IMPROVEMENTS IN LAMPS AND IN LANTERNS THEREFOR
Year: 1880

page_text: LETTERS PATENT to Frederick Siemens, of Dresden, in the Kingdom of
Saxony, but at present of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex, for an Invention of "IMPROVEMENTS IN LAMPS
AND IN LANTERNS THEREFOR."
PROVISIONAL SPECIFICATION left by the said Frederick Siemens at the
Office of the Commissioners of Patents on the 10th December 1880.
FREDERICK SIEMENS, of Dresden, in the Kingdom of Saxony, but at present of
No. 28, Southampton Buildings, Chancery Lane, in the County of Middlesex.
"IMPROVEMENTS IN LAMPS AND IN LANTERNS THEREFOR."
My Invention has reference to a construction of gas lamps wherein the heat of
the products of combustion is imparted more or less to the air and gas supply for
the frame. I have described various constructions of such lamps in the Specifi-
cations to Letters Patent granted to me bearing date the 5th June, 1879, No. 2231,
and the 16th April, 1880, No. 1561.
According to one part of my present Invention I adapt such lamps for use in the
open air by enclosing them entirely within a lantern of the following arrange-
ment -The body of the lantern may be of any desired configuration, but by
preference I make it of two glass conical frustra fitted with their large ends in a
metal ring, the lower cone being inverted. The upper cone, which is of some
height, has a chimney attached to its upper end covered by a cowl, while the lower
cone also has a metal cylinder attached to it extending down some distance, and
closed at its lower end by a perforated or wire gauze diaphragm which may be of
conical shape. Within the lantern, its lower end extending some distance down
within the last named metal cylinder, is the lamp, which may be of the construction
described at Figs. 1 to 5 in the Specification of my beforementioned Patent,
No. 1561, of 1880, the chimney of the lamp extending up into the chimney of the
lantern but stopping short of the top thereof. Thus the bottom cylinder of the
lantern being heated by the lower part of the lamp, a hot column of air is produced
therein, inducing an upward current of air sufficient for the air supply of the lamp
and for effecting the perfect ventilation of the lantern, so that the products of
Din 21

page_text: combustion that issue from the chimney of the lamp into that of the lantern, will
be effectually carried off from the latter. At the same time the lamp is so protected
by the lantern against external currents of air that the flame will burn steadily
without a glass.
According to another improvement I construct such before mentioned lamps,
whether employed in combination with the lantern or otherwise, as follows:-
Instead of causing the products of combustion from the flame to pass right down
through the central chamber of the lamp so as to issue at the lower part thereof into
a pipe leading up to a chimney above the flame, as described in my said previous
Specification, I continue the chimney downwards to some distance within the said
chamber, leaving an annular space between the two, so that the products of
combustion pass downwards in the said chamber until they reach the lower opening
of the chimney, up which they then escape after imparting a great portion of their
heat to the walls of the chamber and lower end of the chimney, such heat being
conveyed by conduction and radiation to the annular air chamber surrounding the
central chamber. The lower end of the latter, which together with the air
chamber is continued down some distance below the burner, may either be quite
closed or it may have openings through which a certain quantity of air can enter,
so that this air in meeting the highly heated products of combustion as they pass
downwards to enter the chimney will enter into combustion with any particles
of unburnt gas that may escape from the burner, thereby producing additional
heat.
The lower part of the chimney is by preference formed of some good heat
resisting material, such as fireclay or porcelain.
The annular air chamber is by preference divided into two compartments by an
annular partition, the inner annular space serving as the heating chamber for the
main air supply to the flame against which it is made to impinge at top by a
notched air deflector, such as described in my beforementioned previous Patents,
while the air current passing up through the outer annular space serves mainly to
steady the flame by the draught produced thereby.
When this construction of burner is employed in combination with the before-
described construction of lantern, a further annular space is formed between the
outside of the second air space of the lamp and the sides of the metal cylinder
forming the bottom of the lantern, through which space the current of air passes
for ventilating the interior of the lantern.
The above described construction of double annular air chamber to the lamp
may also be used in combination with the arrangement of the central chamber
for the products of combustion described in my previous Specification, in which
they are led from the bottom of such chamber through a lateral pipe into the
chimney above.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frederick Siemens in the Great Seal Patent Office on the 7th June
1881.
FREDERICK SIEMENS, of Dresden, in the Kingdom of Saxony, but at present of
No. 28, Southampton Buildings, Chancery Lane, in the County of Middlesex.
IMPROVEMENTS IN LAMPS AND IN LANTERNS THEREFOR."
My Invention has reference to a construction of gas lamps wherein the heat of
the products of combustion is imparted more or less to the air and gas supply for
the flame. I have described various constructions of such lamps in the Specifications
to Letters Patent granted to me bearing date the 5th June 1879, No. 2231, and
the 16th April 1880, No. 1561.
According to one part of my present Invention I adapt such lamps for use in the
open air by enclosing them entirely within a lantern of the following arrange-
ment: The body of the lantern may be of any desired configuration, but by
preference I make it of two glass conical frusta fitted with their large ends in a
metal ring, the lower cone being inverted. The upper cone which is of some height
has a chimney attached to its upper end covered by a cowl, while the lower cone
also has a metal cylinder attached to it extending down some distance, and closed
at its lower end by a perforated or wire gauze diaphragm which may be of conical
shape. Within the lantern, its lower end extending some distance down within
the last named metal cylinder, is the lamp, which may be of the construction
described at Figs. 1 to 5 in the Specification of my before mentioned Patent,
No. 1561 of 1880, the chimney of the lamp extending up into the chimney of the
lantern but stopping short of the top thereof. Thus the bottom cylinder of the
lantern being heated by the lower part of the lamp, a hot column of air is produced
therein, inducing an upward current of air sufficient for the air supply of the lamp
and for effecting the perfect ventilation of the lantern, so that the products of
combustion that issue from the chimney of the lamp into that of the lantern will
be effectually carried off from the latter. At the same time the lamp is so protected
by the lantern against external currents of air that the flame will burn steadily
without a glass.
According to another improvement I construct such before mentioned lamps,
whether employed in combination with the lantern or otherwise, as shewn on the
accompanying Drawing.
In the construction of lamp shewn in vertical section at Fig. 1, the burner,
consisting of the gas chamber a, with tubes c, with central chamber b, through
which the products of combustion from the flame- pass downwards, and with an
outer chamber e through which the air supply passes upwards, are similar in their
general arrangement to the lamp described in my former Patents referred to above,
as are also the fireclay or porcelain cylinder k which determines the height of the
flame, and the notched air deflector g; the principal modifications consist, firstly,
in enlarging the gas chamber a, and causing the passage i for the products of
combustion to pass through it, whereby the heat thereof will be more effectually
taken up by the gas; secondly, in extending the air chamber e downwards, so as
by the heat imparted by conduction to its sides, to produce a column of heated air
within it sufficient to supply a current of the requisite intensity to enable the flame
to burn effectually without the ordinary chimney draught above it; thirdly, in
dispensing with the ordinary chimney glass and allowing the upward draught from
the flame to communicate direct with the chimney through a small opening i³,
the chimney 2, together with the pipe ¹ connecting it with the passage i, being
¿ ³

