Year: 1899

page_text: Date of Application, 20th Feb., 1899
Complete Specification Left, 20th Dec., 1899-Accepted, 20th Feb., 1900
A communication from abroad by HECTOR A. MACDONALD at present residing in
Paris in the Republic of France, Artist.
I. JAMES GRIEVE LORRAIN, M.I.E.E., M.I.Mech. E., of Norfolk House, Victoria
Embankment, London W.C., in the County of Middlesex, Chartered Patent Agent,
do hereby declare the nature of this invention (as communicated to me from
abroad) to be as follows:-
In this invention a refractory conductor, that is to say a conductor of the type
which is a bad conductor when cold and a good conductor when hot such for
example as magnesia, kaolin, columbin, porcelain or the like is employed in
conjunction with a good or non-refractory conductor such for example as metal
or carbon or with a semi-refactory conductor such for example as carbon mixed
with a refractory base as lime, magnesia, earth or clay or the like. The invention
also relates to suitable terminals or terminal parts.
The refractory conductor and the non-refractory (or semi-refractory) conductor
are placed in contact with or in close proximity to one another and in such
manner that when the electric current is switched on it shall flow through the
non-refractory or semi-refractory conductor, as the case may be, and so produce
such a rise of temperature therein that heat will be communicated to the re-
fractory conductor so as to raise the conductivity of the latter to a sufficient
degree to render it a sufficiently good conductor to allow sufficient current to
pass through it to raise it to incandescence and cause it to emit light.
In order that the nature of this invention may be more readily understood,
certain forms thereof will now be briefly referred to as types or examples.
In one form of the invention the refractory conductor (hereinafter termed the
incandescer) is made of elongated (preferably) form such as a bar, blade, rod,
cylinder or tube or the like, upon which a layer of non-refractory conducting
material (hereinafter termed the igniter) such as copper or carbon is deposited
or laid or along in or around which a non-refractory conductor is placed or
arranged. When the current is switched on it passes through the non-refractory
conductor or igniter raising it to incandescence and causing it to be consumed.
The heat from the non-refractory conductor or igniter is conveyed to the refractory
conductor or incandescer and so increases its electrical conductivity as to cause
the current to flow through it so that it may be raised to and maintained at
incandescence and give out light as long as the current passes through it.
Another form of the invention differs from that described in that a semi-
refractory conductor is employed as an igniter instead of the non-refractory con-
ductor and answers the same purpose.
In another form of the invention the temperature of the incandescer is raised
by means of an are passing between two parts of the igniter which latter may
be divided for the purpose. Such division may however be only partial so as
to leave a bridging part which will serve as an electrical connection between the

page_text: divided parts of the igniter and so that when the current is switched on this
bridging part will be heated and consumed, when an are will be established
between the two parts of the igniter, the said are heating the incandescer to
the required temperature. To allow for any increased consumption, or destruction
of the incandescer by the said are whilst the arc lasts, it, the incandescer, may
be thickened at the part where the arc is established.
In order to ensure good contact between the terminals of the lamp in which the
incandescer is placed and the incandescer itself the igniter is greatly thickened
at the parts where connection is made. This may be done by casting or depositing
a considerable mass of metal at such parts or by otherwise attaching metallie
or other suitable conducting masses thereto.
A combined incandescer and igniter with suitable terminal parts as herein-
before referred to constitutes a readily replaceable and renewable device for
insertion between the terminals of a lamp.
The composition of the incandescer may be varied to suit the requirements of
the case.
Thus, when a very brilliant light is desired the incandescer may be
made of material which is somewhat rapidly disintegrated during incandescence
so as to give off a kind of flame. Or, if an incandescer with prolonged life is
desired it can be made of a material which will disintegrate or change less during
incandescence but which will give out less light.
