Improvements in Appliances for Producing Light by Incandescence.
Year: 1890

page_text: Date of Application, 22nd Oct., 1890
Complete Specification Left, 22nd July, 1891-Accepted, 10th Oct., 1891
PROVISIONAL SPECIFICATION.
Improvements in Appliances for Producing Light by Incandescence.
I THOMAS HESKIN of 106 Waterloo Road, Ashton-on-Ribble in Preston in the
County of Lancaster Solicitor's Clerk do hereby declare the nature of this invention
to be as follows:-
These improvements relate to the method of producing light by heating to
incandescence by means of Bunsen or other gas burners magnesia or other
refractory earthy substances and of automatically supplying and renewing such
substances.
Hitherto the appliances for producing light by this method have consisted of a
mantle or hood formed of magnesia network. Owing to the delicate and fragile
nature of such appliances they have been liable to be fractured and rendered
useless. Moreover it has been found that the light-giving properties of these
appliances rapidly deteriorate and they have to be frequently renewed.
The principal feature of my invention consists in the preparation of a mixture of
certain chemical substances which when suitably applied to the flame of the burner
evolves a continuous supply of refractory earth.
The mixture referred to is prepared as follows:-I dissolve 1 part by weight of
chloride of magnesia in water and add thereto 2 parts of glycerine. I then gently
heat the mixture until it has attained the consistence of syrup after which I add a
sufficient quantity of magnesia to make it slightly pasty. I remark that the above
proportions may be varied within certain limits.
I now proceed to describe the method in which I apply the mixture for the
purpose of producing light by incandescence.
My appliance consists of a metallic cylinder (preferably of platinum) which is
fixed in the central airway of an Argand Bunsen burner and is filled with the
mixture prepared as before described. The external diameter of the cylinder is
about one fourth of an inch less than the interior diameter of the flame and extends
to a height of about two inches above the height of the flame. The exterior of
the cylinder is fitted with a number of short tubes each of about one sixteenth of
an inch in diameter and placed the same distance apart. Such tubes are composed
preferably of platinum foil and are fixed at right angles to the cylinder and com-
municate with its interior and project to such a distance as to almost but not actually
touch the flame of the burner.
When the burner is lighted the heat of the flame melts the mixture at the end of
each tube and decomposes it. During the decomposition the gaseous products of
the glycerine on being set free cause the mixture at the end of each tube to swell
out and immerse itself in the body of the flame where the decomposition is
completed, a residue of magnesia being left adhering to the end of each tube.
I remark that if the ends of the tubes actually touch the flame the decomposition
of the mixture takes place too rapidly and the magnesia is left in an extremely
ight and porous form which is not so well adapted for illuminating purposes as the
lenser form.
So long as the tubes remain in the same position with respect to the flame the
upply of magnesia will be continued until the whole of the mixture in the cylinder
exhausted. To prevent this continuous supply I block up the ends of the tubes
the interior of the cylinder by moving a slide simultaneously with the turning on
f the gas and so cut off the supply.
Instead of placing the cylinder in the central airway of the burner I sometimes
lace it above or below and have moveable platinum wires passing through the
ixture by means of small holes in the top and bottom of the cylinder so that when

page_text: '
such wires are drawn through the mixture they become covered with a coating of
it and on approaching the flame the mixture is decomposed as previously described
the residue of magnesia nevertheless adhering to each of the wires.
The acetate or any of the other salts of magnesia which are decomposed by heat.
may be substituted for or used in addition to the chloride in the preparation of the
mixture as may also any of the oxides or salts of the metals lanthanum, zirconium,
yttrium or thorium which are decomposed by heat.
Many of the organic acids and other organic chemical compounds which evolve
gases during decomposition by heat may be substituted for glycerine in preparing
the mixture but I prefer to use only such of these compounds as evolve carbonic
acid gas or other practically non-deleterious gas. Of these compounds oxalic acid
is the most suitable.
THOMAS HESKIN.
COMPLETE SPECIFICATION.
Improvements in Appliances for Producing Light by Incandescence.
I THOMAS HESKIN of 106 Waterloo Road Ashton-on-Ribble in Preston in the
County of Lancaster Solicitor's Clerk 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:-
These improvements relate to the method of producing light by heating to
incandescence by means of Bunsen or other gas burners magnesia or other
refractory earthy substances and of automatically supplying and renewing such
substances.
1
Hitherto the appliances for producing light by this method have consisted of a 2
mantle or hood of magnesia network. Owing to the delicate and fragile nature of
such appliances they have been liable at any time to be fractured and rendered
useless. Moreover it has been found that the light-giving properties of these
appliances rapidly deteriorate and they have to be frequently renewed.
The principal feature of my invention consists in the preparation of a mixture of
certain chemical substances which when suitably applied to the flame of the burner
evolves a continuous supply of refractory earth. The mixture referred to is
prepared as follows:-I dissolve one part by weight of chloride of magnesia in
water and add thereto two parts of glycerine. I then heat the mixture until it has
attained the consistency of syrup in which state it is suitable for application by
some of the means afterwards described but for application by other means also
described I prefer to add to the mixture at this stage of consistency about one
twelfth part its weight of magnesia and heat the mixture further until it has ceased
to froth and has attained a thick pasty condition.
I now proceed to describe the means by which I apply the mixture for the
purpose of producing light by incandescence previously remarking that the burner
I prefer to use is one giving a low short but hot flame about half an inch in
height.
T (Fig. 1) is a metallic or earthenware vessel about 4 inches in height and
2 inches in diameter extending to about 6 inches at the base or any other propor-
tionate size convenient for attachment to a Bunsen burner. The base B which is
fixed in or about of an inch above the central airway of the burner is about half
an inch less in diameter than that of the flame so as to allow a clear space for the
air to ascend. The base is fitted with a circle of small tubes h, h, h each tube being
of an inch in length and of an inch bore and placed about of an inch apart.
Such tubes are composed of thin platinum, nickel or silver and are fixed at right
angles to the base and almost but not actually touch the flame of the burner at a
point of an inch below its extreme height.
The vessel T is filled with the thick pasty mixture prepared as before described

page_text: which ultimately appears at the end of each of the tubes h, h, h in the form of a
bead. When the burner is lighted the heat of the flame decomposes the mixture
at the end of each tube. During the decomposition the gaseous products of the
glycerine on being set free cause the bead to swell out and immerse itself in the
body of the flame where the decomposition is completed, a residue of magnesia
being left adhering to the end of each tube generally in the form of a small cone.
Each cone being heated to incandescence emits a brilliant white light. I remark
that if the ends of the tubes actually touch the flame the decomposition of the
mixture takes place too rapidly and the magnesia is left in an extremely light
and porous form which is not so well adapted for illuminating purposes as the
denser form.
Instead of placing the reservoir or vessel T in the central airway of the burner
I sometimes place it above or below the burner (which latter may be a straight or
curved tube burner or any other form than an Argand) and draw wires of platinum,
nickel or silver through the mixture so as to cover them with a coating of it and
when such coated wires come into contact with the flame the coating is decom-
posed as previously described and tufts of magnesia are left adhering to the
wires.
The wires I prefer to use for this purpose do not exceed of an inch in thick-
ness and may be finer and of any length commensurate with the size of the burner.
The form of such wires may be modified in various ways to suit the various degrees
of consistency of the mixture with which they are to be coated. If the mixture is
of a syrupy consistency a straight wire is not suitable as the mixture with which it
is coated will become fluid when heated and run off the wire.
Fig. 2 shows the form of wire I use in such cases which is practically a chain of
small circles each circle being one eighth of an inch in diameter and of an inch
apart. Each of these circles holds within it a drop of the liquified mixture where
it is retained by its cohesive force. When a wire so charged is gradually brought
into contact with the flame of a tube burner the drops of mixture undergo further
concentration and ultimately decompose in manner previously described with
reference to the mixture in the tubes h, h, h, (Fig. 1) the result of such decomposi-
tion being identical in both cases.
Fig. 3 shows another wire 16 of an inch thick which is notched at distances
corresponding with the circles of the wire lastly described each notch retaining a
small portion of the mixture.
When the mixture is brought to a high degree of concentration or consistency
no special form of wire is requisite in order to retain the mixture during the
process of decomposition, a plain straight or curved wire being used. Sometimes
use two wires in juxtaposition or a single wire with a longitudinal groove or slit
cut into it so that the mixture fills up the groove slit or interstice between the two
wires the other parts of the wires being freed from mixture.
Fig. 4 shows a wire 1 of an inch thick with small grooves or slits cut into it
cross wise at distances of 1 of an inch each groove or slit being filled with the
mixture to the exclusion of the rest of the wire so that after decomposition the
magnesia adheres to the wire in isolated tufts.
When the mixture of a high consistency is allowed to cool after its preparation it
sets into a hard brittle mass and in this condition it may be reduced to a fine
powder by crushing and grinding. In this powdery condition it readily adheres to
the wires drawn through it and I sometimes substitute it for the pasty mixture.
The vessel holding the mixture in this powdery state is placed below the burner and
kept free from heat and moisture. In all other cases where wires are coated with
mixture of a high degree of consistency the vessel holding the latter is placed
above the burner so that the heat of the flame may-melt it but when using mixture
in a soft or syrupy state the vessel is placed below. Such vessel need not be of the
shape or form shown in Fig. 1 when used in conjunction with the wires but may be
of any other convenient size or form.
I now proceed to indicate how the magnesia is renewed from time to time, with

page_text: When the burner is
first lighted the bead of mixture at the end of the tubes h, h, h, is decomposed as
previously described but the flame is unable to decompose the remaining portion
of mixture in the tube as the distance is too great. When the appliance is not in use
the mixture in the tube being deliquescent absorbs moisture from the atmosphere
and forms another bead at the end of each tube which evolves a further supply of
magnesia when decomposed.
reference to the apparatus or appliance shown in Figure 1.
I remark that the acetate or any other salts of magnesia which are decomposed
by heat may be substituted for the chloride as may also any of the salts of the
metals lanthanum zirconium yttrium or thorium which are decomposed by heat.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The preparation as herein described of a mixture of glycerine with any salt or
salts of magnesia and treated as set forth for the purpose specified.
2. The appliance shown in Figure 1 consisting of a reservoir or vessel with tubes
substantially as herein described and for the purpose set forth.
3. The use as herein specified of wires coated with the mixture prepared as
described for the purpose set forth.
Dated this 21st day of July 1891.
THUS. HESKIN,
Applicant.