page_text: formed of comparatively large diameter, so that notwithstanding the direct
communication between the flame and i2, the greater part of the products of
combustion will still be drawn down through the chamber i, when the pipe "
becomes heated. If desired a slide or throttle valve. may be provided in the
opening to close it more or less when the draught up i has once been
established; fourthly, in providing outside the chamber e a second narrow annular
passage e¹, through which a current of air also passes, so as to take up heat that
would otherwise be lost by radiation from the casing of e, which current
in impinging against the outer surface of the flame serves to steady it. A
glass guarde may surround the flame in order still further to increase its
steadiness.
The chambers 6 and e are here shewn without the filling of perforated cones or
plates for assisting in taking up the heat from the products of combustion and
imparting the same to the air current as described in the Specifications of my
former Patents above referred to, but if desired such filling of plates or wire
gauze may also be used with this construction.
The above described construction of lamp is enclosed with its chimney entirely
within a lantern for open air illumination, as herein before described, the arrange-
ment being such that the burner is effectually protected against the action of
external air currents. The lantern is for this purpose constructed of two glass
frusta A, B, of which the upper one is by preference more or less opaque while the
lower one is transparent. The part A is by preference of some height, and termi-
nates in a chimney C covered with a cowl C, within which is the chimney i² of
the burner. The lower cone B terminates in a metal extension D closed near its
lower end by a wire gauze or perforated diaphragm D¹, and surrounded by a
casing E closed at bottom and open at top, so that the air entering the lantern has
first to pass down through the annular space between E and D and then to rise up
through the diaphragm D' and tube D before arriving at the burner. The lower
end of the latter extends down into D, and by means of the heat radiated therefrom
produces a column of heated air therein sufficient to produce the requisite draught
for the air supply of the lamp, and for effecting the perfect ventilation of the
lantern, so that the products of combustion issuing into the chimney of the lantern
from that of the lamp are effectually carried off.
Fig. 2 shews a part vertical section and part elevation of another modification
of the burner, in which the products of combustion from the flame are not carried
off from the bottom of the chamber b as in the previous arrangements, but in lieu
thereof the chimney has a downward extension i made of fireclay, porcelain, or
other heat resisting material, extended to some distance down into the chamber b,
so that the flame and products of combustion first pass down into such chamber, as
in the previous arrangements, and then rise up and escape through the chimney i, i².
The heat imparted to the extension i is conveyed by radiation to the burner tubes c
and air chamber e. In this case the bottom of the chamber b may either be entirely
closed or it may have one or more small apertures for the admission of a small
quantity of air for entering into combustion with any particles of combustible gas
that may escape from the burner without being burnt at that point. By this means
additional heat would be imparted to the chamber b.
The lantern A, B, is similar in construction to that above described, the outer
casing Ę being dispensed with.
Although I have shewn the construction of burners at Figs. 1 and 2 in combi-
nation with the lanterns, it is to be understood that they may also be used apart
from such combination.
Having thus described the nature of my Invention, and in what manner the
same is to be performed, I claim,―
First. The improved construction of lamp herein described with reference to
Fig. 1 of the Drawings.
Second. The construction of lamps wherein the chimney is extended downwards

page_text: into a central chamber within the burner, so that the products of combustion have
first to pass down into such chamber in order to escape thence up the chimney,
substantially as herein described with reference to Fig. 2 of the Drawings.
Third. The construction of lamps wherein the air supply is caused to ascend
through two concentric annular passages, substantially as and for the purposes
herein described with reference to Figs. 1 and 2 of the Drawings.
Fourth. The construction of lantern arranged in combination with a lamp, sub-
stantially as herein described with reference to Figs. 1 and 2 of the Drawings, the
upper end of the lantern being provided with a chimney enclosing the chimney of
the lamp, while the lower end has a downward extension into which projects the
lower end of the lamp, so as to impart heat to the air ascending therein.
In witness whereof, I, the said Frederick Siemens have hereunto set my
hand and seal, this First day of June, in the year of our Lord One thousand
eight hundred and eighty one.
FREDERICK SIEMENS. (L.S.)