IMPROVEMENTS IN THE APPLICATION OF ELECTRICITY TO LIGHTING AND HEATING PURPOSES, AND IN THE MEANS OR APPARATUS EMPLOYED THEREIN.
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 APPLICATION OF
ELECTRICITY TO LIGHTING AND HEATING PURPOSES, AND IN THE MEANS OR
APPARATUS EMPLOYED THEREIN.'
"
PROVISIONAL SPECIFICATION left by the said St. George Lane Fox at the
Office of the Commissioners of Patents on the 12th October 1878.
ST. GEORGE LANE Fox, of Telegraph Street, in the City of London. "IMPROVE-
MENTS IN THE APPLICATION OF ELECTRICITY TO LIGHTING AND HEATING PURPOSES,
AND IN THE MEANS OR APPARATUS EMPLOYED THEREIN."
In a Provisional Specification lodged by me on the 9th day of October 1878,
(No. 3988), I stated that a chief object to be attained in lighting by electricity
is to prevent as much as possible the dissipation of force in the form of heat,
and to concentrato and intensify it in the forin of light, and I described the use of
spiral strips of metal foil or wire having a tube of talc, glass, fire-clay, steatite, or
lime within the spiral, and one of talc or glass outside, the two conductors being
respectively connected with the two ends of the strips. In order to increase the
retention of heat I now according to my present improvements cover the surface of
the strips with some good non-heat conducting material, and I use for this purpose
finely divided asbestos, fire-clay, lime, or steatite, or even some vitreous material
or a mixture of the vitreous material with one or more of the other materials,
the vitreous material in the latter case serving to hold the powdered asbestos or
other material on the foil. The radiation of heat from the surface would thus
to a great extent be prevented; I sometimes employ asbestos itself platinized or
saturated with some conducting material. The asbestos may be woven or made
up in the form of paper.
In order to apply electricity to heating purposes, a coil of fine wire may be
used which will be heated in a greater or less degree when the electric current

page_text: passes through it. The intensity of the heat is determined by the length and
thickness of the wire or foil. Platinum is well suited to the purpose, but iron
will answer.
For heating water the wire or foil is wound or otherwise arranged
at the bottom of the receptacle in which the water is contained, such receptacle
being made of earthenware or other suitable material; the water becomes heated
by contact with the wire or foil. For atmospheric heating the wire may either be
used plain and bare, or in conjuntion with asbestos, fire-clay, lime, or steatite.
Where very high temperatures are required, such as for melting metals for example,
I construct a furnace of the best non-heat conducting material available, and I
shape it internally to correspond with the form of the crucible to be licated.
I coil or apply the heating wires or strips round inner surface of the furnace,
and pass them out through the sides or bottom. The wire or strip employed as
the medium for the development of heat should be much thicker at the ends
in order to prevent excessive heating at the point of exit from the furnace,
where it should go direct to some large body of conducting material to which it
must be properly secured by some metallic connection. When the crucible is
inserted the whole must be covered so that the heat will be retained.
In order to regulate the electric current so as to increase or diminish the supply
of heat or light, I join up in circuit an instrument composed of a hollow cylinder
of glass or other suitable material fixed to a metallic base; the cylinder is partly
filled with mercury or other suitable liquid in which dips an adjustable rod mado
by preference of copper or silver; this rod is pointed and is in metallic contact
with a terminal.
If a current pass from this terminal to the metal base (which is in metallic
contact with the other terminal), its flow can be regulated by adjusting the
height of the rod so as to increase or diminish the resistance; if the rod be
lowered the resistance is diminished; if it be raised the resistance is increased.
The ends of the conductors used for heating or lighting should have less resistance
than any other part, so as to prevent overheating at the point of junction with
the terminals, and this is effected by making them thicker towards the ends, the
ends being led directly to a large mass of some good conducting material.
When a number of Plantés (lead and sulphuric acid) cells or batterics joined
together in "series" are employed as reservoirs for the electricity, as described in
my former Provisional Specification, they should have a very large surface, and
there should be several of them connected up at various points of the mains, so that
by increasing the electro-motive force during the hours when not much electricity
is being used they will become charged, and the electric force will be stored up in
them so tint _icient supply will be available when the electro-motive force
falls, owing to the draft from the mains when the force is most used and needed.
