IMPROVEMENTS IN PRODUCING AND REGULATING ELECTRIC LIGHT
Year: 1878

page_text: LETTERS PATENT to Henry Wilde, of Manchester, in the County of Lan-
caster, Engineer, for the Invention of "IMPROVEMENTS IN PRODUCING AND
REGULATING ELECTRIC LIGHT."
aled the 18th October 1878, and dated the 17th August 1878.
PROVISIONAL SPECIFICATION left by the said Henry Wilde at the Office
of the Commissioners of Patents on the 17th August 1878.
HENRY WILDE, of Manchester, in the County of Lancaster, Engineer. "IM-
PROVEMENTS IN PRODUCING AND REGULATING ELECTRIC LIGHT."
My Invention consists in a method of burning the carbon pencils used for pro-
ducing electric light in such a manner that the regulating mechanism usually
employed for maintaining the carbon points at a proper distance from each other is
dispensed with.
In this improvement the two carbon pencils are placed parallel to each other
and are fixed in separate holders.
The carbon holders are fixed to a base of wood or other non-conducting material,
and are so constructed that the distance of the carbons from each other may be
adjusted to any degree of closeness without the holders coming into metallic
contact.
The carbon holders are connected respectively with the polar terminals of one of
the electro-magnetic machines producing alternating currents for which Letters
Patent were granted to me on the 23rd day of March 1867, No. 842, or with the
machines for which Letters Patent were granted to me on the 1st day of December
1863, No. 3006, and on the 26th day of October 1865, No. 2762, which two last
Patents have been extended.
When the light is required, the circuit is completed between the carbon points
by a solid conducting substance or by a paste composed of carbon mixed with oil
or gum.

page_text: The strength of the electric current and the thickness of the carbons and their
distance apart are so proportioned that the light is produced from the upper
extremity of the carbons which burn downwards with regularity until they are
consumed.
Several of such electric lights may be placed in the same circuit.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Henry Wilde in the Great Seal Patent Office on the 2nd Novem-
ber 1878.
HENRY WILDE, of Manchester, in the County of Lancaster, Engineer.
PROVEMENTS IN PRODUCING AND REGULATING ELECTRIC LIGHT."
"IM-
My Invention consists in a method of burning the 'carbon pencils used for pro-
ducing electric light in such a manner that the regulating mechanism usually
employed for maintaining the carbon points at a "per distance from each other is
dispensed with.
In this improvement the two carbon pencils are placed parallel to each other,
and are fixed in separate holders.
The carbon holders are fixed to a base of wood or other non-conducting material,
and are so constructed that the distance of the carbons from each other may
be adjusted to any degree of closeness without the holders coming into metallic
contact.
The carbon holders are connected respectively with the polar terminals of one of
the electro-magnetic machines producing alternating currents for which Letters
Patent were granted to me on the 23rd day of March 1867, Number 842, or with
the machines for which Letters Patent were granted to me on the 1st day of
December 1863, No. 3006, and on the 26th day of October 1865, No. 2762, which
two last Patents have been extended.
When the light is required the circuit is completed between the carbon points
by a solid conducting substance, or by a paste composed of carbon mixed
with gum.
The strength of the electric current and the thickness of the carbons and their
distance apart are so proportioned that the light is produced from the upper
extremity of the carbons which burn downwards with regularity until they are
consumed.
Several of such electric lights may be placed in the same circuit.
And in order that my Invention may be fully understood and readily carried into
operation, I will proceed to describe the accompanying Sheet of Drawings, in
which Fig. 1 is a front elevation, and Fig. 2 a side view of my improved apparatus
for producing and regulating electric light.
a and bare the carbon pencils, which are fixed parallel to each other in the
separate spring holders c and d, which are made of brass; the holders are fixed to
the base e, which is made of wood or other non-conducting material. The distance

