Improvements in incandescent Gas Lighting.
Year: 1894

page_text: Date of Application, 5th Sept., 1894
Complete Specification Left. 5th June, 1895-Accepted, 5th Sep... 1895
Improvements in incandescent Gas Lighting.
A communication from CHARLES MARSHALL LUNGREN, of West Street, New
York, United States of America, Gas Engineer.
I, HERRMANN FRIEDLANDER, of Royal Hotel, Blackfriars London, Merchant,
do hereby declare the nature of this invention to be as follows:-
This invention relates to the manufacture of the bodies or frames placed over gas
burners which become incandescent by the heat from the lighted gas. The incan-
descent bodies as now made are produced from various earths by saturating an
open-meshed textile fabric with the solution or emulsion of such earths, and
incinerating the fibre. They however present the defect that the composition of
the materials gives a peculiar greenish white colour and makes the light unsuitable
for some purposes, and moreover the method of manufacture adopted makes these
articles extremely delicate, so that they readily break or become damaged and hence
unfit for use.
Incandescent bodies produced according to the present invention are free from
these defects. The light yielded where they are used has a yellow warm tint
of daylight, pleasing to the eye, and the method of manufacture is such as to
make them more durable and capable of greater resistance than those hereinbefore
known.
For producing these incandescent bodies according to the present invention a
mixture of the oxides of thorium, lanthanum and didymium is used. Suitable
proportions are as follows:-
Oxide of thorium.
Oxide of didymium
Oxide of lanthanum
-
This gives a white light with a slightly yellow tinge.
96-98 per cent..
1-2 "
"
1-2. "
"
The proportion of the didymium causing the yellowness, must be small as this
substance causes a considerable colouration of the light. The proportion of
lanthanum may if desired be increased. Thorium oxide makes the article capable
of resistance and durable. Lanthanum oxide may however be wholly or in part
substituted therefor without sacrifice of that advantage. Thus 98 per cent. of.
lanthanum oxide and 2 per cent. of didymium oxide may be employed in the manu-
facture. By increasing the proportion of didymium oxide the colour of the light
is made more yellow. About 5 per cent. will probably be the limit of such
addition.
The manufacture of such bodies for incandescence from the oxides of thorium,
lanthanum, and didymium, or of those of lanthanum and didymium alone, is
effected as follows:-The materials are finely pulverised and mixed in above
indicated proportions and then made into a dough or paste by a suitable cementitious
material, say liquid glue for instance. The dough or paste is forced out from a
press, in a thread or threads which is, or are afterwards woven into a net, and from
that the tapering cap, like bodies are made which by suitable holders are fixed over
the flame of a gas burner.
By adding glycerine to the said dough or paste, it is kept elastic after it is
pressed out to the desired shape, and will not readily become hard and brittle. The
037

page_text: net-like structure made as above is next dried and then burnt to remove the glue or
other cement, and this makes the threadlike material hard and rigid. To burn the
net, cap, or article, it is put on a mould corresponding to the shape required, con-
sisting of platinum wire or other fire-proof material say porcelain, clay, or fire-clay;
and the cap and mould heated to such a degree as to entirely remove the lime or
the like. The material of the article is then hard and firm and can be handled for
fixing on the burner without falling to pieces.
Dated this 5th day of September 1894.
FREDERIC PRINCE,
Agent for Applicant.
Improvements in Incandescent Gas Lighting.
I, HERRMANN FRIEDLANDER, of Royal Hotel, Blackfriars, London, Merchant,
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 relates to the manufacture of the bodies or frames placed over
gas burners which become incandescent by the heat from the lighted gas.
The incandescent bodies as now made are produced from various earths by
saturating an open-meshed textile fabric with the solution or emulsion of such earths,
and incinerating the fibre. They however present the defect that the composition
of the materials gives a peculiar greenish white colour and makes the light unsuit-
able for some purposes, and moreover the method of manufacture adopted makes
these articles extremely delicate, so that they readily break or become damaged and
hence unfit for use.
Incandescent bodies produced according to the present invention are free from
these defects. The light yielded where they are used has a yellow warm tint
of daylight, pleasing to the eye; and the method of manufacture is such as to
make them more durable and capable of greater resistance than those heretofore
known.
For producing these incandescent bodies according to the present invention a
mixture of the oxides of thorium, lanthanum and didymium is used. Suitable
proportions are as follows:-
Oxide of.thorium
"
99
„,. didymium
lanthanum
-
وو
This gives a white light with a slightly yellow tinge.
96-98 per cent.
1-2.. "
1-2
"
" . "
The proportions of the didymium causing the yellowness, must be small as this
substance causes a considerable colouration of the light. The proportions of
Janthanum may if desired be increased. Thorium oxide makes the article capable
of resistance and durable. Lanthanum oxide may however be wholly or in part
substituted therefor without sacrifice of that advantage. Thus 98 per cent. of
lanthanum oxide and 2 per cent. of didymium oxide may be employed in the manu-
facture. By increasing the proportion of didymnium oxide the colour of the light
is made more yellow. About 5 per cent. will probably be the limit of such
addition.
The manufacture of such bodies for incandescence from the oxides of thorium,
lanthanum and didymium, or of those of lanthanum and didymium alone is effected
as follows:-The materials are finely pulverised and mixed in the above indicated
proportions and then made into a dough or paste by a suitable cementitious material,
y liquid glue for instance. The dough or paste is forced out from'a press cylinder.
1.

page_text: in thread or threads, which is, or are, afterwards woven into a net, and from that
the tapering cap, like bodies are made which by suitable holders are fixed over the
flame of a gas burner.
By adding glycerine to the said dough or paste, it is kept elastic after it is pressed
out to shape, and will not readily become hard and brittle. The net-like structure
made as above is next dried and then burnt to remove the glue or other cement, and
this makes the threadlike material hard and rigid. To burn the net, cap, or article,
it is put on a mould corresponding to the shape required, consisting of platinum
wire, or other fireproof material, say porcelain, clay, or fire-clay; and the cap and
mould heated to such a degree as to entirely remove the lime or the like. The
material of the article is then hard and firm and can be handled for fixing on the
burner without falling to pieces.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed I declare that what I
claim is:-
An article capable of incandescence by heat, such as gas, consisting of a mixture
of thorium oxide, lanthanum oxide, and didymium oxide; or lanthanum oxide and
didymium oxide alone; which substances are made into a paste with cementitious
material pressed into the shape of threads, from which a network is made, the whole
being then burnt on a suitable mould all substantially as set forth.
Dated this 5th day of June 1895.
FREDERIC PRINCE,
37, Cursitor Street, Chancery Lane, London, Agent for Applicant.