The invention contemplates, amongst others, the following constructions:-
A tubular incandescer concentric with a metallic igniter, a tubular incandescer
concentric with a carbon igniter, a cylindrical incandescer with an igniter con-
sisting of metal electro-deposited on said incandescer, a cylindrical incandescer
with a concentric carbon igniter surrounding it, the said carbon being cut away
except at a bridging part so that the two divided carbon tubes may serve as
electrodes between which an arc is established.
Dated this 20th day of February 1899.
J. G. LORRAIN,
Communicatec.
Improvements in or connected with Electric Incandescent Lamps.
A communication from abroad by HECTOR A. MACDONALD, at present residing in
Paris, in the Republic of France, Artist.
I. JAMES GRIEVE LORRAIN, M.I.E.E., M.I.Mech. E., of Norfolk House, Victoria
Embankment, London W.C., in the County of Middlesex, Chartered Patent Agent,
do hereby declare the nature of this invention (as communicated to me from
abroad) and in what manner the same is to be performed, to be particularly de-
scribed and ascertained in and by the following statement:-
In this invention a refractory conductor, that is to say a conductor of the type
which is a bad or non-conductor when cold and a good conductor when hot, such
for example as magnesia, kaolin, columbin, porcelain or the like, is employed in
conjunction with a good or non-refractory conductor, such, for example, as metal
or carbon, or with a semi-refractory conductor such for example as carbon mixed
with a refractory base as lime, magnesia, earth or clay or the like.
The refractory conductor (hereinafter called the incandescer), and the non-
refractory (or semi-refractory) conductor (hereinafter termed the igniter), are
placed in contact with or in close proximity to one another, and in such manner
that when the electric current is switched on it shall flow through the igniter

page_text: and so produce such a rise of temperature therein that heat will be communicated
to the incandescer so as to raise the conductivity of the latter to a sufficient
degree to allow sufficient current to pass through it to raise it to incandescence
and cause it to emit light.
In order that the invention may be more readily understood I have appended
hereto certain drawings which illustrate how the invention is to be, or may be,
carried into effect.
In these drawings similar numerals of reference indicate similar parts, the
Figures in Sheets 1 and 2 being chiefly shown on an enlarged scale. For sim-
plicity of illustration the figures have been made as diagrammatic as is consistent
with clear interpretation.
Figure I is a form of couple consisting of combined incandescer and igniter
part of that igniter being shown as removed from the incandescer.
Figures II, III and IV show similar combined incandescers and igniters but
with different forms of terminal parts.
Figure shows a different type of the invention.
Figure VI shows the form of couple or combined igniter and incandescer
illustrated in Figure V as placed in operative position in a lamp and with an
automatic contact or cut-out or circuit changer.
Figures VII and VIII are details of same.
Figures IX and X are respectively a longitudinal and a cross section of a form
of couple in which a divided igniter is employed.
Figures XI, XII and XIII are respectively a side elevation, a cross section
and an under plan of a form of couple in which the igniter is partially divided.
Figure XIV is a form of couple similar to that shown in Figure XI but with
terminal parts.
Figure XV is a cross section on the line of Figure XIV.
Figure XVI shows a couple having another form of partially divided igniter.
Figure XVII is a cross section on the line y-y of Figure XVI.
Figure XVIII is a side elevation corresponding with Figure XI except that
the incandescer has an enlarged part as will be hereinafter explained.
Figure XIX is a cross section on the line of Figure XVIII.
Figure XX is a longitudinal section of a form slightly different from that shown
in Figure XVIII.
Figure XXI is a side elevation of an are igniting form of the invention.
Figure XXII is an end elevation of the same.
Figures XXIII and XXIV show in two operative positions a modified form.
Referring to Figure I, the incandescer 1 consists of a wire or cylinder of
refractory material surrounded by the igniter 2 in the form of a coating necessarily
of hollow or tubular shape. This coating may conveniently be formed of carbon
or of metal electro-deposited upon the incandescer. When the said igniter con-
sists of carbon it may be formed or placed upon the incandescer or the incandescer
placed within the carbon tube after the manner in which cored carbons are
manufactured. If the igniter be of metal such for example as copper it may be
deposited by any convenient known way of depositing metal upon a non-conduct-
ing material, as for example by first placing a thin coating of graphite or the like
upon the incandescer and thereafter depositing the metal in an electro-depositing
bath.
