IMPROVEMENTS IN OR RELATING TO ARTIFICIAL ILLUMINATION, AND IN APPARATUS CONNECTED THEREWITH
Year: 1880

page_text: LETTERS PATENT to Joseph John William Watson, of St. Marychurch, South
Devon, Gentleman, for an Invention of "IMPROVEMENTS IN OR RELATING
TO ARTIFICIAL ILLUMINATION, AND IN APPARATUS CONNECTED THEREWITH."
PROVISIONAL SPECIFICATION left by the said Joseph John William
Watson at the Office of the Commissioners of Patents on the 3rd June
1880.
JOSEPH JOHN WILLIAM WATSON, of St. Marychurch, South Devon, Gentleman.
"IMPROVEMENTS IN OR RELATING TO ARTIFICIAL ILLUMINATION, AND IN APPARATUS
CONNECTED THEREWITH."
My Invention of improvements in or relating to artificial illumination has
reference to the employment of electricity in connection with flames arising from
combustion as used for lighting purposes generally, the object to attain being
increased luminous power in the said flames. The Invention is especially appli-
cable to the flames proceeding from any compound combustibles of the class of
hydro-carbons, whether existing already as permanent gas or in a solid or liquid
state previously to being raised by means of a wick or otherwise into a gas or
vapor whilst undergoing combustion, but I may also employ electricity in con-
nection with flames arising out of the combustion of simple substances, such, for
example, as carbon or hydrogen and the like, or of such combined substances as
may number among their elements more than merely hydrogen and carbon (to
wit), the large family of the alcohols, which contain hydrogen as well as other
elements.
"
In carrying out my Invention I employ burners which will admit of the
illuminant it is intended to employ being converted into a flame most suitable for
the purpose, and preferably of a "fish tail" or batswing form" if gas be used
(whether such gas be of the ordinary kind, or "air gas" made from petroleum, or
gasoline gas," or "benzoline vapor" indifferently), or of a fan shape if obtained
by burning liquid petroleum or vegetable or animal oils and fats. I then introduce
the electricity into the body of such flame by means of "electrodes," which may be
made either of platina, copper, or wires of any other metal not affected by the
"

page_text: flame, or may consist of small rods or pencils made of graphite or plumbago, the
points of these electrodes being placed in the direction of the longer axis of
the flame, and at such striking distances apart as, having due regard to the
conducting power of the flame, the discharge may take place with greatest effect,
and embrace in its action the largest area lying within the flame; or I constitute
the flames themselves the electrodes, that is to say, I place two or more flames of
the most convenient shape and size in juxtaposition, and in a manner so that when
exposed to the electric discharge they shall serve as the path for the same coalescing
whilst burning, but otherwise insulated as to the jets or burners from which they
arise, such jets or burners being grouped if consisting of more than two, and in
any case made the respective terminals by which the electricity may enter and
leave the flames. In this manner it may be considered that any single flame or
group of flames acts (as the case may be, according to its electrical connections) as
the positive or negative pole, the "anode," or "cathode" relatively to its fellow
flame or group of flames. "Bats' wings," "fish tails," "union jets," fan shaped and
other forms of flame, may thus also be converted into an electrode, but it is
preferred to employ special forms, wherein by the overlapping of edges and by
playing into one another when under the electrical action perfectly solid flames
can be constructed and perfect combustion ensured.
In order to obtain the required electricity I may either employ electro-static
machines of the inductive class, or induced currents derived from coils excited in
various ways, or magneto electric machines or dynamo electric machines specially
arranged, so that the coils shall form a part of the said machines or otherwise.
For example, I may make use of the current derived from a suitable helix or
helixes excited by a primary electro magnetic coil, excited in turn by the current
obtained either from a dynamo-electric engine arranged to admit of subdivision of
its energy, or from a given number of cells of the most convenient form of galvanic
battery that the circumstances of the application as to locality, &c., may suggest
and admit of.
In the preparation and manufacture of these "inductoria" or electro magneto
electric coils I propose to employ porous porcelain saturated with paraffin for the
substance of which the discs are to be made, and also to otherwise modify the
apparatus so as to obtain increased cheapness, as well as durability, better
insulation, and other advantages.
