IMPROVEMENTS IN THE MEANS OR APPARATUS FOR OBTAINING LIGHT BY ELECTRICITY, AND DISTRIBUTING, REGULATING, AND MEASURING THE ELECTRIC CURRENTS FOR THE SAME
Year: 1878

page_text: LETTERS PATENT to St. George Lane Fox, of Telegraph Street, in the City of
London, for the Invention of "IMPROVEMENTS IN THE MEANS OR APPARATUS
FOR OBTAINING LIGHT BY ELECTRICITY, AND DISTRIBUTING, REGULATING, AND
MEASURING THE ELECTRIC CURRENTS FOR THE SAME."
Sealed the 24th January 1879, and dated the 14th November 1878.
PROVISIONAL SPECIFICATION left by the said St. George Lanc Fox at the
Office of the Commissioners of Patents on the 14th November 1878.
ST. GEORGE LANE FOX, of Telegraph Street, in the City of London. "IMPROVE-
MENTS IN THE MEANS OR APPARATUS FOR OBTAINING LIGHT BY ELECTRICITY, AND
DISTRIBUTING, REGULATING, AND MEASURING THE ELECTRIC CURRENTS FOR THE
SAME."
My Invention has reference to the application of electricity to lighting purposes.
In order to obtain light from an electric current make use of a sheet of
platinized or iridized or carbonized asbestos or other suitable material supported
between two conducting terminals of platinum or other suitable material; and in
order to preserve the incandescent substance in a good condition and to prevent its
deterioration I enclose the whole in a glass or other suitable transparent vessel or
cover through which the platinum supports are fused. This vessel or cover is then
exhausted of air by means of a small tube leading from it, and it may then, if
thought desirable, be filled with some gas or vapor which has no action on the
material used for producing the light.
When platinum, iridium, iron, or other metal is used either pure or alloyed, with
some other material or materials, and either plain or covered with some suitable
material, such as powdered asbestos, magnesia, or a vitreous substance, I prefer to
coil a long strip or wire into the form of a spiral, and to attach the two ends to

page_text: platinum wires fixed side by side by fusing into a piece of glass or otherwise so
that they run parallel to one another, one wire carrying the top of the spiral and
the other the lower end. The length and thickness of the spiral will depend on
the intensity of the light required and the electro-motive force available. The
ends of the spiral should be united to these wires with some hard solder. This
spiral is then enclosed in a globular or flask shaped glass vessel whose neck is
sufficiently large to admit it; and the neck should then be closed up around the
two supporting wires so as to seal them in and make the whole vessel air tight. A
small tube projecting from some part of the neck is then connected with a Sprengel
air pump or other exhausting apparatus, and the air is then removed as completely
as possible and the tube sealed up, some gas being previously admitted, if desired,
into the vessel, as before described. The neck of the vessel may be fixed to some
suitable holder or support, and the projecting platinum wires should be connected
to proper terminals.
According to another method or arrangement for obtaining light by the incan-
descence of carbon or other suitable material the said material is enclosed, as before
described, in a glass vessel from which the air is exhausted or which is filled with
any suitable gas, and the terminals are, as before described, fused into the glass at
the lower end of the neck where it is sealed up; or the glass vessel may be made
in any way by which it can be readily opened when desired, and be again hermeti-
cally scaled; one of the terminals leads by a proper conductor to a small piece of
hard coko, graphite, or other suitable material, and is fixed thereto so as to be in
good electrical contact with it; this piece of carbon or material may be spherical or
of other desired shape. The other terminal leads to the bottom of a long cylindrical
vessel containing mercury; in the mercury is a float of some conducting material
capable of vertical movement and attached to a metallic wire or rod passing through
and fitting into an aperture or guide at the top of the cylindrical vessel; to
this wire or guide is fixed a long pencil of carbon, about th of an inch thick,
This carbon being fixed to the rod of the float is pressed upwards by the buoyant
action of the mercury, and the upper end of the pencil is thus pressed lightly
against the lower surface of the piece of coke or other carbon or material above
mentioned, so that by passing an electric current through the two terminals a
brilliant light is emitted at the point of contact of the two carbons or materials.