Or I sometimes supply each of these reservoir batteries with commutators and with
the means of working them, so that it will not be necessary to increase the electro-
motive force in the mains in order to charge them, but by merely coupling two or
more parts or the whole battery for "quantity," they can be charged with a low
electro-motive force, and be capable of giving by an alteration of the commutators
the full tension when required.

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 12th
April 1879.
ST. GEORGE LANE Fox, of Telegraph Street, in the City of London. " IMPROVE-
MENTS IN THE APPLICATION OF ELECTRICITY TO LIGHTING AND HEATING PURPOSES,
AND IN THE MEANS OR APPARATUS EMPLOYED THEREIN."
In the Specification of former Letters Patent granted to me and dated the 9th
day of October 1878, No. 3988, I described that light might be produced by
passing an electric current through a thin strip or wire of some suitable material, an
alloy of platinum and iridium being preferred. According to the present Invention
I cover the surface of the strips or wires with some suitable refractory material,
and I use for this purpose finely divided asbestos, fire-clay, lime, magnesia, or
steatite, or even some vitreous inaterial, or a mixture of the vitreous material with
one or more of the other materials; the vitreous material in the latter case serving
to hold the powdered asbestos or other material on the foil. The object of covering
the wires or strips of inetal with some earthy material, such as lime, magnesia,
steatite, &c., is that at a given temperature they seem to radiate or give off more
luminous rays in proportion to the dark or non-luminous rays than does the
bright metallic surface of the platinum iridium wire at the same temperature,
and consequently the production of light is in this manner to a certain extent
economized. I sometimes employ asbestos or other suitable non-conducting
refractory material saturated or impregnated with some conducting refractory
material, such for example as carbon or iridium. The asbestos may be woven or
made up in the form of paper.
Figures 1 and 2 of the annexed Drawings represent an electric lamp in which
the luminous surface which I will term the "bridge" is made of asbestos or similar
non-conducting material, saturated or impregnated with some refractory conducting
material, such as carbon or iridium; A is the bridge held by metallic clips B, B,
which are attached to the conductors C, C. These conductors pass through the
top D of the flask E which is hermetically sealed and is filled with nitrogen gas.
The luminous portion a to a¹ of the bridge is of higher resistance than the rest.
In order to apply electricity to heating purposes a coil of fine wire may be used,
which will be heated in a greater or less degree when the electric current passes
through it. The intensity of the heat is determined by the length and thickness of
the wire or foil. Platinum is well suited to the purpose but iron will answer.
Or I use a larger conductor of some bad conducting refractory material, such as
carbon (preferably in the form of graphite), which in conjunction with fire-clay or
similar material may be made to form an inner lining of the furnace.
For heating water the wire or foil is wound or otherwise arranged at the bottom
of the receptacle in which the water is contained, such receptacle being made of
earthenware or other suitable material, the water becomes heated by the wire or
foil. The wire or foil should of course be enameled or otherwise insulated, or it
may be kept apart from the water or substance to be heated by a suitable
diaphragm, and immersed and surrounded by some insulating fluid, such as oil.
For baking, heating rooms, and other atmospheric heating the wire may either
be used plain and bare or in conjunction with asbestos, fire-clay, lime, or steatite.
Where very high temperatures are required, such as for melting metals for example,
I construct a furnace of the best non-heat conducting material available, and I shape
t internally to correspond with the form of the crucible to be heated. I coil or
apply the heating conductors round the inner surface of the furnace, and pass them
ut through the sides or bottom.
Figures 3 and 4 are respectively a vertical section and a plan with the cover
emoved of a furnace constructed in accordance with my Invention; a is the body
f the furnace made, say, of fire-clay; b is the space or chamber for the crucible
not shown); c represents the wire or strip coiled round against the sides of the

page_text: chamber; the ends of these wires pass through the furnace sides; d is the cover.
The wire or strip o should be much thicker at the ends in order to prevent
excessive heating at the point of exit from the furnace, where it should go direct to
some large body of conducting material to which it must be properly secured by
some metallic connection.
Figures 5 and 6 represent respectively in vertical section and in plan (with the
cover removed) a similar furnace in which the heating conductor is made of a short
bad conductor, and the material I prefer to employ for this conductor is a com-
bination of plumbago with some refractory earth, such as fire-clay, magnesia,
lime, &c. The proportions of plumbago and refractory earth are fixed according to
what specific resistance the compound is required to give; a is the body of the
furnace; b, the space or chamber for the crucible; c is the bad refractory conductor
forming a lining of the furnace; d is the cover or lid; k is part of the conductor of
comparatively low resistance and is made preferably of pure plumbago; m, m, are
metallic portions of the conductor to which are attached the conducting wires
P and N. The electric current passes from one conductor round both sides of the
furnace to the other conductor.