In the distribution of my primary existing current from the dynamo-electric
machine or battery (if cells are used) to the "inductoria" I prefer to lay my
positive main in glazed earthenware pipes, stretching the wire through the centre
of a porcelain or earthenware diaphragm placed in each joint of the pipe, so as to
leave a clear air space always round the main, which should be of tapering section
obtained in the most convenient manner, and give out at regulated distances
branches to the "inductoria," the section of such branch wires being calculated to
offer definite resistances in order that the supply of current may be proportional
to the strength of the coils. The largest section of the main and the smallest
supply wires to the inductoria will consequently be always collocated at the
machine ends of the circuit. The negative main may be an iron rod offering the
same resistance as the thickest section of the positive main, but laid in the earth
contiguous to the pipe carrying the positive main without any kind of insulation,
the object being to take advantage also of the earth's conductivity.
The insulation of the secondary wires from the "inductoria" may be effected in
a similar manner, using wooden, vulcanite, or porcelain tubes of larger section than
the wires, and each wire having its separate trunk or case to itself.
The "inductoria" distributed along the line may be provided with self acting
electro magnetic worked switches, by which rheostatic arrangements may equalize
the amount of current flowing into the other lamps when any group of lamps are
extinguished. Similar contrivances may also be attached to individual burners
and worked by hand, and the apparatus may be so arranged that the main cock
for the supply of the gas in any group of burners shall, in the same operation, turn

page_text: on the electric current, set going the "inductorium" or "inductoria," and light up
the lamps without any extraneous assistance. For the measurement of the
electricity supplied to consumers I propose to use the existing gas meters, applying
to them simply an extra set of dials worked by the gas when thrown into gear by
an electric current exciting an electro magnet in the usual manner, and which
current will be the same as that coming from the dynamo electric engines or
batteries, and only to be utilized in the inductorium after working through the
meter..
This arrangement will admit of the gas being burnt without the application of
the electricity if desired, and without also in that case disturbing the ordinary
working of the meter, which will thus exhibit to the inspector the quantity of
gas burnt with, as well as the quantity of gas burnt without, the use of the
current.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Joseph John William Watson in the Great Seal Patent Office on the
3rd December 1880.
[
JOSEPH JOHN WILLIAM WATSON, of Saint Marychurch, South Devon, Gentleman.
IMPROVEMENTS IN OR RELATING TO ARTIFICIAL ILLUMINATION, AND IN APPARATUS
CONNECTED THEREWITH."
My said Invention has for its object securing increased luminous power by the
use of electricity in the flames arising from combustion as used for lighting purposes
generally. The Invention is specially applicable to the flames proceeding from any
compound combustibles of the class of hydro-carbons, whether existing already as
permanent gas or in a solid or liquid state previously to being converted into a gas
or vapour by means of a wick or otherwise (as, for instance, in using fats and
their derivatives, stearine and stearic acid, margarine and margaric acid, palm oil
and its constituents, palmitin and palmitic acid, cocoa nut oil, cocinin and cocinic
acid, spermaceti wax, paraffin, animal and vegetable oils of all kinds, all the so
called mineral oils, the oil of turpentine or camphine, coal tar, naphtha, benzole,
or, in fact, any of the substances used in the shape of candles or fluids for burning
of the hydro carbon class, and which may be thus converted through the agency
of a wick or otherwise into a gas or vapor whilst undergoing combustion), but I
may also employ electricity in connexion with flames proceeding from simple
substances, as, for example, hydrogen or carbon burnt to carbonic oxide, or those
arising from such compound substances as may number among their elements more
than merely hydrogen and carbon (to wit, those which contain in addition oxygen,
and even other elements), as in the large family of alcohols.
