Improvements in Incandescence Bodies suitable for Use with Gas and other Burners.
Year: 1899

page_text: Date of Application, 25th Feb., 1899
Complete Soecification Left. 27th Nov. 1899-Accepted. 6th Jan. 1900
PROVISIONAL SPECIFICATION.
Improvements in Incandescence Bodies suitable for Use with Gas and
other Burners.
I, JOHN HENRY HILL DUNCAN, of 39, Coleman Street, in the City of London,
Chartered Accountant, do hereby declare the nature of this invention to be as
follows:-
According to this invention, incandescence bodies suitable for use with gas
and other burners are made of thoria, alumina and chromic oxide in or about
the proportion of 50% thoria, 40% alumina, and 10% chromic oxide though
these proportions may be varied to some extent.
Such incandescence bodies can be produced in various ways, as for example
by impregnating suitable threads or fabric with salts of the substances mentioned
and then converting such salts into the said oxides by heating or otherwise
treating the impregnated threads or fabrics in the usual or any suitable way;
or by mixing the said salts with collodion or other material that is afterwards
converted into threads which are suitably fixed and formed by weaving or other-
wise into incandescence bodies of any suitable shape and igniting them as well
understood; or by any other process which results in the production of suitable
filaments of oxides.
Improvements in Incandescence Bodies suitable for Use with Gas and
other Burners.
I, JOHN HENRY HILL DUNCAN, of 39, Coleman Street, in the City of London,
Chartered Accountant, 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:-
According to this invention, incandescence bodies suitable for use with gas
and other burners are made of thoria, alumina, and chromium oxide in or about
the proportion of 50% thoria, 40% alumina, and 10% chromium oxide though
these proportions may be varied to some extent.
Such incandescence bodies can be produced in various ways, as for example

page_text: by impregnating suitable threads or fabric with salts of the substances mentioned
and then converting such salts into the said oxides by heating or otherwise
treating the impregnated threads or fabrics in the usual or any suitable way;
or by mixing the said salts with collodion or other material that is afterwards
converted into threads which are suitably fixed and formed by weaving or other-
wise into incandescence bodies of any suitable shape and igniting them as well
understood; or by any other process which results in the production of suitable
filaments of oxides.
When incandescence bodies in accordance with this invention are prepared by
the now well known impregnation process, the thorium, aluminium, and
chromium, which are to be in the form of oxides in the finished body, may be
added to the impregnating solution as thorium nitrate, aluminium nitrate and
chromic acid in such proportions that the thoria, alumina and chromium oxide
present in the mixture will be in or about the proportions herein before
mentioned.
When the incandescence bodies are made from filaments or threads produced
from a mixture containing collodion or some other solution of a combustible
substance, the herein before mentioned thorium nitrate, aluminium nitrate, and
chromic acid may be dissolved in a solvent of the combustible substance and in
that form be added to the collodion or other solution of a combustible substance.
Although the above mentioned proportions of the various substances used, if
strictly adhered to, give most satisfactory results with the methods of manu-
facture and burning off now in-use, yet it is not intended to limit the scope of
-this invention rigidly thereto, as the proportion of thoria may be varied con-
siderably so long as the alumina and-chromium oxide are retained in the rela-
tive proportions mentioned, or in variations of the same that will allow of or..at
least will not prejudice the chemical combination of these two substances.
"Having now-particularly described and ascertained the nature of the said in-
vention and in what manner the same is to be performed_I_declare that what I
claim is:
An incandescence body, suitable for use with gas and other burners, made of
thoria, alumina and chromium oxide substantially in or about the proportions
set forth.
IUI UII.
Dated this 27th day of November 1899..
For the Applicant,
W. LLOYD WISE,
:
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.