IMPROVEMENTS IN AND RELATING TO ELECTRIC LAMPS, AND TO A METHOD OF CHARGING SUCH LAMPS WITH AN ARTIFICIAL ATMO- SPHERE AND PURIFYING THE SAME, AND TO THE PRODUCTION OF A CARBON FOR USE IN ELECTRIC LAMPS, AND FOR OTHER ELECTRIC PURPOSES."
Year: 1878

page_text: LETTERS PATENT to Frederick John Cheesbrough, of the Office for Patents,
15, Water Street, Liverpool, in the County of Lancaster, Consulting Engineer,
for the Invention of "IMPROVEMENTS IN AND RELATING TO ELECTRIC LAMPS,
AND TO A METHOD OF CHARGING SUCH LAMPS WITH AN ARTIFICIAL ATMO-
SPHERE AND PURIFYING THE SAME, AND TO THE PRODUCTION OF A CARBON
FOR USE IN ELECTRIC LAMPS, AND FOR OTHER ELECTRIC PURPOSES." A com-
munication from abroad by William Edward Sawyer, of New York City, County,
and State, and Albon Man, of Brooklyn, County of Kings, State of New York,
United States of America.
PROVISIONAL SPECIFICATION left by the said Frederick John Cheesbrough
at the Office of the Cominissioners of Patents on the 28th November 1878..
FREDERICK JOHN CHEESBROUGH, of the Office for Patents, 15, Water Street,
Liverpool, in the County of Lancaster, Consulting Engineer. "IMPROVEMENTS
IN AND RELATING TO ELECTRIC LAMPS, AND TO A METHOD OF CHARGING SUCH
LAMPS WITH AN ARTIFICIAL ATMOSPHERE AND PURIFYING THE SAME, AND TO THE
PRODUCTION OF A CARBON FOR USE IN ELECTRIC LAMPS, AND FOR OTHER ELECTRIC
PURPOSES." [A communication from abroad by William Edward Sawyer, of New
York City, County, and State, and Albon Man, of Brooklyn, County of Kings, State
of New York, United States of America.]
The object of this Invention is,-
Firstly. The production of an improved electric lamp.
Secondly: A better method of charging the lamp with an artificial atmosphere
and of purifying the same.
Thirdly. The production of a better carbon for the use of electric lamne and oth

page_text: clusion point out specifically of what the Invention and improvements consist,
reference being had to the Drawing accompanying and making part of this Specifi-
cation.
At the present day it is not new to produce a light by causing the electric current
to heat a carbon conductor to incandescence in a vacuum, or in nitrogen, or in other
gas, but no lamp has yet been devised which would be practically operative, and for
these reasons,―
First. The methods that have been employed for charging the lamp with artificial
atmosphere, such as the displacement of mercury, water, or air by the gas, or the
combustion of phosphorus in the lamp, are imperfect. A perfect vacuum is un-
atainable; some oxygen or other element or compound remains in the lamp, and
slow consumption or disintegration takes place, for the remanent gas or vapour
other than nitrogen, oxygen forming with it carbonic acid or oxide, which in turn
is decomposed, with the result of depositing the carbon upon the globe, and setting
free the oxygen to attack fresh carbon.
Second. It has been found practically impossible under the varying degrees of
heat and pressure to maintain perfect joints, and the result is that expansion of the
artificial atmosphere by the heat from the luminous conductor expels a portion of
the same, and the contraction of the atmosphere upon cooling causes a portion of
the external air to penetrate the globe, thus supplying oxygen, which at the next
lighting feeds upon the carbon.
Third. The unequal expansion of the carbon and its holders has resulted in
fractures of the former, so that however perfect the atmosphere in the globe the
lamp has never been permanent.
To obviate these several difficulties is the object of this Invention.
To charge the lamp it is preferred to employ nitrogen gas, and this is produced in
the lamp by an improved process in a state of great purity.
As a safeguard against an infinitessimal leakage it is preferred to place in the
lamps a small quantity of sodium, potassium, or other agent having a great affinity
for oxygen, whose oxidization, unlike the oxidization of phosphorous, produces no
vapour, but a solid not easily changed by licat. As an additional safeguard it is
preferred to place in the lamps a quantity of freshly burned lime, so that any traces
of carbonic acid gas which might suffer the decomposition and depositing herein
before mentioned may be quickly absorbed and rendered harmless.
To make the lamp perfectly air tight recourse is had to certain fittings to the
opening at the base of the globe, which will be described in detail hereinafter.
To guard against great heating and unequal expansion at the joints, which would
imperil the scaling of the lamp and soon render it useless, the incandesent carbon is
isolated from the lower part of the globe where the joints are situated by a disk or
diaphragm of some refractory substance, preferably soapstone or porcelain, whereby
all downward radiation of the heat is prevented and the joints kept comparatively
cool, at the same time the upper part of the globe may be very hot.
Furthermore to prevent conduction of the heat from the incandesent carbon to
the joints by the metallic connection communicating therewith, two conductors
leading upward from the base are arranged in a spiral, volute, or fluting form, so as
to obtain considerable length of conductor in a limited space, and very little of the
heat reaches the base. By means of the several devices shown and described a
permanently air tight lamp is obtained. The arrangement for avoiding fracture of
the carbon will be fully described hereinafter.
In the Drawings Figure 1 is a side view, and Figure 3 a partial front view of the
lamp; Figures 2, 6, and 7 are views of parts thereof; in Figures 4, 5, and 8 are
indicated possible modifications of the lamp; and in Figure 9 is shown the general
arrangement of apparatus for charging the lamp with artificial atmosphere in
which the carbon is preserved.
Referring to Figures 1 and 3, A is the glass globe provided with a rim or flange A¹ 5
(better shown in Figure 6) by means of which it is clamped to the glass base or
stannon R /hotton chown in

page_text: The globe is shown in the form of a tube closed at one end, but it is clear that
its shape may greatly differ from that shown. The glass may be "diamond cut"
to effect diffusion of the light, or translucent to soften it; or the globe may be sur-
rounded by a second globe possessing these characteristics, and a second globe would
in fact be necessary in a lamp placed out of doors or subject to wetting as the
heated globe A if unprotected would be in great danger of breakage.
To the base of the globe is ground the glass stopper B (better shown in Figure 7)
with great nicety in order that the fit may be perfect.
Slipping over the top of the globe A is a brass flange L (shown partially cut
away), which bears upon the rim A' to bring the globe firmly down upon the
stopper B, the pressure upon the rim of the globe being softened and equalized by
the cushioned flange of wood, paper, or other yielding substance P.
Under the stopper B is placed, first, a flange of wood or other yielding sub-
stance M; second, a flange of spring rubber N; and last, a flange of brass O, all
shown partially cut away. Through all these flanges and flange L go the bolts J, J,
of which there may be any number, so distributed around the circle as to equalize
the pressure upon the rin A' and stopper B. The bolts J, J, are secured in the
usual manner by nuts K, K. The flange P softens the pressure upon the rim of the
globe A', preventing fracture; the brass flange L yields to any inequalities which
may exist. The wooden flange M softens the pressure upon the stopper B, pre-
venting fracture thereof, while it is unaffected by any heat that may there exist;
and the rubber flange N, protected from the heat, acts as a spring to yield to slight
unequal expansions and maintain a perfect contact between A¹ and B. The rubber
flange may however be omitted, and the form of the stopper B may be changed to
that of a stopper ground into the end of the globe A, as stoppers are ground
into bottles.
In setting up the lamp, the lower ground edge of the rim A² is slightly coated
with fur balsam or some cement, in order the better to insure that hermetical
sealing which is indispensible to the preservation of the incandesent conductor.
Through the stopper B are drilled two holes, Figure 7, through which pass the
bolts QQ, protected or not by a cloth or paper lining. These bolts are tubes, and
their function is of the greatest importance. The bolt heads are accurately fitted
to the upper surface of the stopper, and under them, coated with balsam or some
cement, are thin paper or tinfoil washers 7, . The nuts m m, are accurately fitted
to the under surface of the stopper, and under them are similar washers 1, 1,
similarly prepared. Thus arranged, the bolts are permanently fixed to the base,
and when the lamp is charged with the artificial atmosphere required the binding
posts n, n, whose set screws are o, o, similarly guarded by washers 1, 1, are set up
upon the bolts' ends, whereby the lamp is hermetically sealed. Entering the bolt
heads Q, Q, so as to form a perfect connection with them, are two tubes J, K,
arranged fluting, volutely, or spirally, as desired, the tube K being closed at the
top but provided with an opening i, and the tube J being continuous so that com-
munication with the top of the lamp, when the binding posts n, n, are removed, is
by way of the tube J, and to the base of the lamp by tube K at point i. The
object of this arrangement will herein after be made apparent. C is a disk of
soap-stone, porcelain, or other refractory substance, if isolated, a metal not readily
fractured by heat, which almost entirely fills the globe A at or near the middle
thereof. This, like the glass stopper B, is perforated with two holes, through which
pass the metal tube H and the metal rod I, both of which are provided with a
screw thread at their lower ends. The tube H and the rod I are firmly fixed to
the disk by means of nuts f, f, f, f, as will be comprehended without further
explanation.
Into the lower ends of H and I, and firmly fixed thereto in any manner whatso-
ever, enter the conducting tubes J and K. Let into the rod I is a short stick of
carbon D rounded at the top, which it is preferred to fasten to the rod by winding
around the two the naked wire h, which may be copper, silver, or platina.
Sliding up and down in the tube H is a rod F bent at right angles at the top, so

page_text: as to bring the extremity on a line above the carbon D. The rod F is prevented
from turning in the tube H by the pin d fixed to the rod, and working in the
slot e.
The light is produced by the heating of the small carbon rod E at the point E¹
between the clamp G and the top of the carbon D, connection with the small
carbon E being had both through clamp G and the platina piece a on bent
rod F.
The rod F exerts a pressure upon the carbon E, which continues the same with-
out regard to the length of the carbon, and thus, should fracture or slight consump-
tion of the carbon occur at the first lighting, or any subsequent lighting of the
lamps, the necessity of taking down the same, renewing the carbon, and recharging
the globe is obviated, inasmuch as the weight of the rod F gently forces the carbon
through the clamp until a new contact between E and D is established.
The construction of the clamp G is shown in Figure 2, which is a top view of the
same. It consists of a copper or silver strip bent around the tube H and fixed to
the same either by a pin or by its own pressure. At the end of the clamp are
pinned two pieces of platina or irridium b, b, which may or may not touch each
other, but each of which is slightly grooved to form an opening C through which
the carbon rod E may pass, and in which it may be held in place. The cross piece
of copper g pinned to the copper or silver strip which constitutes the main portion
of the clamp serves the purpose, through its expansibility, of increasing and lessen-
ing the distance between the platina pieces b, b, according to the degree of heat
experienced thereby, in a great measure avoiding fracture of the carbon at E¹ when
intensely heated by the current.
In setting up the lamp it is preferred to place inside the globe a lump of sodium
or potassium R and one or more lumps of freshly burned lime S, although this
Invention is not confined to the introduction of these substances; sodium and
potassium being conductors of electricity may be protected from the conductors to
the carbon, if deemed necessary, by enclosing the same in a bag of cloth or in
a glass tube open at one end.
It is known that phosphorous has been placed in sealed lamps to remove the
oxygen by its slow combustion, but the phosphorous acid evolved is not only fatal
to the carbon when intensely heated but beclouds the globe and obscures the light.
Neither sodium nor potassium exert any such deleterious influence; the product of
oxidization being a solid, incapable under the circumstances of yielding either gas
or vapour of any kind, hence the use of such as a safeguard in the lamp. Should
carbonic acid gas exist, or at any time be evolved in the lamp, it is quickly taken
up by the lime, or by the soda or potassa formed by oxidization of the sodium or
potassium.
In Figures 4 and 5 is indicated a modification of the lamp to the chandelier
form. Any number of carbons D and E may be arranged around a circle in the
form shown in Figures 1 and 2, having for each a feeding device F, G, the whole
being in a single globe; or the chandelier, as shown, may be arranged as shown in
Figure 4, U being a metal disk provided with five or more or less tubes U¹, in
which slide the small carbon rods E, E, which are forced into contact with the
lower carbons D, D, by the downward pressure of rods T surmounted by the
weights T, T. All of the lower carbons D connect with the disk V to which is
fixed tube V', and through this tube and the disk, but insulated therefrom, passes
the conductor W which is attached to the upper disk U, and is therefore in
connection with all the small carbons E.
In Figure 8 is indicated a modification of the single carbon lamp, the clamp G
being dispensed with and the bent rod F being provided, like the rod 1 of Figure 1,
with a carbon piece X wired to it precisely as carbon D is wired to rod I.
The lamp being set up the next important thing is to charge it with the atmo-
sphere which will prevent consumption of the carbon, and the detail description of
the improved process of charging the lamp is as follows:-
.
-
The various methods of manufacturing nitrogen gas are well known. Having

