AN IMPROVED METHOD OF AND APPARATUS FOR PRODUCING ELECTRIC LIGHT, AND REGULATING OR CONTROLLING AND MEASURING ELECTRICAL CURRENTS FOR LIGHTING, TELEGRAPHING, AND OTHER PURPOSES
Year: 1878

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5
PROVISIONAL SPECIFICATION left by Silvanus Frederick Van Choate at the
Office of the Commissioners of Patents on the 31st October 1878.
SILVANUS FREDERICK VAN CHOATE, of the City and State of New York,
United States of America, but now of 8, Southampton Buildings, London,
Electrician and Telegraphic Engineer. "AN IMPROVED METHOD OF AND
APPARATUS FOR PRODUCING ELECTRIC LIGHT, AND REGULATING OR CONTROLLING
AND MEASURING ELECTRICAL CURRENTS FOR LIGHTING, TELEGRAPHING, AND OTHER
PURPOSES."
•
My Invention relates to a novel method and apparatus chiefly designed for use
in electric lighting, but which is also partly applicable for telegraphic and other
electrical purposes.
My Invention relates partly to an improved illuminator or apparatus for
developing light from an electric current.
The substance or material which I employ to form my illuminator or burnor, and
which is to give the illumination by the action of the electric influence, is composed
or formed of asbestos, mica, platinum, or carbon, or any combination of them, and
such other materials as may be required to give the proper affinity and homo-
geneousness to the material. These materials are mixed and prepared to form a
metallic or semi-metallic material which becomes incandescent under the influence
of electricity and gives or forms the illumination, but which practically speaking
does not volatilize, melt, or fuse under the influence of the electric current.
This metallic or semi-metallic substance or material is, preferably, made into
wire or ribbon of proper size, and formed into arcs, spirals, or spiral globe-shaped
illuminators or burners, or the material may be formed into discs, or globes, or
spirals wound around a central wire or body or into other shapes required to form
the light. The same will be placed or inserted at the desired point or points in the
electric circuit in which it is desired to produce the light; and when these illumi-
nators are placed in proper position, the light can be produced by turning the
electricity through them; and to extinguish the light the electricity has simply
to be turned off. By the employment of my illuminator the necessity of changing

page_text: or inserting new burners, cokes, carbons or other devices at intervals is entirely
obviated.
The object of another part of the said Invention is to afford the means for
regulating, controlling, and measuring the flow or passage of the electric current
through a circuit or conductor in such a manner that the light or other effect or
developement of the electricity at any point or points in the said circuit may be
kept or maintained at a uniform or steady rate or flow, and also may be increased
or diminished without decreasing, diminishing, or otherwise disturbing the light or
effect at other points in the said circuit. The said Invention will therefore be of
very great importance for electric lighting, as it provides the means, whereby in a
circuit of any number of lights each light may be rendered independent of the
other lights to such an extent that the lights may be caused to burn with an equal
and uniform brilliancy, and one or any number of the said lights may be
extinguished without extinguishing or in anywise disturbing the other lights in
the said circuit.
In carrying this part of my Invention into practice for electric lighting, I first
ascertain or determine the number and power of the lights, lamps, or illuminators
to be used in each circuit, I then ascertain and determine the amount of electrical
resistance that will be required at each lamp or point of illumination to produce
the electric arc or light, that is to say, the amount of resistance necessary to render
incandescent the carbon, metal, or other substance used for giving or developing the
light. The sum of these quantities of resistance added to the resistance of the
wire or conductor will be the total resistance in the circuit, that is to say, the
strength of the electrical current required to be generated to produce the desired
number and intensity of the lights.
The peculiar feature of this part of my Invention consists in dividing the main
conductor or circuit into two conductors at each point along its length, where the
illuminators, lamps, or lights are to be placed by throwing out a loop or branch
conductor from the main one, and this branch or loop I call the secondary or
auxiliary conductor, and in combining with this double or divided conductor an
adjusting piece so arranged that the whole or any part of the current may be
caused to pass either through the branch or auxiliary conductor in which the light
is included, or through the other main conductor, and these two conductors and
adjusting piece are so arranged with proper resistances, that in whatever position
the said piece is adjusted the sum of the force or amount of the current passing
through the divided conductor or the two branches of the main conductor will not
be changed by the adjustment of the said adjusting piece, that is to say, the
quantity or amount of the electric current diverted by such adjustment from one
of the two conductors or branches will be exactly equalled by the increased
quantity thereby caused to pass through the other conductor or branch.
I effect this result as follows, that is to say:-I divide the main conductor and
circuit at or near the lamp or burner, or at the point where the illuminator is to be
placed into two branches or conductors. One of these conductors includes the
carbon, or metal, or other substance by whose illumination or incandescence the
light is given, and the other conductor passes on and the two branches are brought
together or re-united beyond or at a point adjacent to the lamp or lighting point,
or at any other convenient or desired position.
At one or both of the junctions or uniting points of this divided or double
conductor I arrange the switch, shunt, key; tap, or other suitable adjusting piece or
current changer or conductor divisor fitted to work on a fulcrum or pivot, or to
slide or otherwise, so arranged in connection with fixed plates, pieces, or points of
contact in both parts of the said double or divided conductor that it can be moved
to and fro or otherwise from one to the other, and provided with insulations and
resistances as required. By the adjustment of the said switch and the adjusting
piece as to resistances and otherwise, the flow or passage of the electric current is
regulated to. cause the said current or any desired proportion of the same to pass
either through the carbon, metal, or other substance, which gives the light or on

page_text: through the main conductor, that is to say, I can by the adjustment of the said
switch or adjustable piece divert more or less of the current from the main circuit
and conductor to any one of the said lamps or burners or illuminating points, or
from the latter into and through the inain circuit or conductor, and thereby
diminish or increase the intensity of the light at such point without disturbing or
affecting any or either of the other lights in the main circuit or conductor. With
this arrangement the lights will remain practically unaffected by any fluctuations
of the current through the main conductor.
I prefer to have the adjusting piece graduated or marked with a scale of divisions,
or to have a pointer or index arranged in connection with a scale of divisions on
the fixed plates or contact or connecting pieces of the two circuits or conductors,
with which the said adjusting piece is combined as above described for measuring
the currents passing through it, or within the said main circuit or the branch
thereof, or suitably connected with the same I may insert a meter or device for
determining and indicating the amount and force of the electric current sent
through the said circuit, or the lamps, burners, or other points of resistance in
the same.