When a combined incandescer and igniter is placed in circuit with a suitable
source of current the said current will flow through the igniter, heating it to such
a temperature that heat will be communicated to the incandescer, which latter,
when it has attained a suflicient temperature, will take the current and act as
a conductor giving out light, whilst the igniter will gradually become burned
away and be vapourized, assuming it to be heated in free air.
After the igniter
is so removed the incandescer will continue to glow with a steady light. Such a
combined incandescer and igniter may be mounted in an exhausted bulb as in
the case of ordinary incandescent lamps although the main advantages of this

page_text: form of the invention will only be apparent when used in free air. When this
form of the invention is used in living-rooms or indoors the igniter should be
of carbon or of carbon mixed with refractory material; but when the invention
is used in the open air, as in streets, harbours or the like, the igniter may consist
of a metallic coating as copper. The incandescer 1 need not be a solid cylinder
as shown in Figure I, it may be for example of prismatic form and hollow or
tubular. The thickness of the carbon or other deposited igniter depends upon
the mass of refractory conductor (incandescer) to be heated. The smaller the
diameter of the incandescer, when the latter is a rod or cylinder, and the thinner
the walls when it is a tube, the less need be the thickness of the layer of igniter.
All that is required is to have a sufficient amount of igniter to carry current for
a sufficient period to properly heat the incandescer before being burned away
or vaporized or before it ceases to carry current.
In Figure II the incandescer is shown as thickened at the end so as to con-
stitute a terminal part 3.
In Figure III both the incandescer and the igniter are shown as being
thickened to constitute a convenient terminal part.
In Figure IV another form of terminal is shown consisting of a mass 4 of con-
ducting or semi-refractory material cast, moulded or otherwise fitted upon the
ends and constituting terminal parts for the combined incandescer and igniter.
A combined incandescer and igniter (herein termed a couple) with suitable terminal
parts as hereinbefore referred to constitutes a readily replaceable and renewable
device for insertion between the terminals of a lamp. Thus a very simple lamp
may be obtained consisting merely of two leaf springs for example between which
the combined incandescer and igniter or couple is thrust, the terminals of the
combined incandescer and igniter being in contact with the said leaf springs
which act as conductors, the whole being inserted when desired within a globe.
The composition of the incandescer may be varied to suit the requirements of
the case.
Thus, when a very brilliant light is desired the incandescer may be
made of material such as columbin which is somewhat rapidly disintegrated
during incandescence so as to give off a kind of flame. Or, if an incandescer
with prolonged life is desired it can be made of a material which will disintegrate
or change less during incandescence but which may give out less light.
materials for incandescers are well known in connection with gas lighting having
been used, some in connection with the oxy-hydrogen jet and others in con-
nection with what are known as mantles or solid-flame gas burners. It will be
understood that as in the couples shown in Figures I to IV the igniter is de-
structible when heated in air, a new couple requires to be inserted between the
terminals of the lamp at each period of lighting. I shall hereinafter refer to
the said combination as a destructible couple. In such destructible couple it is
of course not necessary that the incandescer should last longer than the maximum
period of lighting, say 16 hours or whatever it may be.
Such
In Figure V, I illustrate another form of couple or combined incandescer and
igniter, this form not being designed as a destructible one but being intended
to be used an indefinite number of times. In this case the incandescer 1 and the
igniter are concentric as in the former figures but the couple differs in this
respect that the incandescer surrounds the igniter and is not intended to be in
contact therewith throughout its luminous length. By luminous length I mean
that part of the incandescer which is between the two ends or terminal parts
and which is relied upon to give out light. In this case it will be seen that the
incandescer 1 consists of a hollow cylinder and that the igniter consists of a
resistance wire, for example of platinum, lying in the geometric axis of the
incandescer and not making contact therewith throughout its luminous length.