page_text: dried and purified the gas until it stands all tests it is passed into a dry receiver,
preferably a bag of vulcanized rubber. Referring now to Figure 9, into a glass
tube p, p, in a furnace Z, by means of which the tube may be heated to any
desired extent, is placed a quantity of sodium or potassium, or other agent having
a great affinity for oxygen whose oxidization produces a solid. If deemed advisable
there inay be added the same purifying agent or agents. Heat, while not essential,
greatly facilitates the operation, and therefore, even with potassium, it is preferred
to employ the furnace. To one end of the glass tube p, p, by means of a flexible
tube T,
attached the receiver Y filled with nitrogen, and having removed the
binding posts n, n, Figure 1, from the lamp, the other end of the tube is connected
by means of a flexible tuber and nipple S with the bolt Q which connects with
the tube J leading up to the top of the lamp.
By means of weight q a sufficient quantity of the nitrogen is forced through
the tube p.and the lamp-to greatly dilute and mostly displace the atmospheric air
contained therein. The empty closed receiver Y is then attached by flexible tube
and nipples S to the bolt Q which is connected to conductor K of the lamp, and
the lamp being now in a closed circuit of nitrogen gas the operation of purification
begins. The gas passes slowly from the receiver Y through tube p, thence through
the tube J to the top of the lamp at the point U, and thence down and outward at
the point t into the receiver Y, and from Y by the reverse action it is repassed into
receiver Y. This transference is repeated until there is no further evidence of
oxidization, when the receiver Y' being empty a pressure is exerted upon the
receiver Y and maintained so as to cause a slight escape of gas from the lamp
during the time that Y¹ is disconnected, and the binding post being put into the
bolt connecting with conductor K. The nipple S is lastly disconnected from the
bolt of tube J, and the binding post for that tube put on, when the lamp is
ready for use, and will remain so for an indefinite period, the lime S in the lamp
absorbing any traces of of carbonic acid gas that may be present or evolved, and the
sodium or potassium burning out any traces of oxygen that may enter during the
closing of tube J.
By the process described the lamp may be charged with absolutely pure nitrogen
gas; and it is clear that any number of lamps may be placed in the circuit and
simultaneously charged, the gas in transference passing seriatim through the lamps.
There has been shown and described an electric lamp in which a pencil of carbon
is heated to incandesence in a nitrogen or other carbon preservative atmosphere.
One of the principal obstacles to successful electric lighting by incandesence is the
dissociated character of nearly all obtainable carbon. In most of such carbon there
is danger of fracture, as well as of the establishment of the voltaic arc; and
furthermore, the carbon, unless specially prepared by this process, naturally occludes
sufficient air or oxygen to render its consumption a mere question of time, since, as
fully set forth, the least quantity of oxygen in a sealed lamp is sufficient to combust
an indefinite quantity of carbon.
As is well known carbon suitable for electric lighting by the voltaic arc is
naturally produced in gas retorts, but generally the rods of carbon used in the
"regulator" lamps, so called, are moulded from the powdered material. Neither
the one nor the other quality of carbon is suitable for electric lighting by incan-
desence. In both there is a lack of homogeneity. The pencil is not sufficiently
hard and dense, because in the first place the heat required to produce the proper
character of carbon is as high as 7,000° Fahrenheit, and such a temperature is not
obtainable in the retort; and in the second place, the mechanical subdivisions of the
material and the pressure necessary to produce the perfect article are practically
unattainable. Carbon of the ordinary sort when heated by the electric current
exhibits points and lines of unequal brilliancy. Carbons prepared by this process
when so heated glow with a uniform brilliancy throughout.
It has been found that a pencil of carbon immersed in a hydrocarbon gas or
liquid, and heated to an extremely high temperature by the voltaic current, is not

page_text: itself attacked, but decomposes the surrounding matter, the carbon of which enters
and fills up its pores to an extent impossible except with matter in a very attenu-
ated state, and deposits a perfectly homogeneous layer, generally of a bright gray
colour, upon the exterior surface. As the carbon increases in size more current is
required to maintain its temperature, and if the current is gradually increased in
accordance with the demand for it there is appearingly no limit to the increase in
mass of the homogeneous exterior deposit. Carbon pencils may be cut from this
deposit; or the original pencil with its coating may be used in the lamps.
In this process it would seem that the carbon is never in contact with the liquid
in which it is immersed, but surrounded by a carbonic gas of a very high temper-
ature; naptha, turpentine, bees-wax, balsam, and most oils, if pure, operate satis-
factorily almost any hydro carbon, in fact, will answer.
This Invention is not confined to the treatment of carbon alone, since it is obvious
that many infusible substances, non conductors of electricity, may be heated in
hydrocarbon liquids or gases, so as to render them conductors of electricity, as, for
instance, a tube of lime enclosing a pencil of carbon, through which the electric
current is caused to circulate.
The beforegoing is a descriptive method of charging a sealed globe with pure
nitrogen gas; let it be supposed that the pencil of carbon held between two carbon
pieces of greater mass than that of the pencil, as above described, is immersed in
the hydro carbon liquid, and heated in the manner already described, being then
cleansed in alcohol, the pencil and its holders without having been disturbed and
placed in the globe in which they are to be hermetically sealed.
The globe is charged with pure nitrogen, and then, while still allowing pure
nitrogen to flow into and out of the globe, the carbon is heated to incandesence,
thus driving out all impurities and occluded gases, which are carried out of the lamp
by the current of nitrogen. With this operation the preparation of the carbon is
completed, and the lamp now being hermetically sealed, as above described, is ready
for use.
In concluding this description the fact must be pointed out that the consolidated
homogeneous carbon of this Invention may be produced by the electro platina
process, as well as by the electrical heating of a conductor in a carbon gas or liquid.
The cathode, composed either of solid carbon or of an infusible refractory substance,
coated with plumbago or graphite, is immersed in a carbon liquid, and connected
with one pole of the battery. The other pole of the battery is connected with the
anode, composed of solid carbon, also immersed in the liquid. The passage of the
current decomposes the liquid and deposits a homogeneous layer of carbon upon the
cathoide.
This Invention also covers substantially the following points or parts in combi-
nation and in detail, and are intended to be embraced and included in the Invention,
of which this is a Specification.
First. An electric lamp, in which the globe and stopper, both of glass or other
vitreous substance, are ground together, and held together by a clamping device.
Second. In an electric lamp the combination with suitable conductors of electricity
of an inclosing globe provided with a rim or flange A', forming an integral part of
such globe, as and for the purpose specified.
Third. The combination of the vitreous globe A of an electric lamp, and the
cushion P placed as shown and described above the vitreous flange thereof, for the
purpose of supporting a clamping device.
Fourth. The combination of the vitreous globe A of an electric lamp and the
cushion N placed, as shown and described, under the stopper thereof, for the purpose
of supporting a clamping device.
Fifth. The combination of the globe of an electric lamp and the two cushions N
and P, placed as shown and described, for the purpose of supporting a clamping
davina

page_text: Sixth. In an electric lamp a tube bolt Q and binding post n, in combination with
a packing under said binding post.
Seventh. In an electric lamp a tube bolt Q, nut m, binding post n, and packings
Ն, Ն, Ն.
Eighth. The combination of the clamp G and the cross piece g, as and for the
purpose specified.
Ninth. In an electric lamp a tube leading from an external connection to or near
to the top of the globe, and having an opening at or near to the base of the globe,
for the purpose of facilitating the filling of the globe with a carbon preservative
atmosphere, substantially as shown and described.
Tenth. In an electric lamp two unobstructed tubes, leading from external connec-
tions into the globe thereof, and so arranged as to facilitate the charging of the globe
with a carbon preservative atmosphere.
Eleventh. In an electric lamp a diaphragm obstructive-of-radiant heat interposed
between the luminous part or parts of such lamp and the air tight joint or joints
thereof, as and for the purpose specified.
Twelfth. An electric lamp, within which the conductors leading from the air tight
joint or joints thereof to the luminous part or parts thereof are so formed, length-
ened, or broadened as to have great radiating surface, so that the conduction of heat
from such part or parts to such joint or joints is in great measure if not wholly
prevented.
Thirteenth. In an electric lamp the long coiled conductor J, opening at its upper
end and connecting with one electrode of such lamp.
Fourteenth. In an electric lamp the long coiled conductor K, opening. at the base
of such lamp, and connecting with one electrode thereof.
Fifteenth. In an electric lamp an absorbent of carbonic acid gas.
Sixteenth. In the sealed globe of an electric lamp, containing an ozotic or other
carbon preservative atmosphere an absorbent of carbonic acid gas.
Seventeenth. In an electric lamp an agent having a great affinity for oxygen,
whose oxidization produces a solid unalterable by the natural heat in the lamp, such
as sodium or potassium.
Eighteenth. The combination in an electric lamp of an absorbent of carbonic acid
gas, and an agent having a great affinity for oxygen, whose oxidization produces a
solid unalterable by the natural heat in the lamp, such as sodium or potassium.
Nineteenth. A carbon, rod piece, or pencil heated to incandesence in an atmo-
sphere deprived of oxygen, in which atmosphere is permanently an oxidizing agent
whose oxidization produces a solid, which agent may be sodium, or potassium, or
other readily oxidizable metal.
Twentieth. A carbon rod piece or pencil heated to incandesence in an atmosphere
deprived of oxygen, in which atmosphere is permanently an absorbent of carbonic
acid gas.
Twenty first. A carbon rod piece or pencil, heated to incandesence in an atmo-
sphere deprived of oxygen, in which atmosphere is permanently an oxidizing agent,
such as sodium, potassium, or other readily oxidizable metal, in combination with an
absorbent of carbonic acid gas.
Twenty second. A sealed electric lamp, enclosing an agent or agents for purifying
the atmosphere contained herein from oxygen or oxygenic gases.
Twenty third. The hereinbefore described method of charging an electric lamp
with a carbon preservative atmosphere, consisting in placing the lamp in the circuit.
of a purifying agent or agents and two gas receivers, one of which is primarily
preferably filled with the carbon preservative gas, and the other empty and forcing
the gas back and forth from one receiver to the other, each time through the
lamp and the purifying agent or agents until the atmosphere becomes pure, or
nearly so.
Twenty fourth. The hereinbefore described method of charging an electric lamp
with a carbon preservative atmosphere, consisting in placing the lamp in a circuit

page_text: of a purifying agent or agents and two receivers, one of which is primarily prefer-
ably filled with a gaseous medium, and the other empty, and forcing the gaseous
medium back and forth from one receiver to the other, each time through the lamp
and the purifying agent or agents until the atmosphere in the lamp becomes pure,
or nearly so.
Twenty fifth. The method of charging an electric lamp with a carbon preserva-
tive gas, by intermittently passing a purified atmosphere, or an atmosphere under-
going purification, into the globe thereof, and thereby successively diluting and
purifying the contents thereof until finally all, or nearly all, the oxygen is removed
therefrom.
Twenty sixth. The herein described method of preparing the illuminating part
of an electric lemp, consisting of électrically heating the same while it is surrounded
by a carbon gas or liquid.
Twenty seventh. A material for the manufacture of the illuminating conductors
of electric lamps, produced by electrically heating carbon in a carbon gas.
Twenty eighth. The illuminating part of an electric lamp, consisting of carbon
deposited by electric action.
Twenty ninth. A material for the manufacture of the illuminating conductors of
electric lamps produced by electric action.
Thirtieth. The hereinbefore described method of preparing the illuminating part
of an electric lamp, consisting in first obtaining a solid deposit of carbon by electric
action, as set forth, and subsequently, when the globe containing it is charged with
a carbon preservative atmosphere, before the flow of such preservative atmosphere
through the lamp has ceased, and before the lamp is finally sealed, heating the
illuminating part by means of the electric current in order to expel impurities and
occulder gases.

