CERTAIN IMPROVEMENTS IN APPARATUS FOR THE PRODUCTION OF LIGHT, FROM ELECTRICITY
Year: 1848

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME I FENNELL
ALLMAN of No. 18 Charles Street Saint James's Square in the County of
Middlesex Consulting Engineer send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria by Her Letters.
Patent under the Great Seal of Great Britain bearing date at Westminster
the Twenty-eighth day of September One.thousand eight hundred and forty-
eight in the twelfth year of the reign of Her said Majesty did give and
grant unto me the said Fennell Allman, my exors admors and assigns Her
especial license full power sole. privilege. and authority that I the said
Fennell Allman my exors adñiors and assigns and such others as I the
said Fennell Allman my exors adñiors or assigns should at any time agree
with and no others from time to time and at all times thereafter during the
term, of years..therein mentioned should and lawfully night make. use
exercise and vend within that part of the United Kindom of Great Britain
and, Ireland called, England the Dominion of Wales and the Town of Ber-
wick-upon-Tweed the Islands of Jersey Guernsey Alderney Sark and Man
audall. Her said Majesty's Colonies and Plantations abroad ny Invention of
CERTAIN IMPROVEMENTS IN APPARATUS FOR THE PRODUCTION OF LIGHT, FROM
ELECTRICITY" in which said. Letters Patent there is contained a proviso that
Lthe said Fennell Allman shall particularly describe and ascertain the
nature of my Juvention and in what manner the same is to be performed
by, an instrument in writing under my hand and seal to be enrolled in Her
said Majesty's, High Court of Chancery within six calender months next after
the date of the said, in, part, recited Letters Patent as reference being there
unto had will more fully, and at large appear.

page_text: NOW KNOW YE that in compliance with the said proviso I the
said Fennel Allman do hereby declare the nature of my said Invention and
in what manner, the same is to be performed to be particularly described
and ascertained as follows reference being had to the Drawings hereunto
annexed and to the letters and figures marked thereon (that is to say)
My Invention of Improvements in apparatus for the production of light
from electricity relates to the arrangements in connection with the electrodes
poles or luminous terminals for the purpose of regulating and maintaining
them in a position suitable for the production and maintenance of the electric
light and also to the battery or source of electricity.
I will proceed first to describe that part of my Invention which relates to
the arrangements in connection with the electrodes or that part of the voltaic
circuit at or in which the phenomenon of light is produced. It is well
known that there are certain conditions most advantageous for the production
of light from electricity and these conditions are generally understood but in
their attainment many difficulties occur of a practical nature. The light is
best developed by breaking the circuit or conductor and placing a piece of
carbon at the end of the wire or conductor on either side of such. break in
the circuit of one piece of carbon on the positive or giving pole and platinum
iridium or any comparatively infusible metal or conductor on the negative
or receiving pole. These pieces of carbon platinum or other substances are
commonly called electrodes poles or terminals. One great difficulty in
attaining a steady and permanent light results from the necessity of a com-
pliance with the following conditions-First, The electrodes between which
the circuit is broken should be in contact so as to complete the circuit pre-
viously to the circuit being broken. Secondly-The electrodes should be
separated one from the other to a certain limited distance depending on the
quantity and intensity of the current employed and the resistance to its pas-
sage and other circumstances. Thirdly. The maintenance of the electrodes or
of their terminal surfaces at such certain limited distances apart under the
variations to which the current is subject and the destruction and alteration
of the electrodes from consumption dissipation or other cause. Various
means have been resorted to and arrangements proposed for effecting this
object. Thus it has been proposed to employ continuous conductors of pla-
tinum iridium carbon &c. in a state of division also dust of carbon also
to regulate the distance between the electrodes by a train of wheelwork
resembling clockwork lifting one of the electrodes the rate at which the
clock work is to move being adjusted according to the power of the battery
employed for the production of the light. It has also been proposed to