In carrying out my said Invention I employ burners which will admit of the
illuminant it is intended to employ being converted into a flame most suitable for
the purpose, and preferably, if coal gas be used, of the description of jets known as
"fish tails
and "bats' wings," arranged so that their flaines may intersect at
various angles, the object to be attained being the generation of a solid flame
surrounded on as many sides as possible by the air; thus three flames may cross
each other at angles of one hundred and twenty degrees; or they may form in
plan an equilateral triangle, having a hollow in the centre, the flame itself being
solid and continuous, as in an "argand," or four flames may be arranged to coalesce
by their edges meeting in the centre; or I may use any arrangement of the jets
commonly in use to produce a flame of a concrete description, and the same is
applicable not only for use with coal gas of the ordinary kind, but when using
oil gas, resin gas, water gas, wood gas, peat gas, gas from other vegetable residua,
from coal tar, from petroleum or napthalized atmospheric air, gasoline or benzoline
vapor, or any other combustible used in the forin of a permanent gas. If the
combustible used be of a solid or liquid form then I arrange the disposition of the
wicks so as to arrive at the same results so far as regards the flames to which
they contribute; and such being the arrangements concerning the flames to which
an electric current is to be applied my modes of effecting this application are as
follows, it being preinised that the most thorough dissociation of the carbon from
the hydrogen forms the object, and that the current may therefore be applied to
the flames either to act electrolytically in an independent passage through them or
in a path provided for it, but offering sufficient electrical resistance to secure by its
incandescence the required dissociation as an effect either of heat and electricity
combined or of heat alone:-
For affecting flames electrolytically I lead into them a powerful induced current
derived from the electro magnetic coil machines known as "inductoria," or from
magneto electric machines, or from electro static machines of the inductive class,

page_text: "
or from dynamo-electric machines arranged with supplementary inductive coils so
as to secure high tension or density at their poles, resulting in disruptive
discharges when properly arranged. The electrodes for leading in these induced
currents, howsoever obtained, may be made of any convenient conducting substance,
but preferably they should be of platina or platinized-copper. The points of the
electrodes should be disposed in the flames so that the discharge shall take place
through the greatest breadth of the same, thereby affecting the largest area of
combustion, but passing primarily into the non luminous or dark parts of such
flames (where merely heated gas exists), and where dissociation of the carbon and
hydrogen have not yet commenced; thus in a "bat's wing" or "fish tail" flame
simple the induced current would discharge along its longer axis, and at such
striking distance as that, having due regard to the conducting power of the flame,
the discharge would embrace in its action the largest area of action with the
highest effect. I also constitute the flames themselves electrodes, that is to say, I
place two or more flames in juxtaposition, leading the poles of the induction coil or
other source of the induced current into them as aforesaid, but arranged so that
the line of discharge shall take place through the points at which such contiguous
flames shall intersect or coalesce. In this manner it may be considered that any
single flame or group of flames acts (as the case may be, according to the nature of
its connexion with the source of the current) as the positive or negative pole, or, in
other words, the "anode or "cathode" relatively to the fellow flame or group of
flames, which permit of the circuit being completed. "Bats' wings," "fishtails,"
or "fanshaped" flames, or even those formed by "union" and other "pipe shaped
jets may thus serve, so to speak, as dectrodes, but I prefer to employ the transverse
discharge between intersecting flames, as first herein before described.
"
23.
"
In exciting the magneto electric or induction coils I do not confine myself to
any one special source of electricity, as I may use either the ordinary galvanic
battery of the various known forms at present in use, or any other suitable
galvanic battery, or I may employ the current obtained from the various forms of
imagneto electric machine and dynamo electric engines.
In the preparation of the electro magneto electric-coils, or "inductoria," I
employ porous porcelain plates, unglazed and saturated with paraffin, to replace the
dividing discs (usually now formed of vulcanite); I also use glazed porcelain or
earthenware to form the base plates and receptacles for the condenser, so as to
obtain increased cheapness, better insulation, and greater durability, as well as
other advantages.
In order to employ electricity and high temperature simultaneously to promote
the desired dissociation of the chemical elements present in a flame I employ a
second method, which consists in setting up the "electric arc," whether generated
between the ordinary carbon points or between electrodes of other good conducting
substances, and for this purpose I introduce the electrodes into any suitable form
of flame, governing their consumption and the maintenance of their position, both
as regards one another and their focality in relation to the flame or flames, by any
methods most convenient, it also remaining at option to employ such electrodes in
a vertical, horizontal, or any other position. Thus, if intermitting currents are
employed (such as are now obtained from many of the magneto and dynamo
electric engines in public use) it may be convenient to form the gas focus by jets
thrown horizontally, or at an angle between a pair of vertical or inclined parallel
electrodes, descending or ascending by a revolving screw or other elevator from
above or below, the place of the gas flames remaining a fixed point, or if the
current be direct acting in one direction only the electrodes may be held
horizontally or inclined to each other, with a differential action allowing for their
unequal action, and at the same time maintaining their focality a fixed point as
regards the gas jets. In all cases the points of the electrodes should remain
constantly immersed in the flame, so that the arc may be always generated solely
within it, and the flame thus, be exposed to the full modifying influence of the
current, whether electrically as promoting its decomposition, or as arising out of

page_text: the great elevation in its temperature owing to the spread of the incandescence
taking place between the poles.