page_text: The object of this Invention is,-
Firstly. The production of an improved electric lamp.
Secondly. A better method of charging the lamp with an artificial atmosphere,
and of purifying the same.
Thirdly. The production of a better carbon for the use of electric lamps and other
electric purposes.
The following detail description of this Invention and improvements will fully
explain and illustrate their practical application and advantage, and in conclusion
point out specifically of what the Invention and improvements consist,. reference
being had to the Drawing accompanying and making part of this Specification.
At the present day it is not new to produce a light by causing the electric current
to heat a carbon conductor to incandescence in a vacuum, or in nitrogen, or in other
gas, but no lamp has yet been devised which would be practically operative, and
for these reasons:-
First. The methods that have been employed for charging the lamp with artificial
atmosphere, such as the displacement of mercury, water, or air by the gas or the
combustion of phosphorous in the lamp are imperfect. A perfect vacuum is unattain-
able; some oxygen or other element or compound remains in the lamp, and slow
consumption or disintegration takes place, for the remanent gas, or vapour, or other
than nitrogen, oxygen forming with it carbonic acid or oxide which in turn is
decomposed, with the result of depositing the carbon upon the globe and setting
free the oxygen to attack fresh carbon.
Second. It has been found practically impossible under the varying degrees of
heat and pressure to maintain perfect joints, and the result is that expansion of the.
artificial atmosphere by the heat from the luminous conductor expels a portion of
the same, and the contraction of the atmosphere upon cooling causes a portion of
the external air to penetrate the globe, thus supplying oxygen, which at the next
lighting feeds upon the carbon.
Third. The unequal expansion of the carbon and its holders has resulted in
fractures of the former, so that however perfect the atmosphere in the globe the lamp
has never been permanent.
To obviate these several difficulties is the object of this Invention.
To charge the lamp it is preferred to employ nitrogen gas, and this is produced in
the lamp by an improved process in a state of great purity.
As a safe guard against an infinitessimal leakage it is preferred to place in the
lamps a small quantity of sodium, polassium, or other agent having a great affinity
for oxygen, whose oxidization, unlike the oxidization of phosphorous, produces no
vapour, but a solid not easily changed by heat. As an additional safeguard it is
preferred to place in the lamps a quantity of freshly burned lime, so that any traces
of carbonic acid gas which might suffer the decomposition and depositing herein
before mentioned may be quickly absorbed and rendered harmless.
To make the lamp perfectly air tight recourse is bad to certain fittings to the
opening at the base of the globe, which will be described in detail hereinafter.

page_text: To guard against great heating and unequal expansion at the joints, which would
imperil the sealing of the lamp and soon render it useless, the incandescent carbon
is isolated from the lower part of the globe, where the joints are situated, by a disk
or diaphragm of some refractory substance, preferably soap-stone or porcelain,
whereby all downward radiation of the heat is prevented and the joints kept com-
paratively cool, at the same time the upper part of the globe may be very hot.
Furthermore, to prevent conduction of the heat from the incandescent carbon to
the joints by the metallic connection communicating therewith two conductors
leading upward from the base are arranged in a spiral volute or fluting form so as
to obtain considerable length of conductor in a limited space, and very little of the
heat reaches the base. By means of the several devices shown and described &
permanently air tight lamp is obtained. The arrangements for avoiding fracture of
the carbon will be fully described hereinafter.
In the Drawings Figure 1 is a side view, and Figure 3 a partial front view of the
lamp. Figures 2, 6, and 7 are views of parts thereof. In Figures 4, 5, and 8 are
indicated possible modifications of the lamp, and in Figure 9 is shown the general
arrangement of apparatus for charging the lamp with artificial atmosphere, in which
the carbon is preserved.
Referring to Figures 1 and 3, A is the glass globe provided with a rim or flange A¹
(better shown in Figure 6), by means of which it is clamped to the glass base or
stopper B (better shown in Figure 7).
The globe is shown in the form of a tube closed at one end, but it is clear that its
shape may greatly differ from that shown. The glass may be "diamond cut" to
effect diffusion of the light, or translucent to soften it, or the globe may be sur-
rounded by a second globe possessing these characteristics; and a second globe
would in fact be necessary in a lamp placed out of doors or subject to wetting, as
the heated globe A if unprotected would be in great danger of breakage.
To the base of the globe is ground the glass stopper B (better shown in Figure 7)
with great nicety in order that the fit may be perfect.
Slipping over the top of the globe A is a brass flange L (shown partially cut
away) which bears upon the rim A' to bring the globe firmly down upon the
stopper B, the pressure upon the rim of the globe being softened and equalized by
the cushioned flange of wood, paper, or other yielding substance P.
Under the stopper B is placed first a flange of wood or other yielding substance M;
second, a flange of spring rubber N; and, last, a flange of brass O, all shown par-
tially cut away. Through all these flangss and flange L go the bolts J, J, of which
there may be any number, so distributed around the circle as to equalize the pressure
upon the rim A' and stopper B. The bolts J, J, are secured in the usual inanner
by the nuts K, K. The flange P softens the pressure of the globe A¹, pre-
venting fracture; the brass flange L yields to any inequalities which may exist.
The wooden flange M softens the pressure upon the stopper B, preventing fracture
thereof, while it is unaffected by any heat that inay there exist, and the rubber
flange N protected from the heat acts as a spring to yield to slight unequal expan-
sions and maintain a perfect contact between A' and B. The rubber flange may
however be omitted, and the form of the stopper B may be changed to that of a
stopper ground into the end of the globe A as stoppers are ground into bottles.
In setting up the lamp the lower ground edge of the rim A' is slightly coated
with fur balsum or some cement in order the better to insure that hermetical sealing
which is indispensible to the preservation of the incandescent conductor.
Through the stopper B are drilled two holes, Figure 7, through which pass the
bolts QQ protected or not by a cloth or paper lining. These bolts are tubes, and
their function is of the greatest importance. The bolt heads are accurately fitted
to the upper surface of the stopper, and under them, coated with balsam or some
cement, are thin paper or tinfoil washers 1, 1. The nuts m, m, are accurately fitted
to the under surface of the stopper, and under them are similar washers 1, 1, similarly
prepared. Thus arranged the bolts are permanently fixed to the base, and when
the lamp is charged with the artificial atmosphere required the binding posts n, n,

page_text: whose set screws are O, O, similarly guarded by washers 1, 1, are set up upon the
bolts ends, whereby the lamp is hermetically sealed. Entering the bolt heads Q, Q,
so as to form a perfect connection with them, are two tubes J, K, arranged fluting,
volutely, or spirally, as desired, the tube K being closed at the top, but provided
with an opening i, and the tube J being continuous, so that communication with
the top of the lamp when the binding posts m, n, are removed is by way of the
tube J, and to the base of the lamp by tube K at the point i. The object of this
arrangement will hereinafter be made apparent. C is a disk of soap stone, porcelain,
or other refractory substance, if isolated, a metal not readily fractured by heat,
which almost entirely fills the globe A at or near the middle thereof. This like the
glass stopper B is perforated with two holes through which pass the metal tube H
and the metal rod I, both of which are provided with a screw thread at their lower
ends. The tube H and the rod I are firmly fixed to the disk by means of nuts f,f,f,f,
as will be comprehended without further explanation.
'
Into the lower ends of H and I and-firmly fixed-thereto in any manner what-
soever enter the conducting tubes J and K. Let into the rod I is a short stick of
carbon D rounded at the top, which it is preferred to fasten to the rod by winding
around the two the naked wire h which may be copper, silver, or platina.
Sliding up and down in the tube H is a rod F bent at right angles at the top so
as to bring the extremity on a line above the carbon D. The rod F is prevented
from turning in the tube H by the pin & fixed to the rod and working in the
slot e.
The light is produced by the heating of the small carbon rod E at the point E¹,
between the clamp G and the top of the carbon D, connection with the small
carbon E being had both through clamp G and the platina piece a on bent rod F.
The rod F exerts a pressure upon the carbon E which continues the same without
regard to the length of the carbon, and thus should fracture or slight consumption
of the carbon occur at the first lighting or any subsequent lighting of the lamps,
the necessity of taking down the same, renewing the carbon, and recharging the
globe is obviated, inasmuch as the weight of the rod F gently forces the carbon
through the clamp until a new contact between E and D is established.
The construction of the clamp G is shown in Figure 2 which is a top view of the
same. It consists of a copper or silver strip bent around the tube H and fixed to
the same either by a pin or by its own pressure. At the end of the clamp are
pinned two pieces of platina or iridium b, b, which may or may not touch each
other, but each of which is slightly grooved to form an opening c through which
the carbon rod E may pass, and in which it may be held in place. The cross piece
of copper g pinned to the copper or silver strip, which constitutes the main portion
of the clamp, serves the purpose through its expansibility of increasing and lessening
the distance between the platina pieces b, b, according to the degree of heat
experienced, thereby in a great measure avoiding fracture of the carbon at E' when
intensely heated by the current.
In setting up the lamp it is preferred to place inside the globe a lump of sodium
or potassium R, and one or more lumps of freshly burned lime S, although this
Invention is not confined to the introduction of these substances, sodium and
potassium being conductors of electricity may be protected from the conductors to
the carbon if deemed necessary by enclosing the same in a bag of cloth or in a
glass tube open at one end.
It is known that phosphorous has been placed in sealed lamps to remove oxygen
by its slow combustion, but the phosphorous acid evolved is not only fatal to the
carbon when intensely heated, but beclouds the globe and obscures the light.
Neither sodium or potassium exert any such deleterious influence, the product of
oxidization being a solid, incapable under the circumstances of yielding either gas
or vapour of any kind, hence the use of such as a safeguard in the lamp. Should
carbonic acid gas exist or at any time be evolved in the lamp, it is quickly taken
up by the lime or by the soda, or potassa formed by oxidization of the sodium or
potassium,

page_text: In Figures 4 and 5 is indicated a modification of the lamp to the chandelier
form, any number of carbons D and E may be arranged around a circle in the form
shown in Figures 1 and 2, having for each a feeding device F, G, the whole being
in a single globe, or the chandelier as shown may be arranged as shown in Figure 4,
U being a metal disc provided with five, or more or less, tubes U¹, in which slide
the small carbon rods E, E, which are forced into contact with the lower carbons
D, D, by the downward pressure of rods T¹ surmounted by the weights T, T. All of
the lower carbons D connect with the disk V to which is fixed tube V', and through
this tube and the disk, but insulated therefrom, passes the conductor W which is
attached to the upper disk U, and is therefore in connection with all the small
carbons E.
In Figure 8 is indicated a modification of the single carbon lamp, the clamp G
being dispensed with, and the bent rod F being provided like the rod I of Figure 1
with a carbon piece ✗ wired to it precisely as carbon D is wired to rod I.
The lamp being set up the next important thing is to charge it with the atmo-
sphere which will prevent consumption of the carbon, and the detail description of
the improved process of charging the lamp is as follows:-
The various methods of manufacturing nitrogen gas are well known. Having
dried and purified the gas until it stands all tests it is passed into a dry receiver,
preferably a bag of vulcanized rubber. Referring now to Figure 9, into a glass
tube P, P.
in a furnace Z, by means of which the tube may be heated to any desired
extent, is placed a quantity of sodium, or potassium, or other agent, having a great
affinity for oxygen, whose oxidization produces a solid. If deemed advisable
there may be added the same purifying agent or agents. Heat, while not essential,
greatly facilitates the operation, and therefore even with potassium it is preferred
to employ the furnace. To one end of the glass tube p, p, by means of a flexible
tube is attached the receiver Y filled with nitrogen, and having removed the
binding posts n, n, Figure 1, froin the lamp, the other end of the tube p is con-
nected by means of a flexible tuber and nipple S with the bolt Q, which connects
with the tube J leading up to the top of the lamp.
By means of weight q a sufficient quantity of the nitrogen is forced through the
tube P, and the lamp to greatly dilute and mostly displace the atmospheric air
contained therein. The empty closed receiver Y is then attached by a flexible tube
and nipple S to the bolt Q which is connected to conductor K of the lamp, and
the lamp being now in a closed circuit of nitrogen gas, the operation of purification
begins. The gas passes slowly from the receiver Y through tube p, thence through
the tube J to the top of the lamp at the point U, and thence down and outward at
the point t into the receiver Y, and from Y by the reverse action it is repassed into
receiver Y. This transference is repeated until there is no further evidence of
oxidization; when the receiver Y₁ being empty a pressure is exerted upon the
receiver Y and maintained, so as to cause a slight escape of gas from the lamp
during the time that Y' is disconnected, and the binding post being put into the
bolt connecting with conductor K. The nipple S is lastly disconnected from the
bolt of tube J; and the binding post for that tube put on when the lamp is
ready for use, and will remain so for an indefinite period, the lime S in the lamp
absorbing any traces of carbonic acid gas that may be present or evolved, and the
sodium or potassium burning out any traces of oxygen that may enter during the
closing of tube J.
By the process described the lamp may be charged with absolutely pure nitrogen
gas, and it is clear that any number of lamps may be placed in the circuit and
simultaneously charged, the gas in transference passing seriatim through the
lamps.
There has been shown and described an electric lamp in which a pencil of carbon
is heated to incandescence in a nitrogen or other carbon preservative atmosphere,
one of the principle obstacles to successful electric lighting by incandescence is the
dissociated character of nearly all obtainable carbon. In most of such carbon there
is danger of fracture as well as of the establishment of the voltaic arc, and further-.

