
glass chimney is interposed between the upper and lower heating surfaces. In
order more fully to utilise the heat, it is of advantage.to cover the external surfaces,
particularly that of the lower heater, with imperfectly conducting material, such as
asbestos or ceramic material. The metallic connection of the upper and lower..
heaters may be of wedge shaped section; so as to present little obstruction to the
lateral radiation of the light; or in some cases it may bo widened out and faced so
as to form a reflector. The heat conducted downwards as above described may bo
in part applied to generate the gas. One method for effecting this is to provide in
the lower part of the lamp a vessel containing petroleum or other volatile oil. Air
being admitted in regulated quantity to this. vessel will take up inflammable vapour,
and the mixture will constituto the combustible gas supplying the flame.

page_text: the disc C within a casing D of material, such as asbestos or ceramic material,
which is a bad conductor of heat. Above the discs C I fix a deflecting cone E of
ordinary form for directing the air against the root of the flame. The lamp being
supplied with gas at B³ operates as follows:-The stem B and its crown B' become
highly heated by the flame surrounding B, and a large portion of the heat is con-
ducted downwards to the perforated discs C, so that the air passing through their
perforations becomes heated, and this heated air supplying the flame, partly outside
as directed by the cone E, and partly inside, as indicated by the arrows at Fig. 2,
causes the gas to burn with great brilliancy.
Instead of supplying the gas directly to the stem at B³, the prolongation B³ of,
the stem may be made with lateral perforations to extend down, as shown, into a
vessel F containing solid or liquid hydrocarbon, such as naphthaline or heavy oil,
with which the vessel can from time to time be charged by a lateral aperture
covered by a screw cap G. The gas being in this case supplied by a pipe H will
become enriched by the admixture with it of bydrocarbon vapour generated by
the heat conducted along the extended stem B³.
By employing a more volatile hydrocarbon in the vessel F, gas may be altogether
dispensed with. For this purposo the pipe H or a lateral pipe K may be supplied
with air at a moderate pressure, somewhat above that of the atmosphere, and this
air in passing through the vessel F becomes charged with hydrocarbon vapour, so
that the mixture burns as gas. When the lamp is used in this manner it is
necessary in the first place to heat the contents of F, which may be done by
applying external heat. The burner A may be of oblong instead of circular form,
in which case, if its width is considerable, two or more heat conducting stems
instead of only one may be employed.
Fig. 5 shews a vertical section, and Fig. 6 a cross section on line X, X, of another
arrangement in which the crown B' of the stem B is formed of cup shape, and
filled with a mass B of fire clay or other suitable refractory material, so that the
combined mass in becoming very highly heated by the flame serves both to effect
a more completo combustion of the gas and to add to the luminous effect of the
flame.
The burner A is in this case surrounded by a cage consisting of ribbed bars M
fixed to a perforated disc N, round which are wound several coils of wire gauze O,
secured externally by metal rings. From the lower end of the rod B branches B¹
are made to extend to the surrounding cage, so as to conduct heat from the former
to the latter, a further quantity of heat being conveyed through the disc N, which
may conveniently be formed in one casting with the gas pipe B and base A' of
the burner, into which the rod B is screwed. Between the disc N and a second
perforated disc N¹ are secured several layers of wire gauzo O¹, which also become
considerably heated, so that the air in passing through these and also through the
wire gauze casing O on its way to the burner becomes heated, as before described,
and is directed by the cone E against the flame.
Fig. 7 shews a vertical section of a bats-wing burner with my Invention applied
thereto. The burner A is surrounded by a wire gauze casing O forined, as described,
with reference to the last arrangement, upon which is fixed the cone E carrying
the bent metal rod B, so formed as to present considerable surface to the bat's-
wing flame. The heat thus taken up by the rod being conducted through the
cone E to the wire casing O, the air passing through the latter to the burner.
becomes heated, as before. The lower end of the casing is in this case closed by a
solid disc N fixed or formed on the gas pipe A, and serving to support the casing O
and rod B.
Having thus described the nature of my Invention, and in what manner the
same is to be performed, I claim in respect of gas lamps,-
First. The use of a stem or stems inade of metal which is a good conductor of
heat, exposed at the upper part to the heat of the flame and products of combus-
tion, in combination with extended metallic surfaces at the lower part heated by
conduction through tho stem, so that air on its way to supply the flame is heated

page_text: in passing these heated surfaces, substantially as and for the purpose herein set
forth.
Second. In a gas lamp with heat conducting stem or stems, referred to in the
preceding claim, coating the said stem or stems with a refractory substance capable
of radiating light, and protecting the stem from deterioration by the flame,
substantially as herein described.
Third. In combination with heat conducting stems, such as are referred to in the
preceding claims, the use of a lump or enlargement on the upper end of the stem,
which, in becoming highly heated, serves both to produce more complete
combustion, and to add to the luminous effect of the flame, substantially as herein
described.
In witness whereof, I, the said Charles William Siemens, have hereunto set
my hand and seal, this Ninth day of May, in the year of our Lord One
thousand eight hundred and eighty oue.