A further method of applying electricity to a flame according to my said
Invention, has for its object effecting the dissociation of the products undergoing
combustion in a flame mainly by the secondary result of the high temperature
to be obtained by high electrical resistance. For this purpose I employ such
materials as shall be able to conduct an electric current with much resistance to
its passage, such as platinum and the platinoid metals, palladium, iridium, rhodium,
and the like, carbon in the form of graphite or carbonaceous nonfusible compounds
combined with such nonfusible substances as asbestos, steatite, lime, magnesia, and
the like, or without them, and used alone. I prefer, however, to use platina wire,
or foil coiled upon a spool of "asbestos," or a cylinder of magnesia, or lime, or
tale, or a coil may be formed and the interior furnished with a core of these
substances.
And in order that my said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose shall refer
to the several Figures on the annexed Sheet of Drawings.
Figures 1 to 6 of the accompanying Drawings represent the arrangements of jets
which I prefer in order to produce flames best adapted to the different methods of
electrolyzing them. Thus, the arrangement shewn at Figures 5 and 6, composed
simply by the blending of two "fishtail," or "bats wing," or even round jets, is the
best adapted for giving good results with the intermittent current produced from
electro-magneto coils and "inductoria;" the electrodes, of whatever substance they
may be formed, being arranged at convenient striking distances within the body of
the flames, and coincident with the axes of the same, along which paths the
discharge will be found to take place. Figures 1 and 4 shew in plan prismatic and
pyramidal flames well adapted for use with the electric are proper, or for being
subject to the incandescence derived from a coil with or without a spool.
Figure 1 a three sided prism is obtained by the use of three "fishtail" or
"batswing" burners, inclined inwards to produce a "cocked-hat" flame, the apex
of which is shewn by the dark shading in the centre of the triangle; in Figure 4 a
quadrilateral prismatic, but also pyramidal, flame is obtained by the union of four
"fish tail" or "batswing" burners, all inclined inwards and directing their separate
flames to form a compound one with a square apex, indicated by the dark shading
in the centre of the quadrilateral.
In
"
Figures 2 and 3 exhibit in plan the paths of three and four flames arranged to
cut each other at a central point, the burners being of the "batswing" or fishtail'
type, this description of compound flame is well adapted for using with the
incandescent coils and spools.
In the above mentioned Figures the burners are indicated by the letters
A, B, C, D, and the paths of their flames by the letters a, b, c, d.
Figures 7 to 14 shew various forms of resistance coils combined with infusible
spools for setting up incandescence within a flame; Figure 7 shows a simple right
to left coil of stout platina wire carried over in the form of an arch, the spool being
formed of asbestos; Figures 8 and 9 are illustrations of vertical coils, the former of
stout platina wire and the latter of stout platina foil, wound the first upon spool of
asbestos, and the second on a cylinder of magnesia or lime. From the circumstance
of the wire or foil at the terminal of the coil passing down through the axis of the
same, where it becomes thoroughly insulated by the interposition of the infusible
body, these coils form half "solenoids." When solid these spools may be formed
in half cylinders divided longitudinally with a groove to receive the wire, or they
may be perforated with an axial bore, as may prove most convenient in manu-
facture. Figure 12 shows a double bee hive arrangement of the coil with an
asbestos core; Figure 14 is a conical or "pine apple" form without any core;
Figure 13 is a whole "solenoid" ready to receive either an asbestos or solid core
of lime, magnesia, and the like, as the case may be, and is adapted to wide flat
flames; Figure 10 is a simple coil from left to right wound on a solid spool, which

page_text: may be formed of carbon or the like; Figure 11 shews a naked spool with the
connecting wires used as such, and may be formed of any conducting compound
offering sufficiently high resistance to become incandescent during its passage.
In all these illustrations of coils and insulating spools made of refractory
substances the arrows show the direction of the currents, but it will be understood
that these may be alternately reversed with machines generating alternating
currents. The terminal conductors in each of the Figures are assumed to be of
stout copper wire and are lettered E, E¹.