If the pencil wears away it is by virtue of the float and guide retained in the
proper position, and presses with an equal pressure against the carbon or material
above.
In laying on electricity to a building, district, or town for lighting purposes I
arrange the conductors for the conveyance of the electricity in a manner somewhat
similar to that adopted for the supply of gas, so that from the point or station
where the electric currents are developed I lead a main conductor or a number of
main conductors whose size should be as large as practicable in order to prevent
great inequality of tension or electro-motive force in different parts. From these
main conductors branch off at different points sub-mains whose size should depend
on the amount of electricity to be conveyed. One of the poles or electrodes of the
electric generator or generators, and of the reservoir batteries (herein-after referred
to), should be connected with the mains or branches and the opposite poles to the
earth by means of gas or water pipes or otherwise. In order to prevent a great
inequality in the tension or electro-motive force in different parts of the area
supplied in case the main conductors are not sufficiently large, I insert at the point
of junction between each branch and the main conductor a regulator, hereinafter
described, whose object is to increase the resistance at the point of junction as the
electro-motive force in the branch conductors rises, and so to prevent too large a
current passing through those branches joining the main at points where the
electro motive force is temporarily high, and to decrease the resistance when the
electro motivo force falls, and so to allow a constant flow in that direction. By
this means although the electro-motive force in the main conductors will necessarily

page_text: be continually altering owing to the alteration of draft in different directions the
electro-motive force in the branches themselves will be maintained vory nearly
constant. Smaller regulators may be used at the points where sub branchos are led
off from the main branches, and so on for the smaller branches. By this means it
will be seen that by connecting the various sub branches or smaller branches at any
required points with lamps an amount of electricity will pass through them
according to the resistance they present to its passage.
Tho further control and regulation of the electro motive force can be conveniently
effected by placing in conjunction with the numerous branches or different parts of
the main an arrangement of secondary batteries, for which purpose I prefer to uso
those made with lead and sulphuric acid. In these batteries large quantities of
electricity may be stored up during the time when the demand is small so as to be
available for use when the demand is great. The regulator herein before referred to
consists of a magneto electric arrangement in which a coil of wiro is placed in
circuit between the branch conductor and the earth, so that more or less electricity
will flow through it according as the electro motive force in the conductor is great
or small. A soft iron core in the centre of this coil will consequently be magnetized
in a degree proportionate to and varying with the clectro motive force of the
conductor at the point where the wire of the coil is connected. A spring armature
working an arrangement of levers approaches or recedes from the core as the
strength of its magnetism varies, so that a pointed, tapered, or conical shaped body
fixed to the end of a lever is immersed point downwards to a greater or less degree
in some conducting fluid, preferably mercury, and so will alter the amount of
resistance between the said pointed body and the conducting fluid; if therefore the
branch through which the flow of electricity is to be regulated is connected to this
mercury and the pointed body with the main, or vice versa, the resistance interposed
between the main and the branch conductor will be increased when the electro
motive force in the branch conductor rises and diminished when it falls. The
electrometer arrangement described in a Provisional Specification lodged by me on
the 9th October 1878, No. 3988, combined with a pointed body and conducting
fluid, may be substituted for the electro magnetic arrangement just described. A
similar electro-magnetic arrangement may be substituted for the said electrometer
apparatus, as described in my said Provisional Specification, for the purpose of
regulating the supply of electricity according to the electro motive force, or for
moving the commutator of the secondary batteries as the height of the tension
requires. In the present improved arrangement the spring armature works by an
arrangement of levers, an indicator moving along a scale, its position depending
upon the attractive force of the electro magnet, and consequently if it be connected
with the main at any point it will indicate the amount of electro motive force at
that point. A sliding piece with contact pegs will allow the working of levers in
connection with the commutators of the secondary batteries, or with the steam
valves of the engine, which works the electric generators, as described in my said
Provisional Specification.