It will be seen that however expensive may be the source of the heat in these
furnaces, there will be a great econony in its development inasmuch as the largest
part of it will be utilized; there is not as in other furnaces a constant draught
through it bringing in cold and letting off heat.
By an evident modification the apparatus represented in Figures 3 and 4 may be
used for roasting meat and other like purposes.
In order to regulate the electric current so as to increase or diminish the supply
of light or heat, I join up in circuit an instrument constructed substantially as
represented in Figure 7, aud which I will now describe; a is a hollow cylinder of
glass or other suitable material fixed to a metallic base b; it is partly filled with
mercury or other suitable liquid up to about the height marked c; d is a tapered or
pointed rod made by preference of copper or silver and adjustable in the cover e
this rod is in metallic contact with the terminal f; g is the other terminal with
which the base b is in inetallic contact.
If a current pass from the terminal f to the base b, its flow can be regulated by
adjusting the height of the rod & so as to increase or diminish the resistance; if the
rod be lowered the resistance will be diminished; if it be raised the resistance is
increased. By making the rod twisted or spiral, as shown in the Figure, it offers a
higher resistance than if straight.
When a number of secondary batteries joined together in series are employed as
reservoirs for the electricity in a system of distributing currents by mains, branches,
and sub-branches, with returns by earth as described in the Specification of my
said former Letters Patent, I sometimes supply each of these reservoir batteries
with commutators and with the means of working them as will be well understood,
so that it will not be necessary to increase the electro-motive force in the mains in
order to charge them, but by merely coupling two or more parts or the whole
battery for quantity they can be charged with a low electro-motive force, and be
capable of giving by an alteration of the commutators the full tension when
required.
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
Application of Electricity to Lighting and Heating Purposes, and in the Means or
Apparatus employed therein,"
First. The employment for obtaining light by electricity of strips or wires
covered with earthy or vitreous material, as herein-before described.
Second. The employment for obtaining light by electricity of a continuous
conductor of asbestos or other non-conducting refractory material impregnated with
some refractory conducting material, as herein-before described.
Third. The means and apparatus substantially as herein-before described for
applying electricity to heating purposes.

page_text: Fourth. The instrument or apparatus constructed substantially as herein-before
described and represented in Figure 7, for regulating electric currents used for
lighting or heating purposes.
Fifth. The providing or fitting of commutators as herein-before described to
secondary batteries, when such batteries are employed as reservoirs of electricity in
a system of distributing electric currents by mains, branches, and sub-branches,
with returns by "earth."
In witness whereof, I, the said St. George Lane Fox, have hereunto set my
hand and seal, this Eighth day of April, One thousand eight hundred and
somontazmina
ST. G. LANE FOX. (L.S.)

page_text: Filed 10th January 1882.
"
In the Matter of Letters Patent granted to St George Lane Fox of
Telegraph Street in the City of London for the Invention for "IMPROVE-
MENTS IN THE APPLICATION OF ELECTRICITY TO LIGHTING AND HEATING
PURPOSES AND IN THE MEANS OR APPARATUS
THEREIN
EMPLOYED
dated the 12th day of October 1878 N° 4043.
DISCLAIMER AND MEMORANDUM OF ALTERATION entered by The
Anglo American Brush Electric Light Corporation Limited of Belverlere
Road Lambeth in the County of Surrrey the Assignees of the said Letters
Patent pursuant to the Statutes in that case made and provided
WHEREAS Letters Patent bearing date the 12th day of October 1878 and
numbered 4043 for the Invention of "IMPROVEMENTS IN THE APPLICATION OF
TO LIGHTING AND HEATING
ELECTRICITY
PURPOSES AND
THE
IN
MEANS OR
53
APPARATUS EMPLOYED THEREIN were granted to St. George Lane Fox his
executors, administrators and assigns for the term of 14 years next ensuing and
to which Letters Patent a specification was duly filed on the 12th day of April 1879
And whereas by an Indenture bearing date the 29th day of July 1881 and duly
entered in the Great Seal Patent Office the said St George Lane Fox assigned to the
Anglo American Brush Electric Light Corporation Limited the aforesaid Letters
Patent And whereas since the date of the said Letters Patent and of the filing of
the said Specification it has been discovered that certain parts of the said Invention
are of doubtful novelty and certain other parts are not of that utility which at the
date of the filing of the said Specification they were thought to possess. And The Anglo
American Brush Electric Light Corporation Limited the Assignees of the said
Letters Patent are for the above reasons desirous of entering a Disclaimer and
Memorandum of Alteration in respect of the said Letters Patent and of thereby
disclaiming certain portions of the title and the Specification filed thereto and of
making certain alterations therein Now know all Men that the said Anglo
American Brush Electric Light Corporation Limited therefore disclaim from the Title
of the said Invention the words "in the application of electricity to lighting and

page_text: .