page_text: more, the carbon unless specially prepared by this process naturally occludes
sufficient air or oxygen to render its consumption a mere question of time, since as
fully set forth, the least quantity of oxygen in a sealed lamp is sufficient to combust
an indefinite quantity of carbon.
As is well known carbon suitable for electric lighting by the voltaic arc is
naturally produced in gas retorts, but generally the rods of carbon used in the
regulator lamps so called are moulded from the powdered material. Neither the
one nor the other quality of carbon is suitable for electric lighting by incandescence.
In both there is a lack of homogeneity. The pencil is not sufficiently hard and
dense, because in the first place, the heat required to produce the proper character
of carbon is as high as 7,000° Fahrenheit, and such a temperature is not obtainable
in the retort, and in the second place the mechanical subdivisions of the material,
and the pressure-necessary to produce the perfect article are practically unattainable.-
Carbon of the ordinary sort when heated by the electric current exhibits points and
lines of unequal brilliancy. Carbons prepared by this process, when so heated glow
with a uniform brilliancy throughout.
It has been found that a pencil of carbon immersed in a hydro-carbon gas or
liquid, and heated to an extremely high temperature by the voltaic current is not
itself attacked, but decomposes the surrounding matter, the carbon of which enters
and fills up its pores to an extent impossible except with matter in a very
attenuated state, and deposits a perfectly homogeneous layer, generally of a bright
gray colour upon the exterior surface; as the carbon increases in size more current
is required to maintain its temperature, and if the current is gradually increased,
in accordance with the demand for it, there is appearingly no limit to the increase
in mass of the homogeneous exterior. deposit. Carbon pencils may be cut from this
deposit, or the original pencil with its coating may be used in the lamps.
In this process it will be seen that the carbon is never in contact with the liquid
in which it is immersed, but surrounded by a carbonic gas of very high temperature ;
bees wax, balsam, and most oils if pure operate satisfactorily, almost any hydro-
carbon in fact will answer.
This Invention is not confined to the treatment of carbon alone, since it is
obvious that many infusible substances non conductors of electricity may be heated
in hydro carbon liquids or gases, so as to render them conductors of electricity, as
for instance a tube of lime enclosing a pencil of carbon through which the electric
current is caused to circulate.
The beforegoing is a descriptive method of charging a sealed globe with pure
nitrogen gas; let it be supposed that the pencil of carbon held between two carbon
pieces of greater mass than that of the pencil, as above described, is immersed in
the hydrocarbon liquid, and heated in the manner already described, being then
cleansed in alcohol, the pencil and its holders without having been disturbed and
placed in the globe in which they are to be hermetically sealed.
The globe is charged with pure nitrogen, and then while still allowing pure
nitrogen to flow into and out of the globe, the carbon is heated to incandescence,
thus driving out all impurities and occluded gases which are carried out of the
lamp by the current of nitrogen. With this operation the preparation of the
carbon is completed, and the lamp now being hermetically sealed as above described
is ready for use.
In concluding this description the fact must be pointed out that the consolidated
homogeneous carbon of this Invention may be produced by the electro platina
process, as well as by the electrical heating of a conductor in a carbon gas or liquid.
The cathode composed either of solid carbon or of an infusible refractory substance
coated with plumbago or graphite is immersed in a carbon liquid, and connected
with one pole of the battery. The other pole of the battery is connected with
the anode composed of solid carbon also immersed in the liquid. The passage
of the current decomposes the liquid, and deposits a homogeneous layer of carbon
upon the cathoide.
This Invention also covers substantially the following points or parts in com-

page_text: bination and in detail, and are intended to be embraced and meruded m
Invention of which this is a Specification,―
First. An electric lamp in which the globe and stopper, both of glass or other
vitreous substance, are ground together and held together by a clamping device.
Second. In an electric lamp, the combination with suitable conductors of
electricity of an enclosing globe provided with a rim or flange A' forming an
integral part of such globe, as and for the purpose specified.
Third. The combination of the vitreous globe À of an electric lamp, and the
cushion P, placed as shown and described above the vitreous flange thereof for the
purpose of supporting a clamping device.
Fourth. The combination of the vitreous globe A of an electric lamp, and the
cushion N, placed as shown and described under the stopper thereof for the purpose
of supporting a clamping device.
Fifth. The combination of the globe of an electric lamp, and the two cushions
N and P, placed as shown and described for the purpose of supporting a clamping
device.
Sixth. In an electric lamp, a tube bolt Q, and binding post n, in combination
with a packing under said binding post.
Seventh. In an electric lamp, a tube bolt Q, nut m, binding post n, and
packings 1, 1, 1.
Eighth. The combination of the clamp G, and the cross piece g, as and for the
purpose specified.
Ninth. In an electric lamp, a tube leading from an external connection to or
near to the top of the globe and having an opening at or near to the base of the
globe, for the purpose of facilitating the filling of the globe with a carbon
preservative atmosphere, substantially as shown and described.
Tenth. In an electric lamp, two unobstructed tubes leading from external
connections into the globe thereof, and so arranged as to facilitate the charging of
the globe with a carbon preservative atmosphere.
.
Eleventh. In an electric lamp, a diaphragm obstructive of radiant heat interposed
between the luminous part or parts of such lamp, and the air tight joint or joints
thereof, as and for the purpose specified.
Twelfth. An electric lamp within which the conductors leading from the air
tight joint or joints thereof to the luminous part or parts thereof are so formed,
lengthened, or broadened, as to have great radiating surface, so that the conduction
of heat from such part or parts to such joint or joints is in great measure if not
wholly prevented.
Thirteenth. In an electric lamp, the long coiled conductor J opening at its upper
end and connecting with one electrode in such lamp.
Fourteenth. In an electric lamp, the long coiled conductor K opening at the base
of such lamp, and connecting with one electrode thereof.
Fifteenth. In an electric lamp, an absorbent of carbonic acid gas.
Sixteenth. In the sealed globe of an electric lamp containing an ozotic or other
carbon preservative atmosphere, an absorbent of carbonic acid gas.
Seventeenth. In an electric lamp, an agent having a great affinity for oxygen
whose oxidization produces a solid unalterable by the natural heat in the lamp,
such as sodium or potassium.
Eighteenth. The combination in an electric lamp of an absorbent of carbonic acid
gas and an agent having a great affinity for oxygen, whose oxidization produces a
solid unalterable by the natural heat in the lamp, such as sodium or potassium.
Nineteenth. A carbon, rod, piece, or pencil, heated to incandescence in an
atmosphere deprived of oxygen, in which atmosphere is permanently an oxidizing
agent whose oxidization produces a solid, which agent may be sodium, or potassium,
or other readily oxidizable metal.
Twentieth. A carbon, rod, piece, or pencil, heated to incandescence in an atmo-
sphere deprived of oxygen in which atinosphere is permanently an obsorbent of
carbonic acid gas.

page_text: Twenty first. A carbon, rod, piece, or pencil, heated to incandescence in an
atmosphere deprived of oxygen, in which atmosphere is permanently an oxidizing
agent, such as sodium, potassium, or other readily oxidizable metal in combination
with an absorbent of carbonic acid gas.
Twenty second. A sealed electric lamp enclosing an agent or agents for purifying
the atmosphere contained therein from oxygen or oxygenic gases.
Twenty third. The herein before described method of charging an electric lamp
with a carbon preservative atmosphere, consisting in placing the lamp in the circuit
of a purifying agent or agents and two gas receivers, one of which is primarily
preferably filled with the carbon preservative gas, and the other empty and
forcing the gas back and forth from one receiver to the other, each time through
the lamp and the purifying agent or agents, until the atmosphere-becomes-pure-or
nearly so. -
Twenty fourth. The herein before described method of charging an electric lamp
with a carbon preservative atmosphere, consisting in placing the lamp in a circuit
of a purifying agent or agents and two receivers, one of which is primarily
preferably filled with a gaseous medium, and the other empty, and forcing the
gaseous medium back and forth from one receiver to the other each time through
the lamp and the purifying agent or agents, until the atmosphere in the lamp
becomes pure or nearly so.
Twenty fifth. The method of charging an electric lamp with a carbon pre-
servative gas by intermittently passing a purified atmosphere, or an atmosphere
undergoing purification, into the globe thereof, and thereby successively diluting
and purifying the contents thereof until finally all, or nearly all the oxygen is
removed therefrom.
Twenty sixth. The herein described method of preparing the illuminating part of
an electric lamp, consisting of electrically heating the same while it is surrounded
by a carbon gas or liquid.
Twenty seventh. A material for the manufacture of the illuminating conductors
of electric lamps, produced by electrically heating carbon in a carbon gas.
Twenty eighth. The illuminating part of an electric lamp consisting of carbon
deposited by electric action.
Twenty ninth. A material for the manufacture of the illuminating conductors of
electric lamps produced by electric action.
Thirtieth. The herein before described method of preparing the illuminating part
of an electric lamp, consisting in first obtaining a solid deposit of carbon by electric
action as set forth, and subsequently when the globe containing it is charged with
a carbon preservative atmosphere, before the flow of such preservative atmosphere
through the lamp has ceased, and before the lamp is finally sealed, heating the
illuminating part by means of the electric current, in order to expel impurities and
occulder gases.
In witness whereof, I, the said Frederick John Cheesbrough, have hereunto
set my hand and seal, this Twenty fourth day of May, in the year of our
Lord One thousand eight hundred and seventy nine
FREDERICK JOHN CHEESBROUGH. (L.s.)

page_text: I, JAMES YATE JOHNSON; of 47 Lincolns Inn Fields, in the County of Middlesex,
Gentleman, lately residing at Washington, District of Columbia, United States of
America seek leave to amend the Title and specification of Letters Patent, No. 4847
of 1878, as shown in red ink in the copy of the original specification hereunto
annexed:
1.
い
My reasons for making the amendments are as follows:-
=
That there are doubts whether the Letters, Patent are not at present invalid in
consequence of a prior publication of that portion of the Specification which is
covered by the first 25 claiming clauses which I therefore desire to disclaim.
That the portion of the Specification beginning “for the remanent gas" (line 30
page 9) and ending "fresh carbon" (line 33 of the same page) is unnecessary, and
I desire to excise the same from the said Specification.
That the 28th claim might be held to be too general and to claim more than is
described in the Specification and I am therefore desirous of limiting it so as to
make it claim only what is described in the Specification.
That there are doubts whether the 29th claim of the original Specification can be
supported and I am therefore desirous of disclaiming it.
That there are clerical errors in the said Specification which I am desirous of
correcting.
That the other alterations in the Specification are rendered necessary or con-
venient by the proposed amendments.
That the title should be amended in accordance with the proposed Amendments
in the Specification.
The said Letters Patent were assigned to me by Indenture bearing date the ninth
day of April 1884, duly registered in the Patent Office.