For the purpose of measuring the electric current which passes through any given
conductor I use an apparatus which consists chiefly of an electro magnet, the coil of
which forms part of the circuit of the conductor, the amount of electricity passing
through which it is desired to ascertain. In conjunction with this electro magnet
is an armature attached to a spring in connection with a cone or wedge shaped
body working in a suitably shaped orifice. This orifice leads by means of a pipe to
an ordinary gas meter, and thence to a reservoir or air chamber kept constantly at
a certain pressure, either above or below that of the atmosphere, by means of a
water air pump, a small electric pump, or other suitable means. This chamber is
provided with a valve which opens when the pressure increases or decreases from a
certain point. In this manner the meter has on one side a constant pressure, and
on the other an inlet or outlet whose extent will depend on the position of the cone
shaped body, and consequently on the distance of the armature from the magnet;

page_text: when no current is passing this valve will be completely closed; a current of a
greater or less strength will cause an opening of corresponding extent, and therefore
a corresponding flow of air through the meter.
Instead of a meter and air chamber arranged as before described, I sometimes
employ a gas holder, so that there is a constant pressure. within it. The height of
the gas holder, determined by a scale at its side, will represent the amount of
electricity passed.
The whole apparatus may be worked either by pressure or vacuum, and the gas
meter registering the amount of air passing through it should bear a constant ratio
to the amount of electricity passing round the coils of the electro magnet.
The adjustment of this apparatus can be conveniently effected by varying the
shape of the cone or wedge shaped body, or by altering the tension of the armature
spring.
It may sometimes be advisable to use a shunted portion of the circuit to work
this meter, so that the whole current need not pass through the coil of the electro
magnet, but a portion which bears a fixed ratio to the whole.
Although I prefer to use a gas meter so as to measure the volume of air passed
through the valve, water may, if desired, be used instead of air, and the amount of
water passed through the valve be made to represent the consumption of electricity
in the same way as in the other case it is represented by the passage of a given
quantity of air.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said St. George Lane Fox in the Great Seal Patent Office on the 14th
May 1879.
ST. GEORGE LANE Fox, of Telegraph Street, in the City of London. "IMPROVE-
MENTS IN THE MEANS OR APPARATUS FOR OBTAINING LIGHT BY ELECTRICITY, AND
DISTRIBUTING, Regulating, anD MEASURING THE ELECTRIC CURRENTS FOR THE
SAME."
My Invention has reference to the application of electricity to lighting purposes.
In order to obtain light by electricity I cause a current to pass through a resisting
medium composed of some refractory material so as to render it incandescent. For
this purpose I sometimes make use of some difficultly fusible metallic body such as
platinum-iridium alloy in the form of a strip of wire. I prefor however to use the com-
pound material mentioned in the Specification of my Patent, dated October 12th, 1878,
No. 4043, and which as therein described is composed of asbestos or other suitable.
non-conducting refractory material such as lime, magnesia, or steatite, impregnated
with or covering the surface of some refractory conducting material such as carbon,
platinum, or iridium. In order to prevent the deterioration of the material it is some-
times necessary to enclose it in a glass cover filled with some gas or vapor which
has no action on the incandescent material.
I
In laying on electricity to a building, district, or town for lighting purposes
arrange the conductors for the conveyance of the electricity as described in the
Specification of my Patent dated October 9th, 1878, No. 3988, that is to say, in a
manner somewhat similar to that adopted for the supply of gas, so that from the
point or station where the electric currents are developed I lead a main conductor
or a number of main conductors whose size should be as large as practicable, in
order to prevent great inequality of tension or electro motive force in different parts.
From these main conductors branch off at different points sub-mains, whose size
should depend on the amount of electricity to be conveyed. One of the poles or
electrodes of the electric generator or generators and of the reservoir or secondary
batteries (described in the Specification of my said Patent of 9th October 1878),
should be connected with the mains or branches and the opposite poles to the earth
by means of gas or water pipes or otherwise. In order to prevent a great inequality
in the tension or electro motive force in different parts of the area supplied, in case
the main conductors are not sufficiently large I insert at the point of junction
between each branch and the main conductor (or between any two parts of the
main) a regulator hereinafter described, whose object is to increase the resistance
at the point of junction, as the electro motive force in the branch conductors rises,
and so to prevent too large a current passing through those branches joining the
main at points where the electro motive force is temporarily high, and to decrease
the resistance when the electro motive force falls, and so to equalize the electro
motive force in that direction. By this means although the electro motive force in
the main conductors may be continually altering, owing to the alteration of draft in
different directions, the electro motive force in the branches themselves will be
maintained very nearly constant.
