Year: 1898

page_text: A communication from CARL PIeper, of Hindersinstrasse, 3, Berlin, Germany,
Patent Agent.'
I, WILLIAM LLOYD WISE, of 46, Lincoln's Inn Fields, in the County of London,
Consulting Engineer and Chartered Patent Agent, do hereby declare the nature of
this invention to be as follows;-
This invention has for object the manufacture of electric glow lamps having a
greater illuminating power, with the same consumption of energy, or requiring a
less consumption of energy with the same illuminating power than the electric glow
lamps heretofore usually employed.
For this purpose the lamp conductor or filament is covered or coated with metallic
oxides which have a high-light-emitting power. This is effected in the most suit-
able manner by employing as the glow filament, the metals whose oxides are to
form the luminous surface, or an alloy of the said metals. The electrical furnace
is most suitable for the production of such alloys. The air that remains in the
imperfectly-exhausted lamp bulb or glass receiver will suffice to coat the said
metallic glow filament with a sufficient film of oxide when an electric current is
passed through the filament.
1.1
T
1000
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.
A communication from CARL PIEPER, of Hindersinstrasse, 3, Berlin, Germany,
l'atent Agent.
I, WILLIAM LLOYD WISE, of 46, Lincoln's Inn Fields, in the County of London,
Consulting Engineer and Chartered Patent Agent, 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:—
This invention has for object the manufacture of electric glow lamps having a
greater illuminating power, with the same consumption of energy, or requiring a

page_text: less consumption of energy with the same illuminating power as compared with
the electric glow lamps heretofore usually employed.
For this purpose the lamp conductor or filament is covered or coated with a
metallic oxide or oxides which has or have a high light-emitting power. This is
effected by employing as the glow filament a metal whose oxide is to form the
luminous surface, or an alloy of two or more such metals. The electric furnace
is suitable for the production of such alloys.
On placing the incandescence body into an imperfectly exhausted glass bulb.
the residual air therein is sufficient to oxidise the surface of the metal or alloy
as soon as an electric current is passed through the said body sufficient to raise it
to a suitable oxidising temperature. In this manner there is obtained a body
whose core is composed of non-oxidised metal or alloy but whose surface consists
of metallic oxide or oxides.
Thorium and an alloy or alloys of thorium with one or more of the metals of
the platinum group have been found to be particularly suitable for the production 1
of the hereinbefore described glow filaments or bodies.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is;-
The manufacture of glow filaments or bodies for electric glow lamps by forming
the filaments or bodies of a metal or an alloy of metals whose oxide or oxides has
or have a high light-emitting power, and oxidising the surface of the same by
glowing in the presence of air.
Dated this 1st dos of Nba 1000
Deted this 1st day of November 1900.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.