page_text: employ flat discs of carbon the light being developed between their edges;
also sticks of carbon resting on non-conductors. It has also been proposed
to make the current of electricity traverse a coil of wire or conductor and
cause an iron cylinder within the coil to rise and fall according to the quantity
of electricity passing and in so doing to govern the mechanism employed to
regulate the distance between the electrodes. But these and other means of
attaining the same ends are subject to various defects which interfere with
their practical efficiency, and the object of this part of my Invention is to
attain these ends with greater simplicity certainty and economy than here-
tofore. In the arrangements herein-after described in reference to this part
of my Invention the same electric current that produces the light separates
the electrodes and at the same time keeps them separate and maintains them
at the requisite distance.
One of the arrangements which I employ for this purpose consists of a
permanent magnet and conductor. This I will now proceed to explain by
reference to Sheet A of the annexed Drawings in which the same letters
indicate the same parts throughout. aa Fig. 1 Sheet A denotes a per-
manent magnet constructed of a number of plates of steel combined together
each plate having been rendered permanently magnetic in the usual way. The
thickness of each plate is given in the section Fig. 2 This compound magnet
is capable of turning on the centres in the spindle fixed in the
frame d which binds the plates of the magnet together. Immediately above
the magnet and parallel therewith is placed a horizontal coil of copper wire
or ribbon prepared or insulated in the manner usually adopted in electro-
maguetic apparatus. This coil I make to consist of about twenty-four
convolutions of copper ribbon covered with some non-conducting material.
When the poles of the battery are connected with this arrangement and the
current of electricity is caused to pass through the apparatus it enters at
circulates through the coil round the magnet a from thence it passes to the
brass clamp and through a slip of thin silver foil y into the electrode
holder to the upper electrode from the lower extremity of which it passes
to the lower electrode i and its holder j and thence through the conductors/
and back to the battery. The wheels aaa are not essentially necessary
being merely friction wheels adapted to the upper holder to guide the
same and facilitate the upward and downward action of the holder and
working of the apparatus in case of rust or other impediments. The electric
current by thus traversing the apparatus produces the following results :'
First the well-known deflection of the magnet « which is deflected so as to
separate the electrodes by lifting the holder of the upper electrode by the

page_text: connecting link me: and secondly the production of light at the extremi-
ties of the carbon terminals poles or electrodes h and i. Now the elec-
trodes by the action of the weight n fixed on the spindle of the magnet a are
kept in contact before the current is turned on or when it is broken, but
when the current is turned on the deflection or motion of the magnet or
needle a separates the upper electrode as before described from the lower
electrode . Thus the two first necessary conditions are obtained (viz.) the
primary contact of the electrodes or terminals and their subsequent sepa-
ration. The other or third condition (viz.) that the electrodes should separate
to only the proper distance is a necessary consequence of the conditions
produced by the above arrangements for as the separation of the electrodes
is caused by the action of the electric or voltaic current on the magnet
and as too great a separation after contact would destroy the current and as
the electrodes are always kept in contact by the weight or when the current
is destroyed, it results that the current under these conditions will not destroy
itself by too great a separation of the electrodes, but a small separation will
be produced and maintained. The cause and effect mutually govern each other
thereby producing a self-acting apparatus depending only on the supply of a
sufficient electric current and being entirely independant of auxiliary gover-
nance or adjustment. The apparatus or lamp as shewn in the Drawing
has the magnet a parallel to the coil but when the apparatus is put in
action it is necessary to push the lower electrode contained in the tube j
upwards lifting at the same time the upper electrode h' the holder / and
causing the end of the magnet a to deflect in a corresponding direction until
it is at an angle of say about thirty degrees with the direction of the current
in the coil a'. A wider coil will give a longer deflection that is it will exhibit
the necessary repulsive force at a greater angle. The lower electrode being so
pushed up with the upper one 'resting thereon if the current be made to
traverse the copper coil a' it will at once separate the electrodes to the required
distance and preserve thein so until the magnet by the destruction of the elec-
trodes returns to a position parallel to the coil a'. The weight o is merely a
balance to the weight of the electric holder. The weight n or the force to act
against or antagonistic to the dynamic effect of the current produces steadiness
and prevents flickering or jumping of the electrode but must not be so heavy a
to prevent a separation ofthe electrodes. This weight can be adjusted as shewn
in the Drawing so that by means of the screw pit can be brought nearer to or
further from the vertical position and it can also be screwed on the spindle nearer
the spindle of the magnet a. In using an antagonistic force as this weight
it is necessary that as the deflective force of the magnet diminishes as its
72

page_text: angle with the conductor increases the antagonistic force should also diminish
in a like ratio as the said angle increases In this apparatus it is accomplished
by the said weight being brought more over the centre of the deflection.
Its force or weight consequently diminishes as the angle increases.
Fig. 3 is a plan of the weight and spindle c, Fig. 4 is a detached
sectional view of the holder at 22, and Fig. 5 is a section of one of the
antifriction wheels a. In this apparatus I have shewn how the com-
bination of permanent magnets and conductors may be used for the purpose
set forth by means of repulsion but it will be obvious that the separation
and maintenance of the electrodes at the required distance apart may be
effected by attraction as herein-after more particularly described. It will also
be obvious that the peculiar shape construction and general arrangement of
the permanent magnets and conductors and electrodes may be varied according
to circumstances and I claim as of my Invention and the exclusive use of a
conductor or conductors of voltaic or other electricity in combination with
a permanent magnet or permanent magnets as an improvement in apparatus
for the production of light from electricity.
Sheet B Fig. 1 exhibits another combination or arrangement of apparatus
for the production of light from electricity being a combination of permanent
and induced or temporary magnets. a a is a permanent magnet similar to
the magneta in Sheet A. A similar deflection which is well understood is
produced in it so as to cause the magnet to turn on the centres & by the
repulsive effects between the similar poles c and d of the induced magnet d
and the poles of the permanent magneta. The current enters at a from
whence it flows through a coil of copper wire or ribbon prepared or insulated
in the usual manner around the soft iron c which thus becomes a magnet by
induction the magnet with its coil being contained in the brass tube or case d.
The electric current passes from the coil through the frame e to the other
induced similar in arrangement to that just described around which
it also circulates thence through the copper band finto the support y and
by the slip of silver foil into the upper electrode holder i to the upper
electrode and from thence to the lower electrode and through the holder
back to the battery. The apparatus is prepared for action in the same
manner as that shewn in Sheet A that is by pushing up the lower electrode
and thereby increasing the distance between the respective poles of the
magnets then if the current is turned on the electrodes (resting one on the
other as in Fig. 1 Sheet A) will be separated to the requisite distance
governed by the weight which is similar in its office and effects to w
Sheet A Fig. 1. The same remarks as to construction equally apply to both