"
"
heating purposes and" which follow immediately after the word "Improvements
and in lieu of the word "therein" in the said Title they insert the words "in the
application of electricity to lighting and heating purposes" so that the said title
shall stand as follows: "Improvements in the means or apparatus employed in
the application of electricity to lighting and heating purposes" and they disclaim
from the said specification, reference being had to the Queen's Printers printed
copy thereof, the following parts viz:-On page lines 5 and 6 the words "in the
application of electricity to lighting and heating purposes and" and on the same
page all the portion from the commencement of line 7 to the end of line 31 and on the
same page in line 45 the word "either" at the end of such line and on the same
page at line 46 the words from and including the word "or" to the end of such
line on page 4 all the portion from the commencement of line 24 to the end of
line 36 and on the same page line 48 the words "in the" at the end of such line
and the words "application of electricity to lighting and beating purposes and
in line 49 and on the same page all the portion from the commencement of line 51
to the end of line 55, ou page 5 all the portion from the commencement of line 1 to
the end of line 3 and also Figures 1, 2 and 7 in the sheet of drawings annexed
to the said specification And know further that the said Anglo American Brush
Electric Light Corporation Limited make the following alterations in the said
specification viz on page 3 line 6 they insert the words "in the application of
electricity to lighting and heating purposes in lieu of the word "therein " and
on page 4 in line 40 they leave out the word "said" and after the words "Letters
Patent" they insert the words "dated the 9th day of October 1878 N° 3988"
and on the same page they insert the words "in the application of electricity to
lighting and heating purposes instead of the word "therein" at the end of
line 50; and on the same page they insert the word "First" instead of the word
"Third" at the commencement of line 56; and on page 5 they insert the word
"Second" instead of the word "Fifth "at the commencement of line 4.
"
And the said Specification when so amended by Disclaimer and Memorandum of
Alteration will read as follows:-
"TO ALL TO WHOM THESE PRESENTS SHALL COME I ST GEORGE
"LANE Fox of Telegraph Street in the City of London Send Greeting
"WHEREAS Her Most Excellent Majesty Queen Victoria by Her Letters
"Patent bearing date the twelfth day of October in the year of Our Lord
"One thousand eight hundred and seventy eight in the forty second year of
"Her reign did for Herself, Her heirs and successors give and grant unto me
"the said St George Lane Fox Her special licence that I the said St George
"Lane Fox my executors administrators and assigns or such others as I the said
"S George Lane Fox my executors adininistrators and assigns should at any
"time agree with and no others from time to time and at all times thereafter
"during the term therein expressed should and lawfully might make use exercise
"and vend within the United Kingdom of Great Britain and Ireland the Channel
"Islands and Isle of Man an Invention for 'IMPROVEMENTS IN THE MEANS OR
" APPARATUS EMPLOYED IN THE APPLICATION OF ELECTRICITY TO LIGHTING AND
" HEATING
·
PURPOSES upon the condition (amongst others; that I the said
"St George Lane Fox my executors or adininistrators by an instrument in
"writing under my or their or one of their hands and seals should particularly
" describe and ascertain the nature of the said Invention and in what manner the
sane was to be performed and cause the same to be filed in the Great Seal
"Patent Office within six calendar months next and immediately after the date
" of the said Letters Patent NOW KNOW YE that I the said St George Lane
"Fox do hereby declare the nature of my said Invention and in what manner the
same is to be performed to be particularly described and ascertained in and by
"the following statement thereof, reference being had to the accompanying
"drawings that is to say:-
"
66
"In order to apply electricity to heating purposes a coil of fine wire may be
•

page_text: "used which will be heated in a greater or less degree when the electric current
passes through it. The intensity of the heat is determined by the length and
thickness of the wire or foil. Platinum is well suited to the purpose but iron
"will answer Or 1 use a larger conductor of some bad conducting refractory
"material such as carbon (preferably in the form of graphite) which in con-
junction with fire-clay or similar material may be made to form an inner lining
"of the furnace.