This resistance wire is shown as being straight but it may be helical or twisted
if desired. In the precise form shown the ends 5 of the igniter are attached to
clamping beads 6, 7 of conducting material for purposes now to be described.
Figure VI shows the couple or combined incandescer and igniter placed in

page_text: operative position in a lamp or support. In this lamp or support are supporting
brackets 8, 9; 8 being of porcelain, china or other suitable non-conducting
material and not designed to form part of the circuit, whilst 9 is of conducting
material and intended to form part of a circuit. Bracket S is perforated at 10
with a taper opening so as to fit the tapered shoulder 11 of the incandescer when
the couple is passed from left to right into the position shown in Figure VI.
Bracket 9 is perforated at 12 and has a slot 13 therein extending from said per-
foration downwards. This slot is designed to enable the igniter to pass upwards,
at the same time that the couple is being passed from left to right, until it
reaches its position in the centre of the, orifice 12 where it remains out of con-
tact with the bracket 9. 14 is a metallic leaf spring with cup-shaped end 15
designed to receive the bead 7 at the right hand end of the igniter. This cup-
shaped end is also slotted, see Figure VIII, in a manner similar to the bracket 9
and for the same purpose, namely, of admitting the igniter. The leaf spring 14
is pressed towards the bracket 9 when the couple is being placed in position
and when freed from the pressure it pulls with a slight but sufficient force upon
the igniter so as to hold the couple with sufficient firmness in the position shown
in Figure VI. 16 is a thermal contact which may consist of any of the well
known types and in this case is shown as consisting of a thermostatic band
suitably bent or cupped at the end 17 to make good contact with the bead 6.
18 is a conducting terminal, see Figures V and VI, for ensuring good contact
between bracket 9 and the incandescer, but it is not always required.
The action of this form of the invention is as follows:-When the current
is turned on it passes from one terminal of the lamp by spring 14, bead 7,
igniter 2, bead 6, and thermal contact lt to another terminal of the lamp.
Igniter 2 is now raised to a high temperature and its heat is communicated to
the surrounding incandescer 1 until the latter becomes sufficiently conductive to
take part of the current. Instead now of all the current passing by the parts just
mentioned, part of the current will flow from bead 6 through contact 16 as before,
but part will also flow from bead 6 by incandescer 1, terminal socket 18 and
bracket 9. As soon as the incandescer 1 has become sufficiently heated and
sufficiently conductive it will transmit sufficient heat to contact 16 to make the
latter bend outwards towards the position shown in dotted lines. The circuit
between bead 6 and contact band 16 will now be broken and the current will
pass through the lamp by the following parts-from one terminal of the lamp
by spring 14, bead 7, igniter 2, bead 6, incandescer 1, socket terminal 18, and
bracket 9 to another terminal of the lamp. As all the current which now passes
through the lamp traverses the incandescer the latter will continue to give out
light until the current is switched off. It will be seen that the action of the
thermal contact 16 is to place the incandescer and the igniter in series and that
in this form of the invention they remain in series during the lighting period.
In other words, when the current is first turned on the igniter only is in circuit;
but, when the incandescer conducts, contact is broken by the movement of the
contact band 16 away from the bead 6 and the incandescer and igniter are placed
in series. The igniter in this form is one which as is well known decreases in
conductivity with increase of temperature and the incandescer increases in
conductivity with increase of temperature. When therefore they are in series
a steadying effect is obtained and it will be seen that the igniter acts not only
as an igniting resistance for the incandescer but as a steadying resistance for it.
A steadying resistance other than the igniter may however be used when desired.
Instead of the thermostatic band form of cut out or contact. I may employ an
electromagnetic cut out or contact, the electromagnet being placed in circuit
with the incandescer, so that as soon as the incandescer has become sufficiently
conductive the electromagnet shall be energized. Such contact or cut out may
be placed in any convenient position such for example as in the holder or the wall
bracket or the like. I desire it to be understood however that I do not claim

page_text: such contacts or cut outs in themselves, but only when employed so as to place
the igniter and the incandescer in series.
