IMPROVEMENTS IN APPARATUS FOR THE PRODUCTION OF ELECTRIC LIGHT
Year: 1880

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for an Invention of
"IMPROVEMENTS IN APPARATUS FOR THE PRODUCTION OF ELECTRIC LIGHT."
A communication from abroad by Thomas L. Clingman, of Asheville, North
Carolina, United States of America.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 5th May 1880.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN APPARATUS FOR THE
PRODUCTION OF ELECTRIC LIGHT." [A communication from abroad by Thomas L.
Clingman, of Asheville, North Carolina, United States of America.]
This Invention relates to the production of electric light. For this purpose I use
a small mass in the form of a sphere or spheroid, or an elongated cylinder with
convex ends, or a hemispherical mass. This mass is composed of the oxide of
zerconia, or of a mixture of zerconia and plumbago or other form of carbon, or of
zerconia and alumina, or magnesia, or lime, or silica, or mixtures with one or more
of these substances. The mass when thus composed of zerconia or plumbago or
other substance may also be covered with a thin coating or glazing of zerconia or
one of the other substances.
This mass or bead is to be supported on each side by wires or pins of platinum,
brass, iron, or other metal connected with copper or other metallic electrodes.
These pins when they are in contact with the zerconia mass may be in any
form, and may also be connected at several points or at only one point with. the
mass, and may be expanded at the point of contact.
I also in some cases provide openings through the mass in different directions to
admit air to affect the amount of heat at particular points.
Zerconia is the most infusable substance known, and is also a non-conductor of
electricity. Its want of conducting quality renders it incandescent under the
electric current when it is made to pass it.
Plumbago and other forms of carbon are, next to the metals, the best conductors,
but are combustible under high degrees of heat. When a mixture is made the

page_text: carbon gives conducting power to the electricity, while the surrounding zerconia
protects it from contact with the air. The carbon as well as the zerconia will thus
be rendered incandescent.
The outer coating of zerconia or other substance assists in more completely
excluding the air from the carbon. The carbon therefore is protected from combustion,
and it and zerconia being when heated the most highly incandescent substance
produce the best light. The size of the mass to be employed will influence the
proportion of the several mixtures.
The incandescence and light in the use of this Invention are produced by passing
electricity through and over the zerconia, and at the same time the carbon is
protected from contact with the air, and consequently from combustion, so that no
mechanism is necessary for feeding the carbon to supply waste.
By having openings when deemed necessary the presence of some air will tend
to cool the parts of the mass in contact with the platinum or other metal. The
central pin of the platinum may enter one of the openings larger than itself, and
thus will not be subjected to excessive heat.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Lake in the Great Seal Patent Office on the 5th
November 1880.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN APPARATUS FOR THE
A communication from abroad by Thomas L.
PRODUCTION OF ELECTRIC LIGHT."
Clingman, of Asheville, North Carolina, United States of America.
This Invention relates to the production of electric light. For this purpose I use
a small mass in the form of a sphere or spheroid, or an elongated cylinder with
convex ends, or a hemispherical mass. This mass is composed of the oxide of
zirconia, or of a mixture of zirconia and plumbago or other form of carbon, or of
zirconia and alumina, or magnesia, or lime, or silica, or mixtures with one or more
of these substances. The mass when thus composed of zirconia or plumbago or
other substance may also be coated exteriorly with a thin coating or glazing of
zirconia or one of the other substances above named.
This mass or bead is to be supported on each side by wires or pins of platinum,
brass, iron, or other metal connected with copper or other metallic electrodes.
These pins when they are in contact with the zirconia mass may be in any form,
and may also be connected at several points with the mass, as shown in the Drawing,
or only at one point, and may be expanded at the point of contact.
I also in some cases form openings through the mass in different directions to
admit air to affect the amount of heat at particular points.
Zirconia is the most infusable substance known, and is also a non-conductor
of electricity. Its want of conducting quality renders it incandescent under the
electric current when the latter is made to traverse it.
Plumbago and other forms of carbon are, next to the metals, the best conductors,
but are combustible under high degrees of heat. When a mixture is made the
carbon gives conducting power to the electricity, while the surrounding zirconia
protects it from contact with the air. The carbon as well as the zirconia will thus
be rendered incandescent.
The outer coating of zirconia or other substance assists in more completely
excluding the air from the carbon. The carbon therefore is protected from
combustion, and it and zirconia being when heated the most highly incandescent
substances produce the best light. The size of the mass to be employed will
influence the proportion of the several mixtures.
The incandescence and light in the use of this Invention are produced by passing
electricity through and over the zirconia mass, and at the same time the carbon is
protected from contact with the air, and consequently from combustion, so that no
mechanism is necessary for feeding the carbon to supply waste.
By having openings when deemed necessary the presence of some air will tend
to cool the parts of the mass in contact with the platinum or other metal. The
central pin of platinum may enter one of the openings larger than itself, and thus
will not be subjected to excessive heat.
In the accompanying Drawing,
Figures 1, 2, 3, and 4 represent the forms intended to be used.
A represents the zirconia mass or mixture; B, the platinum pins or wires; and
C, the electrodes of copper or other metal.
The pins B may be connected with the mass A by a single point enlarged
adjacent to the said mass, as shewn in Figure 1, or by several points, as shewn in
Figure 3.

page_text: Figure 4 represents the openings or air passages in different directions, in
one of which a wire point may be inserted in such a manner however as not to
fill it.
Figure 2 represents a central mass of greater non-conducting power, with
additions at the ends with greater conducting power.
The central mass may be formed by taking the zirconia in powder, as it is usually
obtained, and mixing it with the carbon or any of the other substances above
referred to, likewise in powder. The mixture may be moistened with any adhesive
liquid and moulded to the shape desired.
In some cases the mass may be made by moulding the central portion into the
shape of a cylinder composed chiefly of zirconia or of zirconia alone, and after it
has been dried there may be attached to its ends pieces having a greater portion of
the conducting substance, so as to cause less heat at the ends in contact with the
platinum or other substance used to support it.
After the mass has been dried it may, when desired, have a thin coating of
zirconia or any of the other substances referred to applied to its exterior, as above
described, to cover it either entirely or partially.
The openings in the mass whenever it is desirable to use them can be made by
moulding the mass around a piece of wire or a small rod which, after drying, can be
drawn out, or they can be produced by moulding the mass around a small cylinder
of hard smooth wood, or even a straw, which will in the baking of the mass be
burnt out and leave hollow spaces.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,
The mass composed of the substance or substances above specified combined with
the wires or points of platinum or other metal and the electrodes, substantially as
above described with reference to the Drawing, and for the purpose set forth.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Fourth day of November, in the year of our Lord
One thousand eight hundred and eighty.
W KUB LAKE. (L.S.)