Smaller regulators may be used at the points where sub-branches are led off from
the main branches and so on for the smaller branches. By this means it will be
seen that by connecting the various sub-branches or smaller branches at any required
points with lamps a constant amount of electricity will pass through them according
to the resistance they present to its passage.
The regulator herein before referred to should be such as that represented in Figure.
1. It consists of a magneto electric arrangement in which a coil of wire a is placed

page_text: in circuit between the branch conductor band the earth so that more or less
electricity will flow through it, according as the electro motive force in the conductor
is great or small. A soft iron core in the centre of this coil a will consequently be
magnetised in a degree proportionate to and varying with the electro motive force
of the conductor at the point where the wire of the coil is connected. An armature
c, fitted with a weight d, or a spring, approaches or recedes from the core as the
strength of its magnetism varies so that a rheostat in connection with the armature
may be made to interpose more or less resistance to the passage of the current into
that part of the branch (or main) where it is dosired to preserve a constant electro
motive force. The rheostat is composed of a vessel e, containing a conducting fluid,
preferably mercury, and is fixed either as shown directly to the end of the armature
or with a suitable arrangement of levers between them; f is a resistance coil; the
plates g of which dip into the mercury vessel e. It will be seen that as the mercury
rises or falls with armature c as the electro motive force varies, there will be more
or less layers of the resistance coil in circuit, thus the resistance interposed between
the main and the branch conductor will be increased when the electro motive
force in the branch conductor rises, and diminished when it falls. The weight dis
carried by a bell.crank centred at d¹, whose shorter arm may be made adjustable in
any suitable manner.
A somewhat similar electro magnetic arrangement miny be substituted for the.
electro-meter described in the Specification of iny said Patent of 9th October 1878,.
for the purpose of regulating the supply of electricity, according to the electro motive
force or for moving the commutator of the secondary batteries as the height of the
tension requires. In the present arrangement, which is represented in Figure 2, the
weighted or spring armature c works an indicator h moving along a scale i, its posi-
tion depending upon the attractive force of the electro magnet a, and consequently
if it be connected with the main at any point it will indicate the amount of electro
motive force at that point. A sliding piece k, with platinum or other suitable con-
tact pegs 1, 1, will allow or control the working through the intermediation of
electro magnets m, m, of levers in connection with the commutators of the
secondary batteries or with the steam valve of the engine which works the electric
generators.
For the purpose of measuring the electric current which passes through any given
conductor I use an apparatus which consists chiefly of an electro-magnet, the coil
of which forms part of the circuit of the conductor the amount of electricity passing
through which it is desired to ascertain. In conjunction with this electro inagnet
is an armature attached to a weight or spring in connection with a cone or wedge
shaped body working in a suitably shaped orifice. This orifice leads by means of
a pipe to an ordinary gas meter, and thence to a reservoir or air chamber kept con-
stantly at a certain pressure either above or below that of the atmosphere by means
of a water air pump, a small electric pump, or other suitable means. In this manner
the meter has on one side a constant pressure and on the other an inlet or outlet
whose extent will depend on the position of the cone shaped body, and consequently
on the distance of the armature from the magnet. When no current is passing this
valve will be completely closed. A current of a greater or less strength will cause
an opening of corresponding extent, and therefore a corresponding flow of air
through the meter.
Instead of a meter and air chamber arranged as before described I sometimes
employ a gas holder having a constant pressure within it. The height of the gas
holder, determined by a scale at its side, will represent the amount of electricity
passed.
The whole apparatus may be worked either by pressure or vacuum, and the
amount of air registered as passing through the meter should bear a constant ratio
to the amount of electricity passing round the coils of the electro magnet.