page_text: In the matter of Letters Patent granted to Frederick John Cheesbrough for
"Improvements in and relating to electric lamps, and to a method of charging such
lamps with an artificial atmosphere, and purifying the same, and to the production
of a carbon for use in electric lamps, and for other electric purposes," dated the
28th day of November 1878, N° 4847
AND
In the matter of an application of James Yate Johnson (Assignee) for leave to
amend the Specification of the said Letters Patent.
Pursuant to a determination of the Law Officer on the 12th day of November
1884, on appeal from my decision, the Specification of the said Letters Patent has
been amended in accordance with the said determination, and the amendment has
been recorded as of that date.
Dated thin noth dose
f100-

page_text: "
LETTERS PATENT to Frederick John Cheesbrough of the Office for Patents
15 Water Street Liverpool in the County of Lancaster, Consulting Engineer
for an Invention of IMPROVEMENTS IN AND RELATING TO ELECTRIC LAMPS
AND TO A METHOD OF CHARGING SUCH LAMPS WITH AN ARTIFICIAL ATMO-
SPHERE-AND-PURIFYING-THE-SAME,-AND-TO-THE-PRODUCTION-OF-A-CARBON
FOR USE IN ELECTRIC LAMPS AND FOR OTHER ELECTRIC PURPOSES com-
municated to him from abroad by William Edward Sawyer of New York
City County and State and Albon Man of Brooklyn County of Kings, State
of New York United States of America
PROVISIONAL SPECIFICATION left by the said Frederick John Cheesbrough.
at the Office of the Commissioners of Patents on the 28th November 1878.
FREDERICK JOHN CHEESBROUGH, of the Office for Patents, 15, Water Street,
Liverpool, in the County of Lancaster, Consulting Engineer. "IMPROVEMENTS
IN AND RELATING TO ELECTRIC LAMPS AND TO A METHOD OF CHARGING SUCH
LAMPS WITH AN ARTIFICIAL ATMOSPHERE, AND PURIFYING THE SAME, AND TO THE
PRODUCTION OF A CARBON FOR USE IN ELECTRIC LAMPS AND FOR OTHER ELECTRIC
PURPOSES." [A communication to him from abroad by William Edward Sawyer of
New York City County and State and Albon Man of Brooklyn County of Kings,
State of New York United States of America.]
The object of this Invention is
Firstly The production of an improved electric lamp.
Secondly a better method of charging the lamp with an artificial atmosphere
and of purifying the same.
Thirdly The production of a better carbon for the use of electric lamps and other
electric purposes.
J
The following detail description of this Invention and the improvements will
fully explain and illustrate their practical application and advantage, and in con-
clusion point out specifically of what the Invention and improvements consist,'
reference being had to the Drawing accompanying and making part of this Specifi-.
cation.
At the present day it is not new to produce a light by causing the electric current'
to heat a carbon conductor to incandescence in a vacuum, or in nitrogen, or in other:
gas; but no lamp has yet been devised, which would be practically operative, and for
these reasons:
First The methods that have been employed for charging the lamp with artificial
atmosphere, such as the displacement of mercury, water, or air by the gas, or the
combustion of phosphorus in the the lamp are imperfect. A perfect vacuum is un-
atainable; some oxygen, or other element, or compound remains in the lamp; and'
slow consumption or disintegration takes place; for the remanent gas, or vapour
other than nitrogen, oxygen forming with it carbonic acid, or oxide, which in turn
1 2

page_text: is decomposed with the result of depositing the carbon upon the globe and setting
free the oxygen to attack fresh carbon.
Second It has been found practically impossible under the varying degrees of
heat and pressure to maintain perfect joints and the result is that expansion of the
artificial atmosphere by the heat from the luminous conductor expels a portion of
the same and the contraction of the atmosphere upon cooling, causes a portion of
the external air to penetrate the globe, thus supplying oxygen, which at the next
lighting feeds upon the carbon.
Third The unequal expansion of the carbon and its holders has resulted in
fractures of the former so that, however perfect the atmosphere, in the globe, the
lamp, has never been permanent.
To obviate these several difficulties is the object of this Invention.
To charge the lamp it is preferred to employ nitrogen gas, and this is produced in
the lamp by an improved process in a state of great purity.
זי
As a safeguard against an infinitessimal leakage it is preferred to place in the
lamps a small quantity of sodium, potassium, or other agent having a great affinity
for oxygen whose oxidization, unlike the oxidization of phosphorous produces no
vapour, but a solid not easily changed by heat. As an additional safeguard it is
preferred to place in the lamps a quantity of freshly burned lime, so that any traces
of carbonic acid gas which might suffer the decomposition and depositing herein
before mentioned may be quickly absorbed and rendered harmless.
To make the lamp perfectly air tight, recourse is had to certain fittings to the
opening at the base of the globe, which will be described in detail hereinafter.
To guard against great heating and unequal expansion at the joints which would
imperil the sealing of the lamp and soon render it useless, the incandesent carbon is
isolated from the lower part of the globe, where the joints are situated by a disk, or
diaphragm of some refractory substance, preferably soapstone, or porcelain, whereby
all downward radiation of the heat is prevented, and the joints kept comparatively
cool, at the same time the upper part of the globe may be very hot.
Furthermore to prevent conduction of the heat from the incandesent carbon to
the joints by the metallic connection communicating therewith, two conductors,
leading upward from the base are arranged in a spiral volute, or fluting form, so as
to obtain considerable length of conductor in a limited space, and very little of the
heat reaches the base. By means of the several devices shown and described, a
permanently air tight lamp is obtained. The arrangement for avoiding fracture of
the carbon will be fully described hereinafter.
In the Drawings Figure 1 is a side view, and Figure 3, a partial front view of the
lamp. Figures 2, 6 and 7 are views of parts thereof. In Figures 4, 5 and 8 are
indicated possible modifications of the lamp and in Figure 9 is shown the general
arrangement of apparatus for charging the lamp with artificial atmosphere, in
which the carbon is preserved.
Referring to Figures 1 and 3 A is the glass globe, provided with a rim, or flange A¹
(better shown in Figure 6) by means of which it is clamped to the glass base, or
stopper B (better shown in Figure 7).
"
The globe is shown in the form of a tube closed at one end, but it is clear that
its shape may greatly differ from that shown. The glass may be "diamond. cut
to effect diffusion of the light, or translucent to soften it; or the globe may be sur-
rounded by a second globe possessing these characteristics, and a second globe would
in fact be necessary in a lamp placed out of doors, or subject to wetting, as the
heated globe A if unprotected, would be in great danger of breakage.
:
To the base of the globe is ground the glass stopper B (better shown in Figure 7)
with great nicety in order that the fit may be perfect.
Slipping over the top of the globe A is a brass flange L (shown partially cut
away) which bears upon the rim A¹ to bring the globe firmly down upon the
stopper B, the pressure upon the rim of the globe being softened and equalized by
the cushioned flange of wood, paper, or other, yielding substance P.

page_text: • Under the stopper B is placed first a flange of wood, or other yielding sub-
stance M. Second a flange of spring rubber N; and last a flange of brass. O, all
shown partially cut away. Through all these flanges and flange L go the bolts J J
of which there may be any number, so distributed around the circle as to equalize.
the pressure upon the rim A¹ and stopper B. The bolts J J are secured in the
usual manner by nuts K K. The flange P softens the pressure upon the rim of the
globe A, preventing fracture; the brass flange L yields to any inequalities which
may exist. The wooden flange M softens the pressure upon the stopper B pre-
venting fracture thereof, while it is unaffected by any heat that may there exist;
and the rubber flange N protected from the heat acts as a spring to yield to slight
unequal expansions and maintain a perfect contact between A and B The rubber
Bange may however be omitted and the form of the stopper-B- may be changed to
that of a stopper ground into the end of the globe A as stoppers are ground
into bottles.
In setting up the lamp the lower ground edge of the rim A¹ is slightly coated
with fur balsam or some cement, in order the better to insure that hermetical
sealing which is indispensible to the preservation of the incandesent conductor.
Through the stopper B are drilled two holes Figure 7 through which pass the
bolts QQ protected, or not by a cloth, or paper lining. These bolts are tubes, and
their function is of the greatest importance. The bolt heads are accurately fitted
to the upper surface of the stopper and under them coated with balsam or some
cement, are thin paper, or tinfoil washers ll. The nuts m m are accurately fitted
to the under surface of the stopper and under them are similar washers
similarly prepared. Thus arranged the bolts are permanently fixed to the base,
and when the lamp is charged with the artificial atinosphere required, the binding
posts n n whose set screws are o o similarly guarded by washers are set up
upon the bolts ends, whereby the lamp is hermétically sealed. Entering the bolt
heads so as to form a perfect connection with them are two tubes JK
arranged fluting volutely, or spirally as desired, the tube K being closed at the
top, but provided with an opening i, and the tube J being continuous so that com-
munication with the top of the lamp when the binding posts n n are removed is
by way of the tube J and to the base of the lamp by tube K at the point The
object of this arrangement will herein after be made apparent. C is a disk of
soap-stone, porcelain, or other refractory substance, if isolated, a metal not readily
fractured by heat which almost entirely fills the globe A at, or near the middle
thereof. This like the glass stopper B is perforated with two holes, through which
pass the metal tube H and the metal rod I both of which are provided with a
screw thread at their lower ends.. The tube H and the rod I are firmly fixed to
the disk by means of nuts ffff as will be comprehended without further
explanation.
Into the lower ends of H and I and firinly fixed thereto in any manner whatso-
ever enter the conducting tubes J and K. Let into the rod I is a short stick of
carbon D rounded at the top, which it is preferred to fasten to the rod by winding
around the two the naked wire h which may be copper, silver, or platina
Sliding up and down in the tube H is a rod F bent at right angles at the top, so
as to bring the extremity on a line above the carbon D. The rod F is prevented
form turning in the tube H by the pin d fixed to the rod and working in the
slot e.
The light is produced by the heating of the small carbon rod E at the point E¹
between the clamp G and the top of the carbon D, connection with the small
carbon E being had both through clamp G and the platina piece à on bent
rod F.
The rod F exerts a pressure upon the carbon E which continues the same with-
out regard to the length of the carbon, and thus should fracture, or slight consump-
tion of the carbon occur at the first lighting, or any subsequent lighting of the
lamps the necessity of taking down the same renewing the carbon and recharging

page_text: the globe is obviated inasmuch as the weight of the rod F gently forces the carbon
through the clamp until a new contact between E and D is established.
The construction of the clamp G is shown in Figure 2 which is a top view of the
same. It consists of a copper, or silver strip bent around the tube H and fixed to
the same either by a pin or by its own pressure. At the end of the clamp are
pinned two pieces of platina, or irridium b b which may, or may not touch each
other but each of which is slightly grooved to form an opening C through which
the carbon rod E may pass and in which it may be held in place. The cross piece
of copper g pinned to the copper, or silver strip, which constitutes the main portion
of the clamp, serves the purpose, through its expansibility of increasing and lessen-
ing the distance between the platina pieces b b according to the degree of heat
experienced thereby in a great measure avoiding fracture of the carbon at E¹ when
intensely heated by the current.
In setting up the lamp it is preferred to place inside the globe a lump of sodium,
or potassium R and one, or more lumps of freshly burned lime S, although this
Invention is not confined to the introduction of these substances, sodium and
potassium being conductors of electricity may be protected from the conductors to
the carbon if deemed necessary by enclosing the same in a bag of cloth, or in
a glass tube open at one end.
It is known that phosphorous has been placed in sealed lamps to remove the
oxygen by its slow combustion but the phosphorous acid evolved is not only fatal
to the carbon, when intensely heated, but beclouds the globe and obscures the light.
Neither sodium nor potassium exert any such deleterious influence; the product of
oxidization being a solid, incapable, under the circumstances of yielding either gas,
or vapour of any kind, hence the use of such as a safeguard in the lamp. Should
carbonic acid gas exist, or at any time be evolved in the lamp, it is quickly taken
up by the lime, or by the soda, or potassa formed by oxidization of the sodium, or
potassium.
In Figures 4 and 5 is indicated a modification of the lamp to the chandelier
form, any number of carbons D and E may be arranged around a circle in the
form shown in Figures 1 and 2. having for each a feeding device F G, the whole
being in a single globe, or the chandelier as shown may be arranged as shown in
Figure 4 U being a metal disk, provided with five, or more, or less tubes U₁ in
which slide the small carbon rods E E which are forced into contact with the
lower carbons D D by the downward pressure of rods T¹ surmounted by the
weights T T. All of the lower carbons D connect with the disk V to which is
fixed tube V¹, and through this tube and the disk, but insulated therefrom, passes
the conductor W which is attached to the upper disk U and is therefore in
connection with all the small carbons E.
In Figure 8 is indicated a modification of the single carbon lamp the clamp G
being dispensed with and the bent rod F being provided like the rod I of Figure 1
with a carbon piece X wired to it precisely as carbon D is wired to rod I.
The lamp being set up, the next important thing is to charge it with the atmo-
sphere, which will prevent consumption of the carbon, and the detail description of
the improved process of charging the lamp is as follows:
The various methods of manufacturing nitrogen gas are well known Having
dried and purified the gas until it stands all tests it is passed into a dry receiver,
preferably a bag of vulcanized rubber. Referring now to Figure 9, into a glass
tube p. p., in a furnace Z by means of which the tube may be heated to any
desired extent, is placed a quantity of sodium, or potassium, or other agent having
a great affinity for oxygen, whose oxidization produces a solid. If deemed advisable
there may be added the same purifying agent, or agents. Heat, while not essential,
greatly facilitates the operation and therefore even with potassium is is preferred
to employ the furnace. To one end of the glass tube p p by means of a flexible
tube is attached the receiver Y filled with nitrogen and having removed the
binding posts n n Figure 1 from the lamp the other end of the tube p is connected