One advantage in having the igniter and the incandescer in series during the
lighting period is that should any accident occur to the incandescer, by breakage
or otherwise, current would not be wasted by passing through the igniter, as
occurs in the known arrangements in which the igniter and incandescer are
arranged in multiple and the igniter cut out of circuit when the incandescer is
giving light. In such case if the incandescer fails the igniter is cut into circuit
and continues to absorb and waste current. Considerable economy is thus secured
by this feature of the invention.
In another type of the invention the temperature of the incandescer is raised
to conducting point by means of an are passing between two parts of the igniter
which latter may be divided for the purpose. Such division may be complete,
in which case however the two parts must, according to this invention, be in
actual contact, or such division may be only partial so as to leave a bridging
part which will serve as an electrical connection. The result is that, in the
case of the completely divided igniter, when the current is switched on an are
will be set up between the contacting parts of the igniter and in the case of the
partially divided igniter the bridging part will be heated and consumed when
an are will be established, the said are in either case heating the incandescer
to the required temperature. This type of the invention is illustrated in Sheet 2
of the drawings, Figures IX and X representing a case of a completely divided
igniter and the other figures on Sheet 2 representing cases of a partially divided
igniter.
Referring now to Figures IX and X, 1 is the incandescer as before and 2 the
igniter, shown in this case as consisting of two separate fine rods 20, 21 of carbon
or carbon mixed with refractory material. When the current is switched on to
this form of couple an arc is set up at the contacting ends of the rods 20, 21
and these consume from said contacting parts, the arc gradually getting longer
until it is broken. By this time however the incandescer has become sufficiently
heated throughout its luminous length to pass the current and it now becomes the
light giving part of the lamp. A small orifice 22 may be provided to permit
a little air and prevent any explosion.
Figure XI is a side elevation, Figure XII a cross section and Figure XIII an
under plan of a form of the invention in which the igniter is partially divided.
Here it will be seen that a bridging piece 23 remains. This bridging piece being
of small cross sectional area for the current which is to pass, is rapidly heated
and consumed, and an arc is set up between the now severed ends which heats
the incandescer 1 as before mentioned.
Figure XIV is a side elevation corresponding with Figure XI but having
terminal parts 4 thereon.
Figure X is a cross section on the linear of Figure XIV.
Figure XVI is a form differing from that shown in Figure XI in the manner
in which the partial division is made. Instead of cutting away throughout
the greater part of the circumference only and so as to expose
part of the
incandescer as in the case in Figure XI, the igniter in Figure XVI, is cut away
throughout the whole circumference without exposing any of the incandescer,
this being done for example by cutting away the igniter in such a manner as
to thin it down as shown. In this case it will be seen that the bridging piece
is of annular form, but its area being reduced in cross section as in the former
case the same result follows. In other words the thin annular part is heated
and consumed and an arc is then set up.
Figure XVII is a cross section on the line y-y of Figure XVI.
To allow for any increased consumption or destruction of the incandescer
by the arc
whilst the arc lasts the incandescer may be thickened at
the part where the arc is established. This is shown in Figures

page_text: XVIII, XIX and XX, of which Figures, XVIII is a side elevation, XIX a
cross section on the line and XX a longitudinal vertical section. In these
figures a divided igniter similar to what is shown in Figures XI, XII and XIII
is employed but the incandescer is thickened at the part 24 for the purpose
specified.
In Figure XX it will be seen that the enlarged or thickened part is longer
than in Figure XVIII it being assumed that in this case a longer are will be
required for the heating up of the incandescer.