Figures 15 and 16 illustrate in plan the combined arrangement of the coils and
gas jets, the former being omitted from the Drawings; Figure 15 shows an
arrangement of the conductors of the current within the gas supply, Figuro 16,
the reverse.
In each case the conductors are lettered E, E'. The insulating
material I and the gas jets are lettered A, B, D; G being the gas supply, which
may form an annular or upright pipe according as one or the other arrangement
is adopted. The illustrations of the coils show the terminals close together or wide
apart to suit one or other of these arrangements; but it is evident that any modi-
fications of this relationship between the supply of gas and electricity are
admissible, and may be used in carrying out my said Invention.
Where it is determined to set up the "electric arc" proper within a gas flaine
I prefer to employ a lamp of the peculiar construction represented in Figure 17 of
the Drawings, but lamps of other constructions may be used if desired. The
peculiar feature of the improved lamp consists in the mode of maintaining auto-
matically the focus (in a fixed position) of the carbon points relatively to the flame.
A is a base or stand from which rise two hollow standards or pipes S, S¹, which
are made of glass. These columns are surmounted by curved hollow arms or horns
y, y, carrying a hollow ring y, y, out of which any number and description of
gas jets may issue, throwing their flames into the focus indicated by the reversed
arrows. From the standards S, S¹, a circular platform 1 extends horizontally
supported by the brass rings G, G¹. This platform is perforated by a central
aperture 2 and two lateral apertures 3, 3, the uses of which will be hereinafter
described. Above this platform are superposed two horizontal brass armis 4, 4, each
carrying a small grooved roller or pulley, marked respectively L and L'. The
circular platform 1 should be made strong, it having to carry in its centre an
electro magnet D, through the hollow core of which passes a brass rod n³, carrying
at its upper end a round block of "steatite" porcelain or any other refractory non-
conducting substance c. The angles of this block are bevelled off and grooved like
the pulleys L, L. The brass rod which supports the block and passes through
the electro magnet carries at its lower extremity an armature or keeper E, placed
within the attractive distance of the magnet when this is excited by the current,
but from coming into contact with which it is prevented by a spiral spring coiled
upon it; in the space between the magnet and the keeper P is a horizontal bar or
plate carrying two short brass standards O, O', attached to hinged sockets intended
to receive the lower ends of the carbon electrodes X, X'. This platform P is con-
nected with a vertical rod t passing down through a stuffing box in the lid of the
cylinder B, and thence into a tube or stand pipe 5, which it fits at its lower
extremity by a solid plunger 6, thus converting it into a piston. Within the
cylinder B is a spiral spring 7, which presses on a dise or piston 8 provided with
suitable packing, admitting of its rising and falling with the stand pipe stationary
in the centre of it. The bottom of the stand pipe is perforated with a small hole
at 9, admitting a measured flow of liquid to pass into it below the plunger 6 when
under pressure from the annular piston 8 actuated by the spring 7, the mechanical
force of which is equal to raising at a measured rate the rod t, the platform P, and
the electrodes X, X₁. The increasing weight of the column of liquid in the stand
pipe is compensated by the decreasing weight of the carbon electrodes as they
consume away. The piston within the cylinder B besides being attached to the
spiral spring 7 has a rack 10 worked by a pinion wheel 11, by which it can be
drawn up against the action of the spring 7. A conical rod 12 fits the aperture 9

page_text: by which the liquid enters the stand pipe 5, and by withdrawing this when the
piston is elevated the liquid leaves the stand pipe freely and the platform P
sinks.
In order to put this lamp to work the electrodes are arranged in the sockets on
the platform P, having been previously inserted through the grooves in the
pulleys L, L', and the insulating block c. By means of a key at the pinion 11 is
actuated, thereby raising the rack and with it the piston 8, which is thus wound to
the upper end of the cylinder, the liquid in the upright tube 5 carrying the small
piston 6, and rod t folding back beneath it (that is to say beneath the large piston 8)
to again occupy the bottom of the reservoir, and become subject to the pressure of
the spring 7 through the medium of the piston 8. The current of electricity being
then permitted to pass, the gas also being simultaneously turned on, the electro
magnet attracts the keeper E, and this in turn pushing up the rod n¹ separates the
points of the inclined carbons X, X¹, and determines the presence of the "electric
arc," within the gas flame. The conical ended rod 12 within the cylinder or elevator
being then withdrawn the liquid will enter the stand pipe, and the platform P will
begin to rise and push forward the electrodes with a regulated speed as they
gradually consume away, and in this manner the " arc "will always be maintained
so long as there are any carbons left at a fixed point within the flames from the
gas jets. The arms carrying the pulleys L, L, are to be made of brass or other.
