IMPROVEMENTS IN THE MANUFACTURE OF LIGHT EMITTING CONDUCTORS FOR ELECTRIC LIGHTING PURPOSES AND IN APPARATUS THEREFOR, WHICH APPARATUS IS ALSO APPLICABLE FOR OTHER PURPOSES
Year: 1882

page_text: LETTERS PATENT to Richard Werdermann, of Princes Street in the County
.
of Surrey Civil Engineer, for an Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF LIGHT EMITTING CONDUCTORS FOR ELECTRIC LIGHTING
PURPOSES AND IN APPARATUS THEREFOR, WHICH APPARATUS IS ALSO
APPLICABLE FOR OTHER PURPOSES,"
PROVISIONAL SPECIFICATION left by the said Richard Werdermann at the
Office of the Commissioners of Patents on the 5th August 1882.
RICHARD WERDERMANN, of Princes Street, in the County of Surrey, Civil
Engineer "IMPROVEMENTS IN THE MANUFACTURE OF LIGHT-EMITTING CONDUCTORS
FOR ELECTRIC LIGHTING PURPOSES AND IN APPARATUS THEREFOR, WHICH APPARATUS
IS ALSO APPLICABLE FOR OTHER PURPOSES
"
My Invention relates to the manufacture of light-emitting conductors either for
are lamps or for incandescent lamps, and to apparatus chiefly designed to be
employed in such manufacture.
In electric lighting apparatus the rheophores or light-emitting parts of the
circuit which generally consist of carbon are more or less rapidly consumed either
by oxidation or by volatilization.
According to my said Invention I use, instead of carbon, crystallized silicium or
graphitoïdal silicium. These allotropic modifications of silicium do not oxidize at
white heat in oxygen or oxygen compounds, except in carbon compounds rich in
oxygen, as, for instance, carbonic acid.
Silicium is obtained by chemical processes in the crystallized or graphitoïdal
modification, only in the form of small needles or hexagonal prisms or laminæ and
as in these forms it is not suitable for use in electric lamps, I fuse the same and
cast it in moulds in the form of pencils, bars, threads, or buttons, or other desired
form.
During the process of smelting it must be carefully preserved from contact with
carbonic acid; I therefore either smelt it in a platinum crucible under a cover of

page_text: caustic lime, or I smelt it together with zinc, and after having volatilized the latter
I cast the silicium in the moulds. But I prefer to smelt the silicium by the electric
current in the following manner, that is to say;-a mould made of non-conducting
material is closed at the bottom by a metallic plug which forms a part of, or is
attached to, the lower plate of a hydraulic or other press and is connected with one
pole of a generator of electricity. After having filled the mould with silicium
I close the top of the same by means of a cylindrical rod or piston which is fixed to
or forms a part of, the upper plate of the said press and is connected with the other
pole of the source of electricity. I then send a powerful current through the
silicium in order to heat the same to red or white heat or to fuse it, and at the
same time I compress it. After cooling I take the silicium out of the mould and it
is then ready to be used for the production of the electric light either in connection
with regulator or arc lamps, or with the so called incandescent lamps. The above
described apparatus may also be employed for fusing and compressing other metals
to obtain castings of great density.
As silicium is not oxidized by the oxygen contained in the atmosphere, it is not
necessary to use a vacuum globe, but when it is to be used in places where the air
contains carbonic acid it is better to protect the silicium by an air-tight cover.
The silicium may, if desired, be placed in a transparent tube of any highly
refractory material and a current of electricity passed through the same in any
suitable manner, in order to bring the silicium to incandescence. The said tube
may be bent in horseshoe or other form as desired.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Richard Werdermann in the Great Seal Patent Office on the
5th February 1883.
RICHARD WERDERMANN, of Princes Street in the County of Surrey, Civil
Engineer "IMPROVEMENTS IN THE MANUFActure of lighT-EMITTING CONDUCTORS
FOR ELECTRIC LIGHTING PURPOSES, AND IN APPARATUS THEREFOR, WHICH APPARATUS
IS ALSO APPLICABLE FOR OTHER PURPOSES "
My invention relates to the manufacture of light-emitting conductors either for
are lamps or for incandescent lamps, and to apparatus chiefly designed to be
employed in such manufacture:
In electric lighting apparatus the rheophores or light-emitting parts of the
circuit, which generally consist of carbon, are more or less rapidly consumed either
by oxidation or by volatilization.
According to my said invention I use, instead of carbon, crystallized silicium or
graphitoidal silicium. These allotropic forms or modifications of silicium do not
oxidize at a white heat in oxygen or its compounds, except in carbon compounds,
for instance carbonic oxide or carbonic acid. Silicium is obtained by chemical
processes in the crystallized or graphitoidal modification only in the form of small
needles or hexagonal prisios or lamine, and as in these forms it is not suitable for
use in electric lamps I fuse the same and cast it in suitable moulds in the form
of pencils, bars, threads, buttons, or otherwise as desired.
During the process of melting, the silicium must be carefully preserved from
contact with carbonic acid. I may either melt it in a platinum crucible under a
cover of caustic lime or I melt it with zinc, and after having volatilised the latter
I cast the silicium in the moulds. But I prefer to melt the silicium by an electric
current for which purpose I use the apparatus shewn in sectional elevation in
the drawing. This apparatus has a mould a made of non-conducting material and
closed at the bottom by a metal plug b; this plug forms a part of, or is attached
to, the lower plate of a hydraulic or other press and is connected with one pole
of a generator of electricity.
In using this apparatus I proceed as follows, that is to say. After having filled
the mould a with silicium I close the top of the same by means of a cylindrical
rod or piston c which is attached to, or forms a part of, the-upper plate of the
said press and is connected with the other pole of the said generator or source
of electricity. I then send a powerful current through the silicium to fuse the
same or heat it to a red or white heat while at the same time the piston is operated
to effect its compression After cooling the silicium, or allowing it to cool, I remove
it from the mould and it is then ready to be used for the production of electric light
either in connection with regulators or arc-lamps or with the so-called incandescent
lamps. The above described apparatus may also be employed for fusing or melting,
and compressing, other metals or carbon to obtain castings, or pencils, or rods of
great density.
As silicium is not oxidized by the oxygen of the atmosphere it is not necessary
to provide a vacuum globe for the lamps in which it is used, but when it is to be
used in places where the air contains carbonic acid I prefer to protect the silicium
by an air-tight cover.
These silicium conductors when used, may, if desired, be placed in a transparent
tube of any highly refractory material and may have a current of electricity passed
through the same in any suitable manner, in order to bring the silicium to
incandescence. The said tube may be bent to a horseshoe or other form as desired.
Having thus fully described my said invention and the manner of performing
the same I wish it understood that I claim

page_text: First. The manufacture substantially as set forth of crystallized or graphitoidal
silicium conductors for the production of electric light.
Second. In the manufacture of my improved conductors (or for melting metals
or heating carbon under pressure for various purposes) the use of apparatus sub-
stantially such as that shewn in the drawing in connection with a generator or
source of electricity substantially as set forth.
'
In witness whereof I the said Richard Werdermann have hereunto set my
hand and seal this Fifth day of February in the year of our Lord One
thousand eight hundred and eighty three.