In sheet 3 I diagrammatically illustrate two other forms of the invention in
which a completely divided igniter is employed. These forms differ in their
purpose from that shown in Figures IX and X in that whereas the form shown
in Figures IX and X is designed as a desctructible couple, that is to say one which
is intended to be replaced for each lighting period, the forms shown on Sheet 3
are intended for use an indefinite number of times without renewal of any of the
parts.
Figure XXI is a side elevation and Figure XXII a cross section of one form
of that type of the invention just mentioned. In this case, 1 is the incandescer
as before, the igniter consisting of carbon plates 25, 25, the said plates being
held in iron holders 26 forming cores for the solenoid coils 27. Here it will be
seen that the incandescer and the carbon plates constituting the divided igniter
are in multiple. When the current is switched on none will pass through the
incandescer but the whole will pass through the carbons and coils 27, 27 which
will attract the cores 26 and strike the arc in the well known manner of an arc
lamp. This are will travel along the meeting line of the plates, or in other
words above the top of the incandescer from end to end, and heat the same, when
current will flow through the incandescer and cause it to give out light. To
prevent any chance of the carbon plates coming down upon the incandescer so as
to injure it any convenient stopping device may be employed. For example,
the plates 25, might be made of greater width than the incandescer and at the
ends where the plates meet stout stoneware stops be placed so as to prevent the
said plates feeding below the level shown in Figure XXII. Any convenient
known method may be employed for re-starting the arc should re-ignition from
any cause be required. One convenient way of doing this is by means of Pearce's
method but a thermo-electric band may also be employed for the purpose. For
the purpose of more readily heating the incandescer by means of the are I may
employ the well known Jamin method of deflecting the arc towards or upon the
incandescer after the manner employed for example by de Benardos, Rogerson
& Statter, and others. When desired a clutch mechanism may be employed in
the form of lamp shown in Figures XXI and XXII acting after the well known
manner hereinafter referred to in the case of the lamp shown in Figures XXIII
and XXIV.
Figures XXIII and XXIV illustrate another form of this type of lamp. In
this case however the igniter is enclosed within the incandescer. The said igniter
consists of the lower carbon 28 and the upper carbon 29 which latter is within
the iron carbon holder 31 which acts as a core to the solenoid 32. The carbons
28 and 29, which together constitute the divided igniter, are shown together in
Figure XXIII and separated in Figure XXIV owing in the later case to the
are having been struck through the action of the clutch 30 in the well known
manner of clutch are lamps. Here it will be seen that the igniter and incandescer
are again arranged in parallel or multiple. is the stop against which the
clutch is brought in the well known manner so as to allow for the feed of the
upper carbon. In these figures the devices for striking the arc and of feeding
the carbons are well known and per se do not form any part of this invention.
So far as the action of the igniter upon the incandescer is concerned it will be
seen that the incandescer is heated by the are formed between the two parts of
the divided igniter. In the normal position the carbons are in contact but as
soon as the current is switched on the are is struck in the well known manner

page_text: of a clutch lamp and the incandescer is heated by the said arc. When the incan-
descer becomes conductive and gives out light current flows through it and the
are continues until the carbons burn away sufficiently to break the arc,
The
current now cease to flow through the igniter but the incandescer being in
parallel therewith takes the current and this current passing through the sole-
noid 32 maintains the carbons in the separated position as long as the incandescer
is giving out light. When the current is switched off then the solenoid no longer
attracts the core upwards, the clutch is released and the carbons constituting the
divided igniter are brought together again, so that when current is again
switched on the same cycle of operations will be gone through, and the light
again produced. In this form of lamp there is of course no necessity to replace
the igniter or the incandescer at each period of lighting and naturally an in-
candescer is chosen which has the longest possible life. By enclosing the arc
or the working parts or certain of them after the manner well known in con-
vection with enclosed arc lamps the wasting away of the igniter may be retarded.
