Year: 1896

page_text: Date of Application, 1st Dec., 1896-Accepted, 13th Feb., 1897
A communication from DE RUYTER HOLLINS, Gentleman, of No. 62 West 55th
Street, New York, United States of America.
I, ALFRED JULIUS BOULT of 111 Hatton Garden, in the County of Middlesex,
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 relates to improvements in a composition of incandescent material
from which incandescent devices or hoods are made for use in connection with gas.
The invention relates to a composition for the manufacture of incandescent devices,
or hoods of that class which are made entirely of mineral substance and without a
cotton stocking or the like.
Heretofore such materials consisted simply of the refractory earthy oxides such
as calcium oxide, magnesium oxide, zirconia, thoria, etc., but such materials are alone
not well adapted for the purpose although they are so-called incandescent oxides.
These incandescent oxides are capable of becoming nicely incandescent, but they
lack the quality of radiating the light, they are brilliant to look at, but at a small
distance from the incandescent body made of such material there is not sufficient
light because there is no diffusion of the light when such an incandescent material
alone is employed.
Further compositions have been suggested for incandescent material regardless
of the chemical properties of the single substances or of the compositions owing
to the lack of experience in and knowledge of the subject.
In
A composition in order to constitute a perfect incandescent material must possess
above all four principal qualities which are imparted by suitable substances.
order to insure incandescence the composition must contain one of the incandescent
materials; in order to insure durability the composition must contain undestructable
and unvolatisable body; in order to insure the radiation of the light the composi-
tion must contain a substance or substances capable of diffusing the light and in
order to concentrate the heat of the gas within the incandescent device the
composition must contain heavy materials so that the manufactured incandescent
device will have a good weight in proportion to its size. The above is the result
of exhaustive scientific research and careful experimenting and it is claimed that
these requisites for a perfect incandescent gas light have first been employed in this
composition.
This novel composition for incandescent material consist of magnesium oxide,
powdered porcelain or the components thereof, powdered asbestos, sulphate of
chromiumn, lime, sulphate of barium, thoria and zirconia. In some instances minium
is used in place of sulphate of barium or a mixture of both. The magnesium is the
so-called incandescent material, the porcelain and the powdered asbestos give
durability; the sulphate of chromium and the oxide of calcium give the diffusion
of the light; the sulphate of barium or minium give the desired weight to the
incandescent device and the thoria or zirconia help to diffuse the light and give a
desirable and agreeable white or yellowish light. The proportions in which the
components are preferably employed are 15 parts of magnesium oxide, 7 parts of
porcelain body, 2 parts of powdered asbestos, 1-5 parts of sulphate of chromium,

page_text: 1 part of lime, 3 to 5 parts of sulphate of barium or minium or a mixture thereof
and 1.5 parts of thoria of zirconia or a mixture thereof. These proportions are
varied for the different kinds of illuminating gas in connection with which they are
used. Pure thoria gives in the above composition a white light, pure zirconia gives
a mellow, golden yellowish light and by employing both in various proportions any
tint of light between pure white and golden yellow can be obtained. The sulphate
of chromium is employed because oxide of chromium is disagreeable to the eye and
hurts the same, while the sulphate of chromium does not hurt the eye and still
gives the desirable quality of diffusion and intensity to the light.
The above materials are mixed together preferably in form of dry powder, then
the mixture is rubbed into an organic binder such as sugar solution, a solution of
gun cotton or the like in order to obtain a plastic mass which permits of shaping
the incandescent devices in the usual way. The incandescents are then dried and
baked in suitable ovens in the usual manner when they will be ready for use.
Having now particularly described and ascertained the nature of this inven-
tion as communicated to me by my foreign correspondent and in what manner
the same is to be performed, it is declared that what is claimed is:
1. A composition for incandescent material consisting of magnesium oxide,
porcelain body, powdered asbestos, sulphate of chromium, oxide of calcium, sulphate
of barium and minium and thoria and zirconia, substantially in the proportions
specified.
Dated this 1st day of December 1896
BOULT & WADE,
Agents for the Applicant.