page_text: by means of a flexible tube and nipple S with the bolt Q, which connects with
the tube J leading up to the top of the lamp.
By means of weight q a sufficient quantity of the nitrogen is forced through
the tube p and the lamp to greatly dilute and mostly displace the atmospheric air
contained therein. The empty closed receiver Y is then attached by flexible tube r
and nipple S to the, bolt Q which is connected to conductor K of the lamp and·
the lamp being now in a closed circuit of nitrogen gas, the operation of purification
begins. The gas passes slowly from the receiver Y through tube p, thence through
the tube J to the top of the lamp at the point U and thence down and outward at
the point t into the receiver Y and from Y by the reverse action it is repassed into
receiver Y. This transference is repeated until there is no further evidence of
oxidization when the receiver Y¹ being empty a pressure is exerted upon the
receiver Y and maintained so as to cause a slight escape of gas from the lamp
during the time that Y' is disconnected, and the binding post being put into the
bolt connecting with conductor K. The nipple S is lastly disconnected from the
bolt Q of tube J; and the binding post for that tube put on when the lamp is
ready for use and will remain so for an indefinite period, the lime S in the lamp
absorbing any traces of of carbonic acid gas that may be present, or evolved, and the
sodium or potassium burning out any traces of oxygen that may enter during the
closing of tube J.
By the process described the lamp may be charged with absolutely pure nitrogen
gas, and it is clear that any number of lamps may be placed in the circuit and
simultaneously charged, the gas in transference passing seriatim through the lamps
There has been shown and described an electric lamp in which a pencil of carbon
is heated to incandescence in a nitrogen, or other carbon preservative atmosphere,
one of the principal obstacles to successful electric lighting by incandesence is the
dissociated character of nearly all obtainable carbon. In most of such carbon there
is danger of fracture as well as of the establishment of the voltaic arc, and
furthermore, the carbon unless specially prepared by this process naturally occludes
sufficient air or oxygen to render its consumption a mere question of time, since as
fully set forth, the least quantity of oxygen in a sealed lamp is sufficient to combust
an indefinite quantity of carbon.
As is well known carbon suitable for electric lighting by the voltaic arc is
naturally produced in gas retorts, but generally the rods of carbon used in the
"regulator" lamps, so called, are moulded from the powdered material. Neither,
the one nor the other quality of carbon is suitable for electric lighting by incan-
desence. In both there is a lack of homogeneity. The pencil is not sufficiently
hard and dense, because in the first place, the heat required to produce the proper
character of carbon is as high as 7,000° Fahrenheit and such a temperature is not '
obtainable in the Retort; and in the second place the mechanical subdivisions of the
material and the pressure necessary to produce the perfect article are practically
unattainable Carbon of the ordinary sort when beated by the electric current'
exhibits points and lines of unequal brilliancy. Carbons prepared by this process,'
when so heated glow with a uniform brilliancy throughout!
'
It has been found that a pencil of carbon immersed in a hydro-carbon gas, or
liquid and heated to an extremely high temperature by the voltaic current is not
itself attacked but decomposes the surrounding matter the carbon of which enters
and fills up its pores to an extent impossible except with matter in a very attenu-
ated state, and deposits a perfectly homogeneous layer, generally of a bright gray
colour upon the exterior surface; as the carbon increases in size more current is
required to maintain its temperature, and if the current is gradually increased in
accordance with the demand for it, there is appearingly no limit to the increase in
mass of the homogeneous exterior deposit. Carbon pencils may be cut from this
deposit, or the original pencil with its coating may be used in the lamps.
In this process it would seem that the carbon is never in contact with the liquid in
which it is immersed but surrounded by a carbonic gas of a very high temperature
.

page_text: naptha turpentine bees-wax, balsam and most oils if pure operate satisfactorily,
almost any hydro carbon in fact will answer.
This Invention is not confined to the treatment of carbon alone, since it is obvious
that many infusible substances non conductors of electricity may be heated in
hydrocarbon liquids, or gases, so as to render them conductors of electricity, as for
instance a tube of lime enclosing a pencil of carbon' through which the electric.
current is caused to circulate.
The beforegoing is a descriptive method of charging a sealed globe with pure
nitrogen gas, let it be supposed that the pencil of carbon held between two.carbon
pieces of greater mass than that of the pencil as above described is immersed in
the hydrocarbon liquid and heated in the manner already described being then
cleansed in alcohol, the pencil and its holders without having been disturbed and
placed in the globe in which they are to be hermetically sealed.
The globe is charged, with pure nitrogen, and then while still allowing pure
nitrogen to flow into and out of the globe the carbon is heated to incandescence
thus driving out all impurities and occluded gases, which are carried out of the lamp
by the current of nitrogen.-With this operation the preparation of the carbon is
completed, and the lamp now being hermetically sealed as above described, is ready
for use.
In concluding this description the fact must be pointed out that the consolidated
homogeneous carbon of this Invention may be produced by the electro platina
process as well as by the electrical heating of a conductor in a carbon gas, or liquid.
The cathode composed either of solid carbon, or of an infusible refractory substance,
coated with plumbago or graphite is immersed in a carbon liquid and connected
with one pole of the battery. The other pole of the battery is connected with the
anode, composed of solid carbon, also immersed in the liquid. The passage of the
current decomposes the liquid and deposits a homogeneous layer of carbon upon the
cathoide.
This Invention also covers substantially the following points, or parts in combi-
nation and in détail and are intended to be embraced and included in the Invention
of which this is a Specification.
:
First An electric lamp in which the globe and stopper, both of glass, or other
vitreous substance are ground together and held together by a clamping device
Second In an electric lamp the combination with suitable conductors of electricity
of an inclosing globe provided with a rim, or flange A¹ forming an integral part of
Buch globe, as and for the purpose specified
Third The combination of the vitreous globe A of an electric lamp and the
cushion P placed as shown and described above the vitreous flange thereof for the
purpose of supporting a clamping device
:
Fourth The combination of the vitreous globe A of an electric lamp and the
cushion N, placed as shown and described under the stopper thereof for the purpose
of supporting a clamping device.
!
Fifth The combination of the globe of an electric lamp and the two cushions N
and P placed as shown and described, for the purpose of supporting a clamping
device.
Sixth In an electric lamp, a tube bolt Q and binding post n in combination with
a packing under said binding post
Seventh In an electric lamp a tube bolt Q nut m binding post n and packings
ZZZ
's
:
Eighth The combination of the clamp G and the cross piece g, as and for the
purpose specified
Ninth In an electric lamp a tube leading from an external connection to or near
to the top of the globe, and having an opening at, or near to the base of the globe,'
for the purpose of facilitating the filling of the globe with a carbon-preservative
atmosphere, substantially as shown and described ..

page_text: Tenth In an electric lamp two unobstructed tubes leading from external connec-
tions into the globe thereof and so arranged as to facilitate the charging of the globe
with a carbon preservative atmosphere.
:
J
Eleventh In an electric lamp a diaphragm obstructive of radiant heat, interposed
between the luminous part, or parts of such lamp and the air tight joint, or joints
thereof, as and for the purpose specified
Twelfth An electric lamp within which the conductors, leading from the air tight
joint, or joints thereof to the luminous part, or parts thereof are so formed, length-
ened, or broadened as to have great radiating surface, so that the conduction of heat
from such part, or parts to such joint, or joints is in great measure if not wholly
prevented
}
Thirteenth In an electric lamp the long coiled conductor J opening at its upper
end and connecting with one electrode of such lamp.
Fourteenth In an electric lamp the long coiled conductor K opening at the base
of such lamp, and connecting with one electrode thereof.
Fifteenth In an electric lamp an absorbent of carbonic acid gas.
Sixteenth In the sealed globe of an electric lamp containing an ozotic, or other
carbon preservative atmosphere an absorbent of carbonic acid gas.
Seventeenth In an electric lamp an agent having a great affinity for oxygen
whose oxidization produces a solid unalterable by the natural heat in the lamp, such
as sodium, or potassium
Eighteenth The combination in an electric lamp of an absorbent of carbonic acid
gas and an agent having a great affinity for oxygen, whose oxidization produces a
solid unalterable by the natural heat in the lamp, such as sodium, or potassium.
Nineteenth A carbon, rod, piece, or pencil heated to incandesence in an atino-
sphere deprived of oxygen in which atmosphere is permanently an oxidizing agent
whose oxidization produces a solid, which agent may be sodium, or potassium, or
other readily oxidizable metal.
Twentieth A carbon rod piece, or pencil heated to incandesence in an atmosphere
deprived of oxygen in which atmosphere is permanently an absorbent of carbonic
acid gas
Twenty first A carbon rod, piece, or pencil, heated to incandesence in an atmo-
sphere deprived of oxygen in which atmosphere is permanently an oxidizing agent,
such as sodium, potassium, or other readily oxidizable metal in combination with an
absorbent of carbonic acid gas.
Twenty second A sealed electric lamp enclosing an agent, or agents for purifying
the atmosphere contained therein from oxygen, or oxygenic gases.
Twenty third The hereinbefore described method of charging an electric lamp
with a carbon preservative atmosphere, consisting in placing the lamp in the circuit
of a purifying agent, or agents, and two gas receivers one of which is primarily
preferably filled with the carbon preservative gas and the other empty and forcing
the gas back and forth from one receiver to the other, each time through the
lamp and the purifying agent, or agents until the atmosphere becomes pure, or
nearly so.
Twenty fourth The hereinbefore described method of charging an electric lamp
with a carbon preservative atmosphere, consisting in placing the lamp in a circuit
of a purifying agent, or agents and two receivers one of which is primarily prefer-
ably filled with a gaseous medium and the other empty, and forcing the gaseous
medium back and forth from one receiver to the other each time through the lamp
and the purifying agent, or agents until the atmosphere in the lamp becomes pure
or nearly so.
Twenty fifth The method of charging an electric lamp with a carbon preserva-
tive gas by intermittently passing a purified atmosphere, or an atmosphere under-
going purification into the globe thereof, and thereby successively diluting and
purifying the contents thereof, until finally all or nearly all the oxygen is removed
therefrom,

page_text: Twenty sixth The herein described method of preparing the illuminating part
of an electric lamp consisting of electrically heating the same, while it is surrounded
by a carbon gas, or liquid.
Twenty seventh A material for the manufacture of the illuminating conductors
of electric lamps, produced by electrically heating carbon in a carbon gas.
Twenty eighth The illuminating part of an electric lamp consisting of carbon
deposited by electric action.
Twenty ninth A material for the manufacture of the illuminating conductors of
electric lamps produced by electric action.
Thirtieth The hereinbefore described method of preparing the illuminating part
of an electric lamp consisting in first obtaining a solid deposit of carbon by electric
action as set forth, and subsequently when the globe containing it is charged with
a carbon preservative atmosphere, before the flow of such preservative atmosphere
through the lamp has ceased and before the lamp is finally sealed, heating the
illuminating part by means of the electric current, in order to expel impurities and
occulder gases