In the case of some forms of non-destructible couples when it is desired to
use an igniter of a kind destructible in the open air, such for example as carbon,
iron or other wire, it may be enclosed in a bulb as in ordinary incandescent
electric lamps. A convenient form for the purpose is an incandescent carbon
lamp of the kind manufactured and sold by the Edison & Swan Company for
chain" lighting, that is to say lighting in which the said lamps have tubular
bulbs with one terminal at each end of the tube and are placed end to end some-
what after the manner of the links of a chain. This form is applicable in the
case of incandescers which do not require to be raised to what is comparatively
a very high temperature.
It is obvious that the thermostatic band may be employed not only to act
as above mentioned but also to separate or to bring together, according to the
effect desired, the carbons or other electrodes between which the arc is formed.
Thus the said band may be set to separate the carbons after it has been raised to
a temperature which is only reached when the conductivity of the incandescer
And
is assured.
or,
it may be set to bring the said carbons together when the
rupture (or sufficient decrease) of the current through the incandescer has caused
cooling down.
I desire it to be understood that in so far as arc ignition is concerned I lay
no claim to the use of a fusible incandescer.
I desire it to be understood that I lay no claim to the mere use of an electric
are for the purpose of heating an incandescer as I am aware that that has been
suggested previously, but in such suggestion the device was inoperative. I
therefore do not claim are ignition with a completely divided igniter unless the
two parts of the igniter are primarily in contact so that current may flow through
the igniter, or unless the igniter is employed in conjunction with means for
moving the said divided parts so that an are may be struck and or regulated
when desired.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is
1. A destructible couple consisting of an incandescer with a conducting or
semi-refractory coating constituting an igniter, substantially as set forth.
2. A destructible couple consisting of the combination of an incandescer and
an igniter of carbon in the form of a coating on the surface of the said incandescer.
3. A destructible couple consisting of the combination of an incandescer with
an igniter of metal deposited as a coating on the surface of the incandescer.
4. A destructible couple with terminal parts substantially as set forth.
5. The combination of an igniter and a tubular incandescer surrounding the
said igniter and out of contact therewith throughout its luminous length.

page_text: 6. The combination of an incandescer and a divided igniter (the two parts of
which are in contact in the first instance) substantially as set forth.
7. The combination of an incandescer and a partially divided igniter sub-
stantially as set forth.
8. A partially divided igniter of the type set forth with reference to Figures XI,
XIII, XIV, XVIII and XX.
9. A partially divided igniter of the type set forth with reference to Figure XVI
10. The combination of an incandescer and a divided igniter, the said igniter
being out of contact with the incandescer throughout the luminous length thereof.
11. The combination of an incandescer, a divided igniter, and means for
separating the parts of the divided igniter from one another so as to strike an
arc between them.
12. The combination of an incandescer, a divided igniter, means for separating
the parts of the said divided igniter from one another so as to strike an arc
between them and means for bringing the said parts together again should the
current fail to flow through the incandescer.
13. The combination of an incandescer, a divided igniter, and means for
separating the parts of the said divided igniter, regulating their distance from
one another and bringing them together when required.
14. The combination of a hollow or tubular incandescer and a divided igniter,
the said divided igniter lying within the incandescer and being out of contact
therewith throughout the luminous length thereof.
15. The combination of a hollow or tubular incandescer, a divided igniter
within the said incandescer, and means for separating the parts of the divided
igniter from one another so as to strike an arc between them.
16. The combination of a hollow or tubular incandescer, a divided igniter
within said incandescer, means for separating the parts of the said divided igniter
from one another so as to strike an are between them, and means for bringing
the said parts together again should the current fail to flow through the
incandescer.
17. Placing the igniter and incandescer in series after the latter has been
rendered conductive substantially as and for the purpose set forth.
18. The combination of an incandescer, an igniter and means for placing the
two in series when the incandescer has become sufficiently conductive.
19. In a lamp in which a divided igniter is employed, having the said divided
igniter and the incandescer in multiple or parallel.
20. Arranging an igniter and an incandescer in such manner that the former
acts not only as a heating but as a steadying resistance.
Dated this 20th day of December 1899.
J. G. LORRAIN,
Communicatee.