66
"For heating water the wire or foil is wound or otherwise arranged at the
"bottom of the receptacle in which the water is contained such receptacle being
"made of earthenware or other suitable material, the water becomes heated by
"the wire or foil. The wire or foil should of course be enameled or otherwise
"insulated or it may be kept apart from the water or substance to be heated by
a suitable diaphragm and immersed and surrounded by some insulating fluid,
"such as oil.
"
6
"For baking, heating rooms and other atmospheric heating the wire may be
"used plain and bare. Where very high temperatures are required such as for
"melting metals for example, I construct a furnace of the best non-heat
conducting material available, and I shape it internally to correspond with the
"form of the crucible to be heated. I coil or apply the heating conductors round
"the inner surface of the furnace and pass them out through the sides or bottom.
"Figures 3 and 4 are respectively a vertical section and a plan with the cover
removed of a furnace constructed in accordance with my Invention; a is the
"body of the furnace made, say of fire-clay; b is the space or chamber for the
"crucible (not shewn); e represents the wire or strip coiled round against the
sides of the chamber; the ends of these wires pass through the furnace sides;
"dis the cover. The wire or strip c should be much thicker at the ends in order
"to prevent excessive heating at the point of exit from the furnace, where it
"should go direct to some large body of conducting material to which it must be
"properly secured by some metallic connection.
* Figures 5 and 6 represent respectively in vertical section and in plan (with
"the cover removed) a similar furnace in which the heating conductor is made of
& short bad conductor, and the material I prefer to employ for this conductor is a
"combination of plumbago with some refractory earth such as fire-clay, magnesin,
"lime &c. The proportions of plumbago and refractory earth are fixed according
68 to what specific resistance the compound is required to give; a is the body of
"the furnace; the space or chamber for the crucible; c is the bad refractory
".conductor forming a lining of the furnace d is the cover or lid; is part of the
conductor of comparatively low resistance and is made preferably of pure
"plumbago; m m are metallic portions of the conductor to which are attached
"the conducting wires P and N. The electric current passes from one conductor
"round both sides of the furnace to the other conductor.
"It will be seen that however expensive may be the source of heat in these
"furnaces, there will be a great economy in its development inasmuch as the
"largest part of it will be utilized; there is not as in other furnaces a constant
draught through it bringing in cold and letting off heat.
"By an evident modification the apparatus represented in Figures 3 and 4 may
"be used for roasting meat and other like purposes.
"When a number of secondary batteries joined together in series are employed
as reservoirs for the electricity in a system of distributing currents by mains
"branches and sub-branches with returns by earth as described in the Specification
"of my former Letters Patent dated the 9th day of October 1878 N° 3988
"I sometimes supply each of these reservoir batteries with commutators and with
"the means of working them as will be well understood, so that it will not be
necessary to increase the electro motive force in the mains in order to charge
"them, but by merely coupling two or more parts or the whole battery for quantity
"they can be charged with a low electro-motive force and be capable of giving
"by an alteration of the commutators the full tension when required.
66

page_text: "
"And having now described the nature of my said Invention and in what
manuer the saine is to be performed I declare that I claim as my Improvements
"in the means or apparatus employed in the application of electricity to
lighting and heating purposes '
C
"First. The means and apparatus substantially as herein before described for
"applying electricity to heating purposes
"Second. The providing or fitting of commutators as herein before described to
"secondary batteries when such batteries are employed as reservoirs of electricity
" in a system of distributing electric currents by mains branches and sub-
"branches with returns by earth.'
$
"In witness whereof I the said St George Lane Fox have hereunto set my
"hand and seal this eighth day of April, One thousand eight hundred
"and seventy nine.
"ST. G. LANE FOX (L.S.)"
In witness whereof the said Anglo American Brush Electric Light Corporation
Limited have caused their common seal to be hereunto affixed the twenty
first day of December One thousand eight hundred and eighty one.
December 21st 1881
I hereby grant my Fiat giving leave to the above named Anglo American Brush
Electric Light Corporation, Limited, as Assignees of the said Letters, [sic] to file
in the Office of the Commissioners of Patents for Inventions, with the Specification
to which the same relates, the above written Disclaimer and Memorandum of
Alteration. Dated this 9th day of January 1882.
TAHO
3