page_text: FREDERICK JOHN CHEESBROUGH, of the Office for Patents, 15 Water Street,
Liverpool, in the County of Lancaster, Consulting Engineer "IMPROVEMENTS
IN AND RELATING TO ELECTRIC, LAMPS AND TO A METHOD OF CHARGING SUCH
LAMPS WITH AN ARTIFICIAL ATMOSPHERE AND PURIFYING THE SAME AND TO THE
PRODUCTION OF A CARBON FOR USE IN ELECTRIC LAMPS AND-FOR-OTHER-ELECTRIC
PURPOSES "A communication to me from abroad by William Edward Sawyer of
New York City, County and State and Albon Man, of Brooklyn, County of Kings,
State of New York, United States of America.
The object of this Invention is
Firstly The production of an improved electric lamp
Secondly A better-method-of-charging the lamp with an artificial atmosphere
and of purifying the same
Secondly Thirdly The production of a better carbon for the use of electric
lamps and other-electric-purposes
The following detail description of this Invention and improvements will fully
explain and illustrate their practical application and advantage, and in conclusion
point-out-specifically of what the Invention and improvements consist, reference
being had to the Drawing accompanying and making part of this Specification.
At the present day it is not new to produce a light by causing the electric current
to heat a carbon conductor to incandescence in a vacuum, or in nitrogen, or in other
gas; but no lamp has yet been devised, which would be practically operative, and
for these reasons:
First The methods that have been employed for charging the lamp with artificial
atmosphere, such as the displacement of mercury, water, or air by the gas, or the
combustion of phosphorous in the lamp are imperfect. A perfect vacuum is unattain-
able; some oxygen, or other element, or compound remains in the lamp, and slow
consumption or disintegration takes place, for the remanent gas, or vapour, other
than nitrogen, oxygen forming with it, carbonio neid, or oxide, which in tum is
decomposed with the result of depositing the carbon upon the globe and setting
free the oxygen-to-attack-fresh-carbon.
Second It has been found practically impossible under the varying degrees of
heat and pressure to maintain perfect joints and the result is that expansion of the
artificial-atmosphere by the heat from the luminous conductor expels a portion of
the same and the contraction of the atmosphere-upon-cooling, causes a portion of
the external air to penetrate the globe, thus supplying oxygen, which at the next
lighting-feeds upon the carbon.

page_text: Second Third The unequal expansion of the carbon and its holders, has
resulted in fractures of the former so that however perfect the atmosphere in the
globe the lamp has never been permanent.
To obviate these several difficulties is the object of this Invention
To charge the lamp it is preferred to employ nitrogen gas, and this is produced in
the lamp by an improved process in a state of great purity.
As a safeguard against an infinitesimal infinitessmal leakage it is preferred to
place in the lamps a small quantity of sodium, potassium, or other agent having a
great affinity for oxygen, whose oxidization, unlike the oxidization of phosphorous,
produces no vapour, but a solid not easily changed by heat. As an additional safe-
guard it is preferred to place in the lamps a quantity of freshly burned lime, so
that any traces of carbonic acid gas which might suffer the decomposition and
depositing hereinbefore mentioned may be quickly absorbed and rendered harmless.
To make the lamp perfectly air tight, recourse is had to certain fittings to the
opening at the base of the globe, which will be described in detail hereinafter.
To guard against great heating and unequal expansion at the joints which would
imperil the sealing of the lamp and soon render it useless, the incandescent carbon
is isolated from the lower part of the globe, where the joints are situated by a disk,
or diaphragm of some refractory substance, preferably soap-stone, or porcelain,
whereby all downward radiation of the heat is prevented, and the joints kept com-
paratively cool, at the same time the upper part of the globe may be very hot.
Furthermore to prevent conduction of the heat from the incandescent carbon to
the joints by the metallic connection communicating therewith, two conductors,
leading upward from the base are arranged in a spiral volute, or fluting form, so as
to obtain considerable length of conductor in a limited space, and very little of the
heat reaches the base. By means of the several devices shown and described, a
permanently air tight lamp is obtained. The arrangement for avoiding fracture of
the carbon will be fully described hereinafter.
In the Drawings accompanying this Specification Figure 1 is a side view, and
Figure 3 a partial front view of the lamp. Figures 2, 6 and 7 are views of parts
thereof. In Figures 4, 5 and 8 are indicated possible, modifications of the lamp,
and in Figure 9 is shown the general arrangement of apparatus for charging the
lamp with artificial atmosphere, in which the carbon is preserved.
Referring to Figures 1 and 3 A is the glass globe, provided with a rim, or flange A¹
(better shown in Figure 6), by means of which it is clamped to the glass base, or
stopper B (better shown in Figure 7).
The globe is shown in the form of a tube closed at one end, but it is clear that its
shape may greatly differ from that shown. The glass may be "diamond cut" to
effect diffusion of the light or translucent to soften it or the globe may be sur-
rounded by a second globe possessing these characteristics, and a second globe
would in fact be necessary in a lamp placed out of doors, or subject to wetting, as
the heated globe A if unprotected, would be in great danger of breakage.
To the base of the globe is ground the glass stopper B (better shown in Figure 7)
with great nicety in order that the fit may be perfect.
Slipping over the top of the globe A is a brass flange L (shown partially cut
away) which bears upon the rim A¹ to bring the globe firmly down upon the
stopper B, the pressure upon the rim of the globe being softened and equalized by
the cushioned flange of wood, paper, or other yielding substance P.
Under the stopper B is placed first a flange of wood, or other yielding substance M.
Second a flange of spring rubber N; and last a flange of brass O, all shown par-
tially cut away. Through all these flanges and flange L go the bolts jj of which
there may be any number, so distributed around the circle as to equalize the pressure
upon the rim A¹ and stopper B. The bolts j; are secured in the usual manner
by the nuts kk. The flange P softens the pressure of the globe A¹, pre-
venting fracture; the brass flange L yields to any inequalities which may exist.
The wooden flange M softens the pressure upon the stopper B preventing fracture

page_text: -
thereof, while it is unaffected by any heat that may there exist; and the rubber
flange N protected from the heat acts as a spring to yield to slight unequal expan
sions and maintain a perfect contact between A and B.. The rubber flange may
however be omitted and the form of the stopper B may be changed to that of a
stopper ground into the end of the globe A as stoppers are ground into bottles.
In setting up the lamp the lower ground edge of the rim A' is slightly coated
with fir balsam fur balsum, or other cement in order the better to insure that
hermetical sealing which is indispensible to the preservation of the incandescent
conductor.
Through the stopper B are drilled two holes Figure 7 through which pass the
bolts QQ protected, or not by a cloth, or paper lining. These bolts are tubes, and
their function is of the greatest importance. The bolt heads are accurately fitted
to the upper surface-of-the-stopper and-under them-coated-with balsam, or some
cement are thin paper, or tin foil washers . The nuts m m are accurately fitted
to the under surface of the stopper and under them are similar washers / similarly,
prepared. Thus arranged the bolts are permanently fixed to the base, and when
the lamp is charged with the artificial atmosphere required, the binding posts n n,
whose set screws are 00 similarly guarded by washers are set up upon the
bolt ends, whereby the lamp is hermetically sealed. Entering the bolt heads QQ
so as to form a perfect connection with them, are two tubes J, K arranged fluting
volutely, or spirally as desired the tube K being closed at the top, but provided
with an opening i, and the tube J being continuous so that communication with
the top of the lamp when the binding posts n n are removed is by way of the
tube J and to the base of the lamp by tube K at the point i. The object of this
arrangement will hereinafter be made apparent. C is a disc of soap stone, porcelain,
or other refractory substance, if isolated, a metal not readily fractured by heat
which almost entirely fills the globe A at, or near the middle thereof. This like the
glass stopper B is perforated with two holes, through which pass the metal tube H
and the metal rod I both of which are provided with a screw thread at their lower
ends. The tube H and the rod I are firmly fixed to the disk by means of nuts ƒƒfƒ
as will be comprehended without further explanation.
Into the lower ends of H and I and firmly fixed thereto, in any manner what-
soever enter the conducting tubes J and K. Let into the rod I is a short stick of
carbon D rounded at the top; which it is preferred to fasten to the rod by winding
around the two the naked wire h, which may be copper, silver, or platina.
Sliding up and down in the tube H is a rod F bent at right angles at the top, s0
as to bring the extremity on a line above the carbon D. The rod F is prevented
from turning in the tube H by the pin d'fixed to the rod and working in the
slot e.
The light is produced by the heating of the small carbon rod E at the point E
between the clamp G and the top of the carbon D, connection with the small
carbon E being had both through clamp G and the platina piece a on bent rod F.
The rod F exerts a pressure upon the carbon E, which continues the same without
regard to the length of the carbon, and thus should fracture, or slight consumption
of the carbon occur at the first lighting, or any subsequent lighting of the lamps
the necessity of taking down the same, renewing the carbon and recharging the
globe is obviated inasmuch as the weight of the rod F gently forces the carbon
through the clamp until a new contact between E and D is established.
The construction of the clamp G is shown in Figure 2, which is a top view of the
same. It consists of a copper, or silver strip bent around the tube H and fixed to
the same either by a più, or by its own pressure. At the end of the clamp are
pinned two pieces of platina, or iridium b b, which. may, or may not touch each
other, but each of which is slightly grooved to form an opening c through which
the carbon rod E may pass, and in which it may be held in place. The cross piece
5. of copper g pinned to the copper, or silver strip, which constitutes the main portion
of the clamp serves the purpose, through its expansibility of increasing and lessening
the distance between the platina pieces b b according to the degree of heat

page_text: experienced, thereby in a great measure avoiding fracture of the carbon at E¹ when
intensely heated by the current.
In setting up the lamp it is preferred to place inside the globe a lump of sodium,
or potassium R and one, or more lumps of freshly burned lime S, although this
Invention is not confined to the introduction of these substances, sodium and
potassium being conductors of electricity may be protected from the conductors to
the carbon if deemed necessary by enclosing the same in a bag of cloth, or in a
glass tube open at one end.
It is known that phosphorous has been placed in sealed lamps to remove oxygen
by its slow combustion, but the phosphorous acid evolved is not only fatal to the
carbon, when intensely heated, but beclouds the globe and obscures the light.
Neither sodium nor potassium exert any such deleterious influence; the product of
oxidization being a solid, incapable, under the circumstances of yielding either gas,
or vapour of any kind, hence the use of such, as a safeguard in the lamp. Should
carbonic acid gas, exist, or at any time be evolved in the lamp, it is quickly taken
up by the lime, or by the soda, or potassa formed by oxidization of the sodium, or
potassium.
'
In Figures 4 and 5 is indicated a modification of the-lamp to the chandelier
form, any number of carbons D and E may be arranged around a circle in the form
shown in Figures 1 and 2, having for each a feeding device F G, the whole being
in a single globe, or the chandelier as shown may be arranged as shown in Figure 4,
U being a metal disk, provided with five, or more, or less tubes U¹, in which slide
the small carbon rods E E which are forced into contact with the lower carbons
1 D by the downward pressure of rods T¹ surmounted by the weights T T. All of
the lower carbons D connect with the disk V to which is fixed tube V¹, and through
this tube and the disk, but insulated therefrom, passes the conductor W which is
attached to the upper disk U and is therefore in connection with all the small
carbons E.
In Figure 8 is indicated a modification of the single carbon lamp, the clamp G
being dispensed with and the bent rod F being provided like the rod I of Figure 1
with a carbon piece X wired to it precisely as carbon D is wired to rod I.
The lamp being set up, the next important thing is to charge it with the atmo-
sphere, which will prevent consumption of the carbon and the detail description of
the improved process of charging the lamp is as follows:
The various methods of manufacturing nitrogen gas are well known. Having
dried and purified the gas until it stands all tests it is passed into a dry receiver,
preferably a bag of vulcanized rubber. Referring now to Figure 9, into a glass
tube p p, in a furnace Z by means of which the tube may be heated to any desired
extent, is placed a quantity of sodium, or potassium, or other agent having a great
If deemed advisable
affinity for oxygen, whose oxidization produces a solid.
there may be added the same purifying agent, or agents. Heat, while not essential,
greatly facilitates the operation and therefore even with potassium it is preferred
to employ the furnace. To one end of the glass tube p p by means of a flexible
tube is attached the receiver y filled with nitrogen and having removed the
binding posts n n Figure 1 from the lamp the other end of the tube p is con-
nected by means of a flexible tuber and nipple S with the bolt Q, which connects
with the tube J leading up to the top of the lamp.
By means of weight q a sufficient quantity of the nitrogen is forced through the
tube p and the lamp to greatly dilute and mostly displace the atmospheric air
contained therein. The empty closed receiver Y is then attached by a flexible tube
r and nipple S to the bolt Q which is connected to conductor K of the lamp, and
the lamp being now in a closed circuit of nitrogen gas the operation of purification
begins. The gas passes slowly from the receiver Y through tube p, thence through
the tube J to the top of the lamp at the point U and thence down and outward at
the point t into the receiver Y and from Y by the reverse action it is repassed into
receiver Y. This transference is repeated until there is no further evidence of
oxidization, when the' receiver Y₁ being empty a pressure is exerted upon the