page_text: arrangements. The balance weight is employed as a counterpoise as m
Sheet A. Fig. 2 is an end view of Fig. 1, Fig. 3 represents a section of
one of the induced magnets Fig. 4 is a transverse section of the same.
Fig. 5 is a plan of one of the permanent in ignet plates, and Fig. 6 an edge
view of the same.
In this combination of permanent magnets combined with induced or
temporary magnets the arrangement construction shape and configuration
of the several parts may be varied and I claim as of my Invention and the
exclusive use of permanent magnets in combination with induced or temporary
magnets as an improvement in apparatus for the production of light from
electricity.
Sheet C exhibits a general elevation (part in section) of an apparatus by
which I am enabled to employ another of the dynamic effects of the voltaic
current (namely) the repulsion between similar poles of induced or temporary
magnets only,such induced magnets consisting of softiron rendered magnetic
during the transit of an electric current through a coil of covered copper
wire or ribbon as described in reference to Sheet B. When these magnets
are rendered magnetic under the influence of the voltaic current the approxi-
mate poles and e and d¹ and e¹ of the magnets are similar. This is caused
by making the current to circulate in the proper direction around the soft
iron as is well known but the magnets a and a¹ are fixed on either end of
the balance rod cc to which is connected by the arm and connecting link y
the upper electrode holder so that any motion caused by the movement of
the rode on its centre c' is thus communicated to the electrode 7. Now the
action is as follows: The electric current enters the apparatus at and
circulates round the magnet 6 into its brass case which covers the conductor
then through a slip of silver (sufficiently flexible to admit of the magnets
a and b separating around the other magnet through the rod into and
round the magnet a¹ at the opposite end from which it circulates round b¹ and
through the slip of silver m to the upper electrode holder into the upper
electrode i to the lower electrodej through the lower holder n rod o and con-
ductor p back to the battery. The part colored red in this as well as in the other
Sheets of Drawings denotes where it is necessary to place a non-conducting sub-
stance to prevent the current from diverging from the proper circuit. In this
apparatus no permanent magnets are used. Now the effect of sending a current
of electricity through the apparatus is first to render magnetic the several soft
iron pieces under its influence simultaneously. The immediate consequence is
that the said electro-magnets a and a¹ repel band b¹, butas band blare fixtures
a and a move away from them being permitted to do so by the movement of

page_text: the bar or lever con its centre and the flexibility of the conductors of silver
between these magnets but this separation of the magnets separates also the
electrodes as the bar or lever c' lifts the holder has before explained. The
dynamic effectthereforeexhibited by the repulsion between the magnets tends to
separate the electrodes i andj, but as it is the current that thus produces this
separation and as too great a separation would destroy the said current it will
only separate the electrodes to a certain distance the cause and effect being in
equilibrium this distance being that which is necessary for the production
of the light between the electrodes i and j. By pushing the bottom electrode j
up it will move the magnets a and a from the magnets and which will
again approach each other as the electrodes are diminished from any of the
causes incident to the operation of the apparatus. The results obtained in
this self-acting apparatus are the same as the others in Sheets A and B but
the mode of employing the electric current is different. In this combination
in which induced magnets only are employed if I were to remove the soft iron
from the centre of the conducting coil the same effects would then be produced
but in a minor degree. The arrangement would then consist of the repulsion
between similar poles of conductors only, and such an arrangement may also
be employed for the production of light from electricity. The peculiar form
of the several parts referred to may be varied and I claim as of my Invention
and the exclusive use of conductors arranged so as to produce a mutual
repulsion as an improvement in apparatus for the production of light from
electricity.
In Sheets B and C I have shewn the apparatus as actuated by the repulsive
effects between similar poles of magnets, but if opposite poles were placed in
proximity to each other attraction would ensue between the opposite poles.
If the apparatus were thus changed by reversing the poles and position of the
induced magnets or conductors it will be evident that the motion in the
parts caused by the said attraction could be used to separate the electrodes
and maintain them separate and produce the same results as the repulsive
effects herein-before explained, and I claim as of my Invention the exclu-
sive use of induced magnets and conductors or conductors cnly in combina-
tion and acting by attraction or repulsion as an improvement in apparatus
for the production of light from electricity.
Sheet D Fig. 1 represents a side view of another arrangement of apparatus
for the production of light from electricity. aaa is a lever having one end
turning freely on the fixed centre band the other end attached to the upper
electrode holder ccc by a piece of wire cord. d. The wire cord which I
prefer is that commonly known as Newall's Patent wire rope or cord.
This