page_text: between the carbon pencils may be adjusted to any degree of closeness, without the
holders coming into metallic contact. The lower ends of the carbon pencils, which
may be of any convenient length, are contained in the tube f, at the bottom end of
which is a piston g, made of wood or other non-conducting substance fitting loosely
in the tube, this piston is forced upwards, when required, to keep the point of light
at the proper distance above the holders.
To prevent the lower ends of the carbons from coming into contact with each
other, I place a thimble of ebonite or other insulating material on the end of one of
the carbons, as shewn in Fig. 1.
To the holder c is fixed the short tube h, the object of which is to indicato by
occulting the light when the carbon pencils require raising.
The carbon pencils may be held between antifriction rollers in the spring clips.
The holders are connected respectively with the polar terminals of a magneto-
electric or an electro-magnetic induction machine, producing alternating currents.
When the light is required, the circuit is completed between the carbon points by
a solid conducting substance, or by a paste composed of carbon mixed with gum;
or the carbon points may be brought together automatically to establish the circuit
in the following manner:-The holder d is binged at ď¹ to a metal plate d² fixed
in the insulated base e, and a spring d³ is placed between the holder and the base;
the object of this spring is to bring the points of the carbon pencils into contact when
no current is transmitted through the carbons, as shewn in dotted lines in Fig. 1.
A small electro-magnet i is fixed in the base e, or in any other suitable position.
The coils of this electro-magnet are placed in the same circuit as the light-producing
current, and the electric circuit is completed through the points of the carbons and
the holders c and d.
When the current is transmitted through the carbons, the electro-magnet i attracts
a soft iron armature d' fixed to the under side of the hinged holder d, and separates
the upper ends of the carbons, thereby bringing the carbons into their parallel
position and producing the light; when the electric circuit is interrupted from any
the armature is released from the electro-magnet, and the circuit is re-established
through the points of the carbons as before.
cause,
The spring d³ may be dispensed with by weighting the holder d, so that the points
of the carbons may be brought into contact by gravity.
In this method of producing the electric light from carbon pencils, the strength
of the electric current, and the thickness of the carbons, and the distance between
them must be in the proper relative proportions to produce the desired result; the
Drawing represents carbons three-sixteenths of an inch in diameter, and one-eighth
of an inch apart, which are acted upon by an electric current of the strength required
for fusing an iron wire of No. 22 Birmingham wire gauge, equal to three-hundredths
of an inch in diameter, and four feet in length, and the length of the electric
arc must always exceed the distance between the centres of the points of the
carbons.
When smaller carbons are used, the electric currents must have the same intensity
as for larger carbons, but not the same quantity; thus for carbons seventeen-
hundredths of an inch in diameter the current should only be sufficient to fuse
an iron wire of No. 25 Birmingham wire gauge, or two-hundredths of an inch in
diameter.
When the light is produced from large carbons and powerful electric currents, the
cylindricals form is unsuitable on account of the distance between the centres of the
points, and to obtain good results from large carbons, I make them in the form
of parallelopipedons, as shewn in Fig. 3, by which means the centres of the
carbons are brought sufficiently close to each other to allow a short electric arc to
pass between them.
When the carbons are very small in diameter, the light may be produced from
them by secondary electric currents generated in induction coils in the manner
described in the Specification of Letters Patent granted to me on the 28th day of

page_text: March 1878, No. 1228; by this means the electric light may be subdivided to a great
extent, and many electric lights may be placed in the same circuit.
By the methods of producing electric light from carbon pencils placed parallel to
each other, as herein described, the insulating material hitherto used with
them is dispensed with, and the carbons will burn downwards with regularity.
Having thus stated the nature of my Invention and described convenient modes
of carrying the same into operation, I wish it to be understood that I do not
limit myself to the details and proportions given, and that what I claim is,―
First. Producing electric light from parallel carbon 'pencils by proportioning the
strength of the electric current to the thickness of the carbons and their distance
apart, as shewn and described:
Secondly. The method of bringing together and separating automatically the
upper ends of carbon pencils placed parallel to each other for producing the light, as
shewn and described.
Thirdly. The method of raising parallel carbon pencils through the holders, and
enclosing them, as shewn and described.
And, Fourthly. The occultation of the light by a tube or other equivalent, as
shewn and for the purpose described..
:
İn witness whereof, I, the said Henry Wilde, have hereunto set my hand
and seal, this First day of November, One thousand eight hundred and
seventy-eight.
HENRY WILDE. (L.S.)