page_text: receiver Y and maintained so as to cause a slight escape of gas from the lamp
during the time that Y' is disconnected, and the binding post being put into the
bolt connecting with conductor K. The nipple S is lastly disconnected from the
bolt of tube J; and the binding post for that tube put on when the lamp is
ready for use and will remain so for an indefinite period, the lime S in the lamp
absorbing any traces of carbonic acid gas that may be present, or evolved, and the
sodium, or potassium burning out any traces of oxygen that may enter during the
closing of tube J.
By the process described the lamp may be charged with absolutely pure nitrogen
gas, and it is clear that any number of lamps may be placed in the circuit and
simultaneously charged, the gas in transference passing seriatim through the
lamps.
There has been shown and described an electric lamp in which a pencil of carbon is
heated to incandescence in a nitrogen, or other carbon preservative atinosphere, one
of the principal principle obstacles to successful electric lighting by incandescence is
the dissociated character of nearly all obtainable carbon. In most of such carbon there
is danger of fracture as well as of the establishment of the voltaic arc, and further-
more, the carbon unless specially prepared by this process naturally occludes
sufficient air, or oxygen to render its consumption a mere question of time, since as
fully set forth the least quantity of oxygen in a sealed lamp is sufficient to combust
an indefinite quantity of carbon.
As is well known carbon suitable for electric lighting by the voltaic arc is
naturally produced in gas retorts, but generally the rods of carbon used in the
regulator lamps so called are moulded from the powdered material. Neither the
one, nor the other quality of carbon is suitable for electric lighting by incandescence.
In both there is a lack of homogeneity. The pencil is not sufficiently hard and
dense, because in the first place, the heat required to produce the proper character
of carbon is as high as 7,000° Fahrenheit and such a temperature is not obtainable'
in the retort; and in the second place the mechanical subdivisions of the material
and the pressure necessary to produce the perfect article are practically unattainable.,
Carbon of the ordinary sort when heated by the electric current exhibits points and
lines of unequal brilliancy. Carbons prepared by this process, when so heated glow.
with a uniform brilliancy throughout.
It has been found that a pencil of carbon immersed in a hydro-carbon gas, or
liquid and heated to an extremely high temperature by the voltaic current is not..
itself attacked but decomposes the surrounding matter the carbon of which enters
and fills up its pores to an extent impossible except with matter in a very
attenuated state, and deposits a perfectly homogeneous layer, generally of a bright
gray colour upon the exterior surface, as the carbon increases in size more current,
is required to maintain its temperature, and if the current is gradually increased
in accordance with the demand for it, there is appearingly no limit to the increase
in mass of the homogeneous exterior deposit. Carbon pencils may be cut from this
deposit, or the original pencil with its coating may be used in the lamps.
In this process it will be seen that the carbon is never in contact with the liquid
in which it is immersed but surrounded by a carbonic gas of very high temperature,
bees wax, balsam and most oils if pure, operate satisfactorily, almost any hydro-
carbon in fact will answer.
This Invention is not confined to the treatment of carbon alone, since it is
obvious that many infusible substances non conductors of electricity may be heated*
in hydro carbon liquids, or gases so as to render them conductors of electricity as
for instance a tube of lime enclosing a pencil of carbon through which the electric
current is caused to circulate.
The beforegoing is a descriptive method of charging a sealed globe with pure.
nitrogen gas, let it be supposed that the pencil of carbon held between two carbon
pieces of greater mass than that of the pencil as above described, is immersed in,
the bydrocarbon liquid and heated in the manner already described, being then

page_text: cleansed in alcohol, the pencil and its holders without having been disturbed and
are placed in the globe in which they are to be hermetically sealed.
The globe is charged with pure nitrogen, and then while still allowing, pure.
nitrogen to flow into and out of the globe, the carbon is heated to incandescence.
thus driving out, all impurities and occluded gases, which are carried out of the
lamp by the current of nitrogen. With this operation the preparation of the
carbon is completed and the lamp now being hermetically, sealed as above described;
is ready for use.
In concluding this description the fact must be pointed out that the consolidated
homogeneous carbon of this Invention may be produced by the electro platina
process as well as by the electrical heating of a conductor in a carbon gas, or liquid..
The cathode composed either of solid carbon, or of an infusible refractory substance
coated-with-plumbago, or graphite is immersed in-a-carbon-liquid-and-connected
with one pole of the battery. The other pole of the battery is connected with
the anode composed of solid carbon, also immersed in the liquid. The passage
of the current decomposes the liquid and deposits a homogeneous layer of carbon
upon the cathoide.
This Invention-also-covers substantially the following-points, or parts in com
bination--and--in-detail--and--are intended to be embraced and included in this
Invention of which this is a specification..
First An-electric lamp in which the globe and stopper, both of glass, or other
vitreous substance, are-ground-together-and-held-together-by-a-clamping-device.
Second in an electric-lamp--the--combination--with-suitable-conductors--of
electricity, of an enclosing globe provided with a rim, or flange-A' forming an
integral-part-of-such globe, as and for the purpose specified.
Third The combination of the vitreous globe A of an electric lamp and the
oushion P-placed-as-shown and described above the vitreous-flange-thereof-for-the
purpose of supporting a clamping device.
Fourth The combination of the vitreous globe A-of an electric lamp and the
oushion N-placed-as-shown and described under the stopper thereof for the purpose
of supporting a clamping device.
Fifth The combination of--the-globe of an electric-lamp and the two-oushions
N and P placed as shown and-described, for the purpose of supporting a clamping
device.
Sixth--In--an--electric-lamp, a tube-bolt Q-and-binding post-n-in-combination
with-a-packing-l-under-caid-binding post.
Seventh In an electric lamp a tube bolt Q, nut-m, -binding post--n--and
packings-1-1-1.
Eighth The combination-of-the-clamp G and the cross-piece-gr-as-and for the
purpose-specified.
Ninth-in-an-electric lamp a tube leading from an external connection, to, or
near-to-the-top-of the globe, and having an opening-at, or near-to-the-base-of-the
globe, for the purpose-of-facilitating the filling of the globe with a carbon
preservative atmosphere, substantially-as-shown-and-described.
Tenth In--an-electric--lamp--two--unobstructed--tubes leading from--external
connections-into-the-globe-thereof and-so-arranged as to facilitate the charging of
the globe-with-a-carbon preservative-atmosphere.
Eleventh-in-an-electrio-lamp-a-diaphragm obstructive of radiant heat, interposed
between the-luminous-part, or parts of such lamp-and-the-air-tight joint, or joints
thereof as-and-for-the-purpose-specified.
Twelfth An electric lamp within which the conductors, leading from-the-air
tight-joint, or joints thereof to the luminous part-or-parts-thereof-are-so-formed,
lengthened, or broadened-as-to-have-great radiating-surface,-so-that-the-conduction,
of heat from such part, or parts to such joint, or joints is in great measure-if not
wholly prevented.
Thirteenth-in-an-electric lamp the long-coiled-conductor J opening-at-its-upper
end-and-connecting with one-electrode-in-such-lamp.
(If

page_text: Fourteenth In an electric lamp the long coil conductor K-opening at the base
of such lamp-and-connecting with one-electrode-thereof.
Fifteenth In-an-electric-lamp-an-absorbent of carbonio-neid gas.
Sixteenth In the sealed globe of an electric lamp-containing an ozotic, or other
carbon preservative atmosphere an absorbent of carbonio-acid gas.
Seventeenth In-an electric lamp an agent having a great affinity for oxygen,
whose oxidization-produces a solid, unalterable by the natural heat in the lamp,
such as sodium, or-potassium.
Eighteenth-The combination in an electric lamp of an absorbent of carbonic acid
gas and an agent having a great-affinity for oxygen, whose-oxidization produces-a
solid-unalterable-by-the-natural-heat-in-the-lamp, such as-sodium, or potassium.
Nineteenth--A--carbon, rod, piece, -or-peneil heated to incandescence in an
atmosphere-deprived of oxygen in which atmosphere is permanently-an-oxidizing
agent whose oxidization produces a solid, which agent may be sodium, or potassium,
or other readily-oxidizable-metal.
Twentieth A carbon-rod, piece, or pencil-heated to incandescence in an atmo
sphere-deprived of oxygen in which atmosphere-is permanently-an-absorbent of
carbonic acid-gas.
Twenty-first A-carbon--rod, piece, -or-pencil- heated--to-incandescence in an
atmosphere-deprived of oxygen-in-which-atmosphere-is-permantently an oxidizing
agent, such-as-sodium, potassium, or other readily oxidizable metal-in-combination
with-an-absorbent-of-carbonie-acid-gas.
Twenty-second A-sealed electric-lamp-enclosing an agent, or agents for purifying
the atmosphere-contained therein-from-oxygen, or oxygenie gases.
Twenty-third The herein before described-method of charging-an-electric-lamp
with-a-carbon preservative-atmosphere, consisting in placing the lump in the circuit
of a purifying agent,-or-agents and two gas receivers, one of which is primarily
preferably filled--with-the-carbon-preservative-gas--and the other--empty--and
forcing the gas-back-and-forth from one-receiver to the other, each time through
the lamp-and-the-purifying agent, or agents-until the-atmosphere becomes pure, or
nearly-so.
Twenty-fourth The herein before-described method of charging an electrio-lamp
with-a-carbon-preservative atmosphere, consisting in placing the lamp-in-a-eirouit
of a purifying agent, or agents and two-receivers, one of which is primarily
preferably filled with a gaseous--medium and the other empty, and foreing the
gaseous medium-back-and-forth-from-one-receiver to the other-each-time through
the lamp and the purifying agent, or agents until the atmosphere in the lamp
becomes-pure, or nearly-co.
Twenty fifth The method of charging-an-electric-lamp-with-a-carbon--pre-
servative gas by intermittently passing a purified atmosphere, or an atmosphere
undergoing purification into the globe thereof, and thereby successively-diluting
and purifying the contents thereof, until finally all, or nearly all the oxygen is
removed-therefrom.
I do not claim the construction of the Lamp hereinbefore described but what
I do claim is :-
First. Twenty-sixth The herein described method of preparing the illuminating
part of an electric lamp consisting of electrically heating the same, while it is
surrounded by a carbon gas, or liquid.
Second Twenty seventh A. material for the manufacture of the illuminating
conductors of electric lamps, produced by electrically heating carbon in a carbon gas.
Twenty-eighth The illuminating part of an electric lamp consisting of carbon
deposited by-electrie-action.
Twenty-ninth-A-material for the manufacture-of-the-illuminating-conductors of
electrie-lamps-produced by electric-action.
Third Thirtieth The herein before described method of preparing the illuminating
part of an electric lamp consisting in first obtaining a solid deposit of carbon by

page_text: electric action as set forth, and subsequently when the globe containing it is charged
with a carbon preservative atmosphere, before the flow of such preservative
atmosphere through the lamp has ceased and before the lamp is finally sealed,
heating the illuminating part by means of the electric current, in order to expel
impurities and occluded ecoulder gases.
In witness whereof, I the said Frederick John Cheesbrough have hereunto set
my hand and seal this Twenty fourth day of May, in the year of our Lord One
thousand eight hundred and seventy nine.
FREDERICK JOHN CHEESBROUGH. (L.S.)