page_text: cord is soldered both to the lever a and electrode holder c to ensure a good
connection. Any upward movement therefore of the lever on its pivot or
centre b would lift the electrode e from the lower electrodef but the spring g
constantly presses the lever a in this direction and would consequently if not
controlled separate the electrodes. This however is prevented by the com-
pound bar or rod hi which is fixed to the plate l. The upper end of the
bar or rod i being screwed receives a milled nut m which is screwed down on
to the spring until it so acts against the spring gas to keep the electrodes e
and together. This compound rod or bar hi has a cock n and into which
the lower piece is fitted by a nonconducting bushing as shewn colored red!
I would here observe that all the parts colored red are made of noncon-
ducting substances. Now the current of electricity upon entering by the
copper ribbon o passes up the bar through the plug n of the cock through
and the spring to the lever a aa then along the cord and the holder to
the electrode e and thence to the lower electrode the holder p and con-
ductor back to the battery. The plug of the cock n (which is on one part
filed flat) being in the position shewn in the Drawing that is so placed that
the flat part is in some measure presented to the conductor it does not afford
a sufficient conducting surface of contact between the plug and bar h. The
result is that as this surface contact is diminished by turning the cock the
cock and bars h and i become heated by the passage of the current and this
heating effect cau by setting the plug n of the cock be made to suit the
quantity or nature of the current employed so that a given current shall
always produce a given heating effect or heat the rod i as much as necessary.
But the same current passes also from one electrode to the other as before
described and when the rod i becomes heated it expands and by its elonga-
tion allows the spring g to separate the electrodes e and by lifting the lever a
as described. When the current is cut off the bar hi cools and the electrodes
return by its contraction into contact.
Fig. 2 is a detached view of the fork of the bracket and lever, the latter
being shewn in section.
In Fig. 3 I have shewn another way in which the heating effects of the
current may be made to govern the position of the electrodes e and f. This
is effected with the assistance of a compound barst the electric current
being sent through the bracket u into the bar st across the link which
couples it to the lever a and thence as before through the electrodes to the
battery the barst being made of such a size that the current will by
passing through it heat it sufficiently to cause it to curve or bend upwards
t being the convex and s the concave side of the curve owing to the unequal

page_text: expansion under a similar temperature of the brass bart and steel s which are
rivetted together by the rivets aaa. This curving of the bar it is evident
will by lifting the lever « by means of the link v separate the electrodes. As
in either of these arrangements the current by thus separating the electrodes
tends to destroy itself it will be evident that by turning the cock n or propor-
tioning the size of the barst the cause and effect as to heating and separation
will mutually govern each other.
In this Sheet I have shewn how the calorific effect of electricity may be
employed in an apparatus for the production of light from electricity. The
same effects may be produced by a variety of other similar arrangements in
which the calorific or heating effects of the current may be rendered available
for separating the electrodes and maintaining them at a distance from
proper
each other. And 1 claim as my Invention and the exclusive use of an
arrangement of apparatus whereby the heating effects of electricity may be
employed and rendered available in and for the production of light from
electricity.
Sheet E represents an apparatus by which the decomposing effects of the
voltaic current may be employed to regulate the electrodes poles or luminous
terminals of the voltaic circuit. The same apparatus may also be employed
to indicate the intensity effects (commonly so called) of the voltaic circuit.
aaa is the brass frame in which the brass tube b¹ slides vertically. The
open or lower end of this tube is fitted into the cover or air-tight lid of the
glass cylinder dd d. This cylinder d contains two platina plates e e¹ of the
size shewn in the Drawing and about two and a half inches wide and placed
about one quarter of an inch apart, these plates act as a common volta-meter.
An exterior concentric glass vesself surrounds the cylinderd and contains the
liquid for decomposition. The action of the apparatus will be as follows-
When the circuit is made the currententers at g through the spring conductor h
into the arm to the plate e across to the plate e¹ as the arrows indicate to
the other arm and through the other elastic conductor h' to the lower elec-
trode holder; and electrode k and thence to the electrode and conductor m