Improvements in Means for Incandescent Lighting.
Year: 1896

page_text: Date of Application, 24th Dec., 1896-Accepted, 18th Dec., 1897
COMPLETE SPECIFICATION.
Improvements in Means for Incandescent Lighting.
I, CHARLES COLAS, of 3 Rue de la Cathédrale, Rheims in the Department of Marne
in the Republic of France, 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; reference being had to the
accompanying drawings and to the letters marked thereon that is to say
Gas lighting by incandescence is at present effected by the employment of a
frangible inantle heated to a high temperature and such mantles as is well known are
most difficult to manufacture and those who use them daily know by experience that
they are not only very expensive but also and especially that their extreme fragility
makes it necessary that they should be frequently renewed at considerable expense
and generally with the obligation of employing a gas-fitter to place them in position
and the time and tediousness which this work involves, unhappily too often repeated,
makes it an expensive and almost impracticable undertaking.
A mantle of this character is so light and fragile that a simple current of air will
sometimes render it useless and this trouble is also often brought about by the
explosion occasioned in lighting indeed even by the ascensional force of the gas
issuing from the burner.
The desirability of dispensing with the mantle or at least of producing a solid
mantle or its equivalent has long been recognised and the object of the present
invention is to attain that end.
In the course of numerous experiments I have absolutely proved that the employ-
ment of kaolin (otherwise known as porcelain paste) associated in suitable proportions
with certain salts or metallic oxides hereinafter described gives results which can be
put to practical use.
I have also discovered that argillaceous (clayish) materials in general such as
plastic clay, refractory earths, alkaline silicates, soda, lime, potash, cement or sulphate
of lime,, associated with these various salts or metallic oxides give by refrangibility
or otherwise a colour or brilliance applicable to lighting.
I have also remarked the cohesion which the association of kaolin and the other
materials herein before mentioned gives to the pulverulent molecules of the salts
and oxides.
In carrying the invention into effect the material employed may consist of a
mixture of oxide of thorium (or other metallic oxides which are capable of being
rendered incandescent when heated to a high temperature and such for example
as zirconium, lithium, magnesium, zinc.) of kaolin or of plastic or non-plastic clay of
pyro-phyllites, or of allophanes with or without enamel paste as a binding
material.
The following formule give examples of the ingredients, and their proportions
which have been found to answer well in practice, but it will be understood that they

page_text: are only given as example; as it will be evident that the proportions can be further
more or less varied according to circumstances without departing from the spirit of
the present invention.
Tho kaolin is first cleared of all impurities and reduced to impalpable powder; it is
then combined in suitable proportions such as those given above with the other
ingredients named and to these materials which must be thoroughly mixed together
in a dry state is added a sufficient quantity of water to produce a liquid of creamy
consistency.
To this solution is then added a quantity equal to 8 per cent of powdered gum
arabic.
The mixture is then further stirred until the gum is entirely dissolved which
generally occupies a period of about six hours.
The core or base of the solid mantle or device intended to produce incandescence
and which is a suitable fabric of the ordinary character is made to the form required
to produce the shape desired to be given to the finished object; for example the
shape of the finished object may be that given in the drawing in which the solid
mantle or device a is of tulip shape and provided with a nib or stud a which is.
received into a holder carried by the burner.
This fabric-base, or foundation, is then steeped or repeatedly dipped in the creamy
solution above given for several minutes, that is to say until it has absorbed a
sufficient quantity thereof.

page_text: The article is then dried or allowed to dry at a temperature not exceeding
20 to 25 degrees Centigrade, care being taken to observe the conditions usual in the
manufacture of porcelain ware.
Immediately that the articles have sufficiently set to enable them to be transported,
they are placed in a saggar and conveyed to a muffle or oven, and baked or hard
fired and subsequently gradually cooled in the same manner as that employed in the
production of porcelain goods.
During my experiments with the solid mantles constructed according to the
present invention I made comparative trials between the different incandescent
burners with ordinary frangible mantles and my own burner with a solid mantle or
tulip of porcelain a the form of which can be more or less varied according to
requirements, and I demonstrated the incontestable superiority from all points of
view of my invention.
The device possesses the following advantages, namely, perfect incandescence and
solidity, absolute simplicity of manufacture, non-liability to deformation as in the
ordinary frangible mantle, non-liability to unjury under the action of heat, ease with
which it may be placed in position upon the burner and the chimney mounted in the
gallery without skilled aid, moderate price, and great durability.
Instead of producing the solid mantle in the manner herein before described the
composition may be pressed or moulded to the desired form.
It will be obvious that the.device may be heated to incandescence by any suitable
medium.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is :-
1. A device adapted to be heated to incandescence composed of a suitable fabrio
steeped in a solution composed of the herin before named ingredients combined in or
about the proportions stated and subsequently dried and baked or fired substantially
as herein shown and described and for the purpose stated.
2. The employment of kaolin and plastic clay alkaline silicates infusible and
fusible salts cements plaster associated with the salts or metallic oxides and even
with foreign bodies in or in about the proportions stated with the object of producing
incandescent lighting by gas or other suitable medium substantially as herein before
described.
3. The manufacture of a material which may be brought to incandescence for
lighting constituted by the mixing of kaolin, oxide of thorium or other metallio
oxides which are capable of being heated to incandescence in combination with clay
and sometimes enamel substantially as herein described.
4. An incandescent object composed of the ingredients nained substantially as
herein described.
Dahi with dan
1000
WHITE AND WOODINGTON,
27 Southampton Bldgs. London. Agents.