The adjustment of this apparatus can be conveniently effected by varying the

page_text: shape of the cone or wedge shaped body, or by altering the weight attached to the
armature or the tension of its spring.
It may sometimes be advisable to use a shunted portion of the circuit to work
this meter so that the whole current need not pass through the coil of the electro
magnet, but a portion which bears a fixed ratio to the whole.
Although I prefer to use a gas meter so as to measure the volume of air passed
through the valve, water may if desired be used instead of air, and the amount of
water passed through the valve be made to represent the consumption of electricity
in the same way as in the other case it is represented by the passage of a given
quantity of air.
Figure 3 represents an apparatus constructed according to my Invention for
measuring the electric current which passes through any given conductor. a is an
electro inagnet, the coil of which forms part of the circuit of the conductor; b, the
amount of electricity passing through which for the supply of say a house at X it
is desired to ascertain. C is an armature attached to a spring d; instead of this
spring however I prefer to employ a weight, as in the modification shown in
Figures 4 and 5, and herein-after described, as I consider a weight more reliable.
This armature carries a cone or wedge shaped body e working in an orifice f. This
orifice leads by a pipe g to a meter like an ordinary gas meter, and thence by a
pipe i to an air chamber k. The air in this chamber is kept constantly at a certain
pressure, and this may be conveniently effected by means of a water air pump, as
shown, that is to say, water from a reservoir in descending by the pipe m draws
in air by the inlet n and carries it with it into the chamber k; o is the water outlet
pipe; p is a valve to the chamber k, which valve opens when the pressure increases
beyond a certain point. Thus the meter h has on one side a constant pressure and
on the other side an outlet at f whose extent depends upon the position of the
cone e, and therefore upon the distance of the armature c from the magnet a. As
has been before explained, when no current is passing the cone e closes the orifice f,
and when a current of a greater or less strength is passing the orifice f is opened
to a corresponding extent, and consequently air to a like corresponding extent flows
through the meter h. Figure 3, which I have just described, is only a diagram of
the apparatus; its construction will be fully understood on reference to Figures 4
and 5, which represent in front and side elevations respectively (Figure 5 being
partly in section) a modified arrangement of the apparatus in which the air chamber
is kept charged by means of an electric air pump, and in which a governor is inter-
posed between the meter and the outlet valve or orifice. In Figures 4 and 5 a is
the electro magnet whose coil forms part of the conductor b, the amount of electricity
passed through which it is desired to ascertain. c is the armature fitted with a
weight d. This weight is carried on one arm of a bell crank d¹, d', centred at d²,
and the other arm of the bell crank is connected by a link d³ to the armature.
e is the cone or valve, which may either be attached to the armature or simply rest
thereon. is the orifice in which the valve or cone e works. This orifice leads by
a pipe g to a governor p, which I prefer to be what is known as a double dry gas
governor, thence by a pipe q to the meter h, and from the meter by a pipe i to an
air chamber. This air chamber is kept charged by means of an electric air pump, and
this is effected as follows:- is an electro magnet, and 8 its armature, which is
carried by a levert centred at u. When the armature s is attracted by the magnet
the outer end of the lever t presses upon and pushes down a rod v which is attached
to a plunger in a mercury vessel w, the result of which movement is that the
mercury forced up in a vessel which is in communication with the vessel w.
This vessel x is closed except to an air inlet pipe y, and to an air outlet pipes which
communicates with the air chamber k. The rising of the mercury in the vessel x
as above stated drives a corresponding volume of air up the pipe to the air chainber,
and the return of air from the chamber is prevented by a suitable valve fitted in the
pipe 3. When the armature s ceases to be attracted by the magnet the mercury
which has been previously forced from the vessel w to the vessel x returns, air

page_text: entering the vessel by the pipe y which has a valve opening inwards, and the
plunger in the vessel w therefore rises and lifts the armatures until it is again
attracted by its magnet; a pumping action is thus kept up. Instead of having
mercury in the vessel wand a plunger to act upon it, the vessel w may simply
contain air, and the rod v be made to act upon a flexible diaphragm in the vessel so
as to compress the air below such diaphragm, and the rod v is in this case lifted by
a suitable spring. The air chamber a contains a given quantity of paraffin oil or
other suitable liquid into which a pipe / from an upper chamber ³ dips, so that as
the air is more or less compressed in the chamber k, the liquid is more or less forced
up the pipe into the chamber which has an aperture at the top for the admission
and exit of air as necessary. In order to break the contact when the pressure in
the chamber reaches a certain point I fit to this chamber a syphon ³ made of
metal, but with a glass piece interposed. The bend of the syphon contains
mercury at such a level that it makes contact between the two metal portions of the
syphon except when the pressure is sufficient to force its level down into the glass
portion; the contact is then broken. The manner in which contact is alternately
made and broken so as to enable the magnet to alternately attract and free its
armature 8, and thus effect the pumping action before explained is as follows:-From
the tail of the levert is suspended by a rod t a plate or piece of lead to which dips
in sulphuric acid or other liquid in a trough t³. The contact of the lead t with the
liquid in the trough 3 completes the electric circuit in which are the coils of the
magnet so that the armature is attracted. As the armature descends the lead t
is gradually lifted out of the liquid, and as soon as it is quite out of contact there-
with the circuit is broken.
Although I prefer that the measuring of the clectric current should be effected by
causing the movement or position of the armature c of the electro magnet a to
control the flow of air through a meter in the manner herein before explained, the
same result can be obtained by causing the movement or position of the said armature
c to control a meter by mechanical means. This may be effected in the manner
shown in Figure 6. a is the electro magnet, as in Figures 3, 4, and 5; b the con-
ductor; c, the armature with its weight d. The lever which carries the armature c
bears at its outer end upon a spindle A which is free to move vertically in a guide
B, and forms a pivot for a spindle A¹ which is supported by a spring C to keep the
spindle A in contact with the armature lever. On the spindle A' is a disc D which
is in frictional contact with another disc E, this disc E is driven by clockwork at F,
and is kept against the disc D by a spring. On the spindle A¹ is also a long pinion
G in gear with a wheel H, and this wheel actuates the train of wheels which
constitute the meter. or counting apparatus. When no current is passing through
the conductor b and the armature therefore is not attracted by the magnet a, and
is consequently in its highest position the disc D is exactly in the centre of the
disc E, and is therefore not driven thereby ; but as when a current is passing through
the conductor b the armature c is more or less attracted by the magnet a, the
spindle A with the disc D is more or less forced down, and the disc D being thus
pushed more or less from the centre of the disc E is driven at a proportionate speed
and a corresponding motion is given to the wheel H and to the méter; the extent
to which the meter is acted upon will thus depend upon the time the current is
passing through the conductor b and to the amount of current passed during such
time.
"
And having now described the nature of my said Invention, and in what manner
the same is to be performed, I declare that I claim as my "Improvements in the
Means or Apparatus for Obtaining Light by Electricity, and Distributing, Regula-
ting, and Measuring the Electric Currents for the same,'
First. Constructing apparatus substantially as herein before described, and repre-
sented in Figure 1 of the annexed Drawings, for regulating the distribution of the
electric currents.

page_text: Second. The improved electrometer or apparatus hereinbefore described, and
represented in Figure 2, arranged and acting as and for the purposes explained.
Third. The construction of apparatus for measuring the electric currents passing
through a conductor when such apparatus comprises an electro magnet whose coil
forms part of the circuit of the conductor or a shunted portion of the circuit, and
when the movement or position of the armature of such electro magnet controls the
working of a meter or counting apparatus, substantially in the manner herein before
explained.
Lastly. I claim specially the measuring apparatus constructed and acting sub-
stantially as hereinbefore described with reference respectively to Figure 3, and
Figures 4 and 5 of the annexed Drawings.
In witness whereof, I, the said St. George Lane Fox, have hereunto set my
hand and seal, this Fourteenth day of May, One thousand eight hundred
and seventy nine.
ST. G. LANE FOX. (L.S.)