Improvements in or connected with the Manufacture of Carbons for Electric Arc Lamps.
Year: 1898

page_text: Date of Application, 15th Mar., 1898
Complete Specification Lett; 15th Dec., 1898-Accepted, 21st Jan., 1899
PROVISIONAL SPECIFICATION.
Improvements in or connected with the Manufacture of Carbons for
Electric Arc Lamps.
I, JOIN JARL WADDINGTON, of 79, Hugh Street, Eccleston Square, in the County
of London, Engineer, do hereby declare the nature of this invention to be as
follows:-
I
My invention has for its object to render the light produced in an electric arc
lamp of a more pleasing colour to the eye, to increase the lighting power, to render
the light richer in certain rays useful in photography, and to increase its power
of fog penetration.
According to my invention I take a rod of carbon such as is now ordinarily used
in electric arc lamps and I form a hole or boring at the centre thereof which shall
pass through the entire length of the said carbon. The hole or boring is filled
with plaster of Paris, or such other material or mixture which when brought
to a state of incandescence will render the arc luminous and possessed of valuable
light giving rays. The material used for filling the hole or boring in the carbon
rod may be adapted to the particular purpose for which the light is needed.
Dated this 15th day of March 1898.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.
Improvements in or connected with the Manufacture of Carbons for
Electric Arc Lamps.
I, JOHN JARL WADDINGTON, of 79, Hugh Street, Eccleston Square, in the County
of London, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement:-
My invention has for its object to render the light produced in an electric are
lamp of a more pleasing colour than has hitherto been the case, to increase the
lighting power, to render the light richer in certain rays useful in photography,
and to increase its power of fog penetration.
According to my invention I form, by boring, or otherwise, an axial hole through
a rod of carbon such as is now ordinarily used in electric arc lamps, or through
so much of the said rod as is to be consumed, and I fill the said hole with plaster
of Paris, or such other material, or mixture of materials, as will, when brought
to a state of incandescence in the arc lamp, become luminous and impart thereto
D917

page_text: valuable light giving rays. The said material, or mixture of materials, will be
selected in accordance with the particular purpose for which the light is needed;
I give the following instances of materials which I have found to answer.
Where the object is to give a more pleasing colour to the light, oxide of
strontium mixed with plaster of Paris and carbon dust makes a suitable material
to employ for the core and this also is suitable when the light is to be used for
photographic purposes, especially for photographing black and white "copy,"
but where red "copy" is to be photographed plaster of Paris, or oxide of calcium
will afford the richness of rays desirable. For fog penetration, search lights, or the
like, sodium carbonate mixed with plaster of Paris is a suitable material affording
a light rich in the rays desirable for these purposes.
A convenient way of making the carbons according to my invention is to bore
the hole through the axis of the ordinary carbon and then to form the material,
or mixture of materials, to be enclosed in the said hole (say strontium, carbon dust
and a small quantity of plaster of Paris, for example,) into a plastic, or pasty,
state by admixture with water, and then to insert small portions at a time of the
paste, so formed, into the said hole ramming each portion well down by means of
a ram-rod fitting the hole.
:
Having now particularly described and ascertained the nature of this invention,
and in what manner the same is to be performed, I declare that what I claim is:-
'
-
For electric arc lamps, a carbon having a core of a material or mixture of
materials, which will be brought, when in the arc, to a state of incandescence;
substantially as, and for the purposes, herein before described.
Dated this 15th day of December 1898.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.