Improvements relating to Lamps or Lighting Apparatus for Railway and other Purposes.
Year: 1887

page_text: This Specification was, upon the 21st day of July 1888, amended under
Sections 18 to 21 of the Patents, Designs, and Trade Marks Act, 1883.
Improvements relating to Lamps or Lighting Apparatus for
Railway and other Purposes.
We, JAMES THORNE, Merchant, and EBENEZER BANTON BURR, Engineer, both of
85 Gracechurch Street, in the City of London, do hereby declare the nature of this
invention to be as follows :-
"
27
The main object of our invention is to provide an electric "head-lamp," "tail-lamp,"
side-lamp or other signal-lamp for railway purposes, which will be complete in
itself, having no external wires or connections. Our improvements are, however,
applicable to mast-head lamps or other signal-lamps for ships, to lamps for omnibuses,
tramway-cars, cabs, velocipedes and other vehicles, to miner's lamps and to lamps for
telegraphing by means of "flashing" signals, or for other purposes.
Our said invention comprises improvements whereby we provide for greatly
increasing the illuminating power of our lamp as compared with lamps heretofore used
for similar purposes.
One feature of our said invention is the combination, with a lantern or lamp-casing,
of an electric incandescence lamp, an electric battery and a reflector all arranged
within the said lantern or casing, so that no external wires or connections are required,
and the lamp can be readily inserted in, or removed from, its place on a vehicle or
other object, without the necessity for connecting or disconnecting any wires. More-
over, as there is no need for ventilation, the said lantern or lamp-casing can be made
without a chimney or ventilator, and can be closed (hermetically, if desired) so as to
exclude dust.
Another feature of our said invention is the combination, with a parabolic, elliptic
or other reflector, of a lens or "bull's eye" having a corresponding form, the said

page_text: reflector and lens being so arranged relatively to each other that we are enabled to
place the light and the reflector much nearer the lens than heretofore and thus leave
space within the lantern or casing for the electric battery, without the necessity for
increasing the size of the lantern or casing as compared with those ordinarily used for
similar purposes. Moreover, we make the reflector and the lens of such relative
shape or configuration, and so adjust their position relatively to each other that we
obtain the best practicable results in respect of the intensity of the light. This feature
of our said invention is applicable to various kinds of lamps.
Our said invention is conveniently and advantageously carried into practice as
hereinafter described, that is to say, we provide a suitable lantern or lamp-casing
provided with a lens or "bull's eye" and a parabolic or other reflector which is made
with a socket adapted to fit upon a bracket formed on, or attached to, a sliding plate.
We also provide an electric battery or accumulator, which is placed upon and, if
necessary, attached to the said plate, and an electric incandescence lamp of any suitable
description, which is suspended from wires passed through a tube or socket fixed in
the reflector, the said wires being secured in the said socket by means of a set-screw
or otherwise. The said plate is fitted to slide between guides formed on, or attached
to, the lantern or casing, so that the battery, the lamp and the reflector can be very
readily inserted in. and removed from, the said casing.
To provide for tightly closing the battery and, at the same time, firmly securing it
in the casing and preventing its withdrawal except by an authorized person, we employ
a screw which is passed through a tapped hole in a socket secured to the casing. The
lower end of this screw bears against the lid of the battery and holds the same down
so that the battery is kept tightly closed. The upper end of the said screw is made
square or of other suitable shape so that a key may be fitted thereon to permit the
turning of the said screw. The said key is so made that it will fit into the hole or
cavity in the said socket, which hole or cavity may be of any desired shape.
When a primary battery is employed, we prefer to use that described in the Speci-
fication of former Letters Patent dated 2nd September A.D. 1882, No. 4198.
We
may, however, use any other suitable primary battery, or we may use a secondary
battery or accumulator.
Instead of
The lens is secured in the casing in any well-known or suitable manner.
making the lens of the ordinary spherical form, we prefer to make it of approximately
the form of a parabaloid, and to use a parabolic reflector. Whatever may be the
shape of the reflector used, we employ a lens of corresponding shape and so adjust
the reflector relatively to the lens that their foci will correspond or coincide, so that
the rays of light concentrated by the reflector will pass through the lens and extend
therefrom in a direction parallel, or nearly parallel, to its axis.
By the use of a parabolic lens and reflector arranged in this manner and suitably
proportioned, we are enabled to obtain a light of about two hundred candle-power
from an incandescence lamp which would otherwise give only five candle-power.
25
In a side-lamp for a railway-train, or in any similar lamp, we employ two lenses
and a double reflector, that is to say, portions of two parabolic or other reflectors
united so as to form a tubular reflector, and we place the electric incandescence lamp in
the centre.
When used for railway purposes, our improved lamp affords, amongst others, the
following advantages, viz. :-There are no external wires or connections, therefore
the lamp can be readily transferred from one vehicle to another, and no disconnection
of wires is necessary when slipping a carriage. There is no need of ventilation,
therefore the casing can be made without a chimney or ventilator and can be tightly
closed so as to exclude dust. No trimming is required, and there is no smoke, grease
or soot to dim the lens and obscure the light. The light cannot be affected by air
currents or eddies produced by the motion of the train or otherwise. There is no
risk of fire in case of breakage of the lamp in a collision or other accident. The
lamp can be easily handled, and the battery can be very readily withdrawn, recharged
and replaced.
We sometimes provide interchangeable slides of green or other colored glass which

page_text: can be very readily inserted in, and withdrawn from, the lantern or lamp-casing to
determine the color of the light. For railway purposes, our lamp has the further
advantage that these slides can be changed without liability to extinction of the light
when the door of the casing is opened. The necessity for any mechanical devices for
changing them without opening the lamp is thus obviated.
We do not confine ourselves to any special form or arrangement of the parts of our
improved lamp, as these will depend to a great extent upon the purpose for which the
lamp is required, and can be considerably modified without departing from the nature
of our invention.
Dated this 12th day of February 1887.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicants.

page_text: COMITEIT DI MULETUATION (S MEN DET).
Improvements relating to Lamps or Lighting Apparatus for
Railway and other Purposes.
We, JAMES THORNE, Merchant, and EBENEZER BANTON BURR, Engineer, both of
85 Gracechurch Street, in the City of London do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :—
Our invention relates to electric lamps or lighting apparatus provided as herein-
after described with lenses and reflectors that will concentrate rays of light in a better
manner than lamps of ordinary construction.
» (
29
The main object of our said invention is to provide an electric " head-lamp
tail-lamp, side-lamp or other signal-lamp for railway purposes, which will be
complete in itself, having no external wires or connections.
Our improvements are, however, applicable to mast-head lamps or other signal-
lamps for ships, to lamps for omnibuses, tramway-cars, cabs, velocipedes or other
vehicles, and also to lamps for telegraphing by means of "flashing" signals, or for
mining or other purposes.
One feature of our said invention is the combination, with a lantern or lamp-easing,
in the manner herein described of an electric incandescence lamp, an electric battery or
accumulator, a lens of the kind hereinafter mentioned and a reflector, all arranged in
the said lantern or casing, so that the apparatus can be readily inserted in, or
removed from, its place on a vehicle or other object, without the necessity for
connecting or disconnecting any wires. Moreover as there is no need for ventilation,
the said lantern or lamp-casing can be made without a chimney or ventilator and
can be closed (hermetically, if desired) so as to exclude dust.
We use a parabolic, elliptic or other reflector or approximately parabolic or elliptic
or approximately elliptic reflector and a lens or bull's-eye" having a corresponding
approximately parabolic or elliptic form, and we arrange the said reflector and lens
relatively to each other in the manner described in the provisional specification filed
with our application for Letters Patent dated 13th May A.D. 1887, No. 7046, that
is to say, so that their foci will correspond or coincide with each other being situated
in the axial line common to both lens and reflector and the rays of light concentrated
by the reflector will therefore pass through the lens and extend therefrom in the form
of a parallel beam or nearly so. By this arrangement of the lens and reflector, we are
enabled to place the light and the reflector much nearer the lens than heretofore and
thus leave space within the lantern or casing for the electric battery without the
necessity for increasing the size of the lantern or casing as compared with those
ordinarily used for similar purposes; moreover, we obtain the best practicable
results in respect of the intensity of the light passed through the lens.
Our said invention comprises other improvements hereinafter set forth.
In the accompanying drawings-
Figure 1 is a vertical longitudinal central section of one form of our improved
apparatus.

page_text: Figure 2 is a transverse section on the line a, a, Figure 1.
Figure 3 is a vertical transverse central section of another form or modification of
our said apparatus, and
Figure 4 is a vertical longitudinal section on the line a, a, Figure 3.
Like letters indicate corresponding parts throughout the drawings.
a is the lantern or lamp-casing, is the lens or
"bull's-eye
which is secured
therein in any well-known or suitable manner. c is a parabolic reflector, which is
made with a socket c¹ adapted to fit upon a bracket & formed on, or attached to, a
sliding plate d.
e is the battery, which is placed upon and, if necessary, attached to the said sliding
plate. is an electric incandescence lamp of any suitable description, which is
suspended from wires passed through a block or piece of insulating material inserted in
a tube or socket c² fixed in the reflector c, the said block or piece being secured in the
socket by means of a set-screw c³. The plate d is fitted between guides a¹ formed on,
or attached to the casing a, so that the said plate with the battery, the lamp and the
reflector can be very readily inserted in, and removed from the said casing.
To provide for tightly closing the battery and, at the same time, firmly securing it
in the casing and preventing its wiihdrawal except by an authorised person, we
employ a screw which is passed through a tapped hole in a socket gl secured to the
casing a. The lower end of this screw bears against the lid e¹ of the battery and
holds the same down so that the battery is kept tightly closed, a sheet or washer of
india-rubber or other elastic material being preferably placed between the lid and
body of the said battery to ensure tightness of the joint. The upper end of the
screw is made square or of other suitable shape so that a key may be fitted thereon
to permit the turning of the said screw in either direction. The said key is so made
that it will fit into the hole or cavity in the socket g, which hole or cavity may be
of any desired shape.
We
When a primary battery is employed, we prefer to use that described in the specifi-
cation of former Letters Patent dated 2nd September A.D. 1882, No. 4198.
may, however, use any other suitable primary battery, or we may use a secondary
battery or accumulator.
is a switch for completing or interrupting the electric circuit, for the purpose of
putting the apparatus into or out of action when desired.
We sometimes arrange, in combination with this switch, a clockwork device for
indicating the length of time during which the lamp has been alight, so that the state
of the battery may be readily ascertained at any time. This device is so connected
with the switch that, when the light is turned off, the movement of the clockwork will
be arrested. Or, we use an indicator which may be adjusted by hand for the purpose
above specified.
Instead of making the lens of the ordinary spherical form, we prefer to make it in
the form of a paraboloid, for example above mentioned being of an approximately
parabolic or elliptic form as shewn in the drawing, and to we use a parabolic corre-
sponding reflector. Whatever may be the shape of the reflector used, it is advan-
tageous to employ a lens of corresponding shape and to so-adjust the reflector
relatively to the lens that their foci will correspond or coincide as described in the
aforesaid provisional specification.
25
"
The lamp or apparatus shown in Figures 1 and 2 will serve very efficiently as a
"head lamp
or tail lamp for use on a railway carriage or locomotive.
The lamp shewn in Figures 3 and 4 is designed as a
side lamp for a railway
carriage. It has two lenses and a double reflector, that is to say, two parabolic
reflectors e portions of which are cut off through a plane perpendicular to their axes
and which are united at c, the electric incandescence lamp being placed in the
centre as shown.
When used for railway purposes, our improved lamp affords, amongst others, the
following advantages, viz. :-There are no external wires or connections, therefore the
lamp can be readily transferred from one vehicle to another, and no disconnection
of wires is necessary when slipping a carriage. There is no need of ventilation

page_text: therefore the casing can be made without a chimney or ventilator and can be tightly
closed so as to exclude dust. No trimming is required as in oil-lamps, and there is no
smoke, grease or soot to dim the lens and obscure the light. The light cannot be
affected or extinguished as in oil-lamps by air currents or eddies produced by the
motion of the train or otherwise. There is no risk of fire in case of breakage of the
Imp in a collision or other accident. The lamp can be easily handled and the battery
can be very readily withdrawn, recharged and replaced.
We sometimes provide interchangeable slides of green or other colored glass (as
shewn, for example, at i in Figure 1) which can be very readily inserted in, and with-
drawn from the lantern or lamp-casing for the purpose of changing or determining
the color of the light. For railway purposes, our lamp has the further advantage that
these slides can be changed without liability to extinction of the light when the door
of the casing is opened; the necessity for any mechanical devices for changing them
without opening the said casing is thus obviated.
We do not confine ourselves save as regards lens and reflector to any special form
or construction of the parts of our improved lamp, as these will depend to a great
extent upon the purpose for which the lamp required, and can be considerably
modified without departing from the nature of our invention.
"
It is evident that our improved apparatus may be adapted for telegraphing by means
of "flashing
signals, by providing it with a movable shutter or dise for obscuring
the light when necessary.
Having now particularly described and ascertained the nature of our said invention
and in what manner the same is to be performed, we wish it understood that, in our
present application for Letters Patent, we make no claim per se for the employment
of a parabolic lens, apart from its use in an electric lamp nor do we make any claim
irrespectively of our other improvements herein-set forth, for the use, in combination
with a parabolic lens, of a parabolic reflector as, and for the purpose, above specified,
irrespectively of their use in an electric lamp and of our other improvements herein
set forth, as the use of such lenses and reflectors forms the subject of our other appli-
cutions for Letters Patent No. 7046 of 1887, and No. 631 of 1888; but we claim :-
First. The combination, with a lantern or lamp-casing, of an electric lamp, a lens
and reflector of parabolic or other-form, such as are hereinbefore described and an
electric battery or accumulator, all substantially as, and for the purposes, above
specified.
Second. The improved-means;-substantially as set forth, whereby we provide-for
simultaneously closing the battery and securing it within the lantern of ensing as
above specified.
Third Second. The improved lamp or lighting apparatus provided with a lens and
reflector such as are herein mentioned and consisting of the parts constructed and
combined substantially as described with reference to Figures 1 and 2 or to Figures 3
nd 4 of the drawings for the purposes specified.
al
Dated this 10th day of December 1887.
Dated this 10th day of December 1887.
JAMES THORNE.
E. B. BURR.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.

page_text: Date of Application, 12th Feb., 1887.
Complete Left, 12th Dec., 1887
Complete Accepted, 3rd Feb, 1888.
Improvements relating to Lamps or Lighting Apparatus for
Railway and other Purposes.
We, JAMES THORNE, Merchant, and EBENEZER BANTON BURR, Engineer, both of
85 Gracechurch Street, in the City of London, do hereby declare the nature of this
invention to be as follows:-
The main object of our invention is to provide an electric "head-lamp," "tail-lamp,"
side-lamp" or other signal-lamp for railway purposes, which will be complete in
itself, having no external wires or connections. Our improvements are, however,
applicable to mast-head lamps or other signal-lamps for ships, to lamps for omnibuses,
tramway-cars, cabs, velocipedes and other vehicles, to miner's lamps and to lamps for
telegraphing by means of "flashing" signals, or for other purposes.
Our said invention comprises improvements whereby we provide for greatly
increasing the illuminating power of our lamp as compared with lamps heretofore used
for similar purposes.
One feature of our said invention is the combination, with a lantern or lamp-casing,
of an electric incandescence lamp, an electric battery and a reflector all arranged
within the said lantern or casing, so that no external wires or connections are required,
and the lamp can be readily inserted in, or removed from, its place on a vehicle or
other object, without the necessity for connecting or disconnecting any wires. More-
over, as there is no need for ventilation, the said lantern or lamp-casing can be made
without a chimney or ventilator, and can be closed (hermetically, if desired) so as to
exclude dust.
Another feature of our said invention is the combination, with a parabolic, elliptic
or other reflector, of a lens or "bull's eye" having a corresponding form, the said

page_text: reflector and lens being so arranged relatively to each other that we are enabled to
place the light and the reflector much nearer the lens than heretofore and thus leave
space within the lantern or casing for the electric battery, without the necessity for
increasing the size of the lantern or casing as compared with those ordinarily used for
similar purposes. Moreover, we make the reflector and the lens of such relative
shape or configuration, and so adjust their position relatively to each other that we
obtain the best practicable results in respect of the intensity of the light. This feature
of our said invention is applicable to various kinds of lamps.
Our said invention is conveniently and advantageously carried into practice as
hereinafter described, that is to say, we provide a suitable lantern or lamp-casing
provided with a lens or
bull's eye,
and a parabolic or other reflector which is made
with a socket adapted to fit upon a bracket formed on, or attached to, a sliding plate.
We also provide an electric battery or accumulator, which is placed upon and, if
necessary, attached to the said plate, and an electric incandescence lamp of any suitable
description, which is suspended from wires passed through a tube or socket fixed in
the reflector, the said wires being secured in the said socket by means of a set-screw
or otherwise. The said plate is fitted to slide between guides formned on, or attached
to, the lantern or casing, so that the battery, the lamp and the reflector can be very
readily inserted in, and removed from, the said casing.
To provide for tightly closing the battery and, at the same time, firmly securing it
in the casing and preventing its withdrawal except by an authorized person, we employ
a screw which is passed through a tapped hole in a socket secured to the casing. The
lower end of this screw bears against the lid of the battery and holds the same down
so that the battery is kept tightly closed. The upper end of the said screw is made
square or of other suitable shape so that a key may be fitted thereon to permit the
turning of the said screw. The said key is so made that it will fit into the hole or
cavity in the said socket, which hole or cavity may be of any desired shape.
When a primary battery is employed, we prefer to use that described in the Speci-
'fication of former Letters Patent dated 2nd September A.D. 1882, No. 4198. We
may, however, use any other suitable primary battery, or we may use a secondary
battery or accumulator.
Instead of
The lens is secured in the casing in any well-known or suitable manner.
making the lens of the ordinary spherical form, we prefer to make it of approximately
the form of a parabaloid, and to use a parabolic reflector. Whatever may be the
shape of the reflector used, we employ a lens of corresponding shape and so adjust
the reflector relatively to the lens that their foci will correspond or coincide, so that
the rays of light concentrated by the reflector will pass through the lens and extend
therefrom in a direction parallel, or nearly parallel, to its axis.
By the use of a parabolic lens and reflector arranged in this manner and suitably
proportioned, we are enabled to obtain a light of about two hundred candle-power
from an incandescence lamp which would otherwise give only five candle-power.
In a "side-lamp" for a railway-train, or in any similar lamp, we employ two lenses
and a double reflector, that is to say, portions of two parabolic or other reflectors
united so as to form a tubular reflector, and we place the electric incandescence lamp in
the centre.
When used for railway purposes, our improved lamp affords, amongst others, the
following advantages, viz. :-There are no external wires or connections, therefore
the lamp can be readily transferred from one vehicle to another, and no disconnection
of wires is necessary when slipping a carriage. There is no need of ventilation,
therefore the casing can be made without a chimney or ventilator and can be tightly
closed so as to exclude dust. No trimming is required, and there is no smoke, grease
or seot to dim the lens and obscure the light. The light cannot be affected by air
currents or eddies produced by the motion of the train or otherwise. There is no
risk of fire in case of breakage of the lamp in a collision or other accident.
lamp can be easily handled, and the battery can be very readily withdrawn, recharged
and replaced.
The
We sometimes provide interchangeable slides of green or other colored glass which

page_text: can be very readily inserted in, and withdrawn from, the lantern or lamp-casing to
determine the color of the light. For railway purposes, our lamp has the further
advantage that these slides can be changed without liability to extinction of the light
when the door of the casing is opened. The necessity for any mechanical devices for
changing them without opening the lamp is thus obviated.
We do not confine ourselves to any special form or arrangement of the parts of our
improved lamp, as these will depend to a great extent upon the purpose for which the
lamp is required, and can be considerably modified without departing from the nature
of our invention.
Dated this 19th day of Fahr 1987
HASELTINE, LAKE & Co.,
. 45, Southampton Buildings, London,
Agents for the Applicants.

page_text: Kailway and other Furposes.
We, JAMES THORNE, Merchant, and EBENEZER BANTON BURR, Engineer, both of
85 Gracechurch Street, in the City of London do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
Our invention relates to electric lamps or lighting apparatus.
33
The main object of our said invention is to provide an electric “ head-lamp"
"tail-lamp," "side-lamp or other signal-lamp for railway purposes, which will be
complete in itself, having no external wires or connections.
Our improvements are, however, applicable to mast-head lamps or other signal-
lamps for ships, to lamps for omnibuses, tramway-cars, cabs, velocipedes or other
vehicles, and also to lamps for telegraphing by means of "flashing" signals, or for
mining or other purposes.
One feature of our said invention is the combination, with a lantern or lamp-casing,
of an electric incandescence lamp, an electric battery or accumulator, a lens and a
reflector, all arranged in the said lantern or casing, so that the apparatus can be readily
inserted in, or removed from, its place on a vehicle or other object, without the
necessity for connecting or disconnecting any wires. Moreover as there is no need for
ventilation, the said lantern or lamp-casing can be made without a chimney or
ventilator and can be closed (hermetically, if desired) so as to exclude dust.
We use a parabolic, elliptic or other reflector and a lens or "bull's-eye" having a
corresponding form, and we arrange the said reflector and lens relatively to each
other in the manner described in the provisional specification filed with our application
for Letters Patent dated 13th May A.D. 1887, No. 7046, that is to say, so that their
foci will correspond or coincide with each other and the rays of light concentrated by
the reflector will pass through the lens and extend therefrom in the form of a parallel
beam or nearly so. By this arrangement of the lens and reflector, we are enabled to
place the light and the reflector much nearer the lens than heretofore and thus leave
space within the lantern or casing for the electric battery without the necessity
for increasing the size of the lantern or casing as compared with those ordinarily
used for similar purposes; moreover, we obtain the best practicable results in respect
of the intensity of the light.
Our said invention comprises other improvements hereinafter set forth.
In the accompanying drawings-
Figure 1 is a vertical longitudinal central section of one form of our improved
apparatus.

page_text: Figure 2 is a transverse section on the line x, a, Figure 1.
Figure 3 is a vertical transverse central section of another form or modification of
our said apparatus, and
Figure 4 is a vertical longitudinal section on the line a, e, Figure 3.
Like letters indicate corresponding parts throughout the drawings.
a is the lantern or lamp-casing, 6 is the lens or "bull's eye
"which is secured
therein in any well-known or suitable manner. c is a parabolic reflector, which is
made with a socket c adapted to fit upon a bracket d¹ formed on, or attached to, a
sliding plate d.
e is the battery, which is placed upon and, if necessary, attached to the said sliding
plate. is an electric incandescence lamp of any suitable description, which is
suspended from wires passed through a block or piece of insulating material inserted in
a tube or socket c² fixed in the reflector c, the said block or piece being secured in the
socket by means of a set-screw c³. The plate d is fitted between guides a¹ formed on,
or attached to the casing a, so that the said plate with the battery, the lamp and the
reflector can be very readily inserted in, and removed from the said casing.
To provide for tightly closing the battery and, at the same time, firmly securing it
in the casing and preventing its withdrawal except by an authorised person, we
employ a screw g which is passed through a tapped hole in a socket g¹ secured to the
casing a. The lower end of this screw bears against the lid e¹ of the battery and
holds the same down so that the battery is kept tightly closed, a sheet or washer of
india-rubber or other elastic material being preferably placed between the lid and
body of the said battery to ensure tightness of the joint. The upper end of the
screw is made square or of other suitable shape so that a key may be fitted thereon
to permit the turning of the said screw in either direction. The said key is so made
that it will fit into the hole or cavity g² in the socket g, which hole or cavity may be
of any desired shape.
When a primary battery is employed, we prefer to use that described in the specifi-
cation of former Letters Patent dated 2nd September A.D. 1882, No. 4198. We
may, however, use any other suitable primary battery, or we may use a secondary
battery or accumulator.
A is a switch for completing or interrupting the electric circuit, for the purpose of
putting the apparatus into or out of action when desired.
We sometimes arrange, in combination with this switch, a clockwork device for
indicating the length of time during which the lamp has been alight, so that the state
of the battery may be readily ascertained at any time. This device is so connected
with the switch that, when the light is turned off, the movement of the clockwork will
be arrested. Or, we use an indicator which may be adjusted by band for the purpose
above specified.
Instead of making the lens of the ordinary spherical form, we prefer to make it in
the form of a paraboloid, for example as shewn in the drawing, and to use a parabolic
reflector. Whatever may be the shape of the reflector used, it is advantageous to
employ a lens of corresponding shape and to so adjust the reflector relatively to the
lens that their foci will correspond or coincide as described in the aforesaid provisional
specification.
The lamp or apparatus shown in Figures 1 and 2 will serve very efficiently as a
"head lamp" or {
tail lamp" for use on a railway carriage or locomotive.
The lamp shewn in Figures 3 and 4 is designed as a "side lamp" for a railway
carriage. It has two lenses band a double reflector, that is to say, two parabolic
reflectors c portions of which are cut off through a plane perpendicular to their axes
and which are united at c*, the electric incandescence lamp f being placed in the
centre as shown.
When used for railway purposes, our improved lamp affords, amongst others, the
following advantages, viz. There are no external wires or connections, therefore the
lamp can be readily transferred from one vehicle to another, and no disconnection
of wires is necessary when slipping a carriage. There is no need of ventilation,
therefore the casing can be made without a chimney or ventilator and can be tightly

page_text: closed so as to exclude dust. No trimming is required as in oil-lamps, and there is no
smoke, grease or soot to dim the lens and obscure the light. The light cannot be
affected or extinguished as in oil-lamps by air currents or eddies produced by the
motion of the train or otherwise. There is no risk of fire in case of breakage of the
lamp in a collision or other accident. The lamp can be easily handled and the battery
can be very readily withdrawn, recharged and replaced.
We sometimes provide interchangeable slides of green or other colored glass (as
shewn, for example, at i in Figure 1) which can be very readily inserted in, and with-
drawn from the lantern or lamp-casing for the purpose of changing or determining
the color of the light. For railway purposes, our lamp has the further advantage that
these slides can be changed without liability to extinction of the light when the door
of the casing is opened; the necessity for any mechanical devices for changing them
without opening the said casing is thus obviated.
We do not confine ourselves to any special form or construction of the parts of our
improved lamp, as these will depend to a great extent upon the purpose for which the
lamp is required, and can be considerably modified without departing from the nature
of our invention.
It is evident that our improved apparatus may be adapted for telegraphing by means
of "flashing" signals, by providing it with a movable shutter or disc for obscuring
the light when necessary.
Having now particularly described and ascertained the nature of our said invention
and in what manner the same is to be performed, we wish it understood that, in our
present application for Letters Patent, we make no claim per se for the employment
of a parabolic lens, nor do we make any claim irrespectively of our other improve-
ments herein set forth, for the use, in combination with a parabolic lens, of a parabolic
reflector as, and for the purpose, above specified, but we claim :-
First. The combination, with a lantern or lamp-casing, of an electric lamp, a lens
and reflector of parabolic or other form, and an electric battery or accumulator, for
the purposes above specified.
Second. The improved means, substantially as set forth, whereby we provide for
simultaneously closing the battery and securing it within the lantern or casing as
above specified.
Third. The improved lamp or lighting apparatus consisting of the parts constructed
and combined substantially as described with reference to Figures 1 and 2 or to
Figures 3 and 4 of the drawings for the purposes specified.
Dated 1715, da.
1007
Unted the 17th 1
1007
AUCT
JAMES THORNE,
E. B. BURR.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.