metal springs, so that the pulleys or rollers may rise or fall according as the block c
is elevated or depressed, and always with a certain amount of pressure, on the
electrodes in order to ensure good contact, the electric current entering and leaving
the lamp through the said pulleys. The inverted arrows show that this lamp is to
be used with an alternating current.
The fluid used to work the elevator may be oil, mercury, water, or the like; but
on account of its nonsusceptibility to evaporation and cold, I prefer to use glycerine
within the cylinder B.
In the distribution of the current of electricity, whether to be used for primarily
exciting coils in "inductoria," or to be applied direct, and from whatever source it.
may be derived, I prefer to lay my positive main (if the current be a direct
one, and both mains if of an alternating description) in glazed earthenware pipes,
stretching the wire through the centre of a porcelain or earthenware diaphragm,
placed in each joint of the pipe so as to leave a clear air space always round the
"main," which should be of tapering section obtained in the most convenient
manner, and should give out branches from it at regulated distances, either to the
'inductoria," or the direct applications of the current in lamps and the like, such
branch wires being calculated to offer definite resistances, in order that the supply of
current may be proportional to the strength of the coils or the number of lamps in
circuit or other conditions. The largest section of the main and the smallest supply
wires to the "inductoria" lamps and the like will consequently always be collocated
at the machine ends of the circuit. The negative "main" (where direct currents
are used) may be an iron rod, offering the same resistance as the thickest section
of the positive main, but laid without any protection or insulation in the earth
contiguous to the pipe carrying the positive "main," the object being to take
advantage also of the earth's conductivity. Where "inductoria are used the
secondary wires may be insulated upon a similar plan to that adopted for the
"mains," using wooden, vulcanite, or porcelain tubes of larger section than the
wires, and each wire having its separate trunk or case to itself.
"
The "inductoria" distributed along the line as well as the lamp groups may be
provided with self acting electro magnetic worked switches, by which rheostatic
arrangements may equalize the amount of current flowing into the other lamps
when any group of lamps are extinguished; similar contrivances may also be
attached to individual burners and be worked by hand. The main cock supplying
the gas in any group of burners may also be made part of an electric switch, so
that from the current appearing simultaneously with the gas the latter may be
ignited without further intervention. .

page_text: In order to indicate when the electricity is used in connection with the gas
supplied to consumers, I utilize the existing gas meters in the following manner, so as
to adapt them both for noting the consumption of gas and the presence of the
electric current:-For this purpose I apply to the existing gas meters an extra
system of dials worked by the gas when thrown into gear by an electro magnet,
which shall arrest the ordinary dials and permit only the supplementary dials to
come into action.
The current exciting the electro magnet is the same as that circulating in the
"mains" and arising from the dymano electric engine or otherwise, and which shall
only be utilized after passing through the said electric magnet. This arrangement
will admit of the gas being burnt if desired without the application of the electricity,
and without in that case disturbing the ordinary working of the meter.
The gas
burnt with the use of the electric current will thus be exhibited to the inspector,
who will apply to it the tariff which may be fixed upon for the increased intensity'
of the illuminating power.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original,
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is,-
First. The application of a current of electricity, of whatever derivation and
however applied, to increase the illuminating power of flames, whether obtained
from burning gas or other combustibles, substantially as hereinbefore described.
Second. The use of porous porcelain, unglazed and saturated with paraffin, to
form the dividing diaphragms in the construction of "inductoria," substantially as
hereinbefore described.
Third. The mode of insulation by means of diaphragms and pipes of non-
conducting materials of the mains and branch wires or conductors, substantially as
herein before described.
In witness whereof, I, the said Joseph John William Watson, have to this my
Specification set my hand and seal, the Twenty seventh day of November,
One thousand eight hundred and eighty.
JOSEPH J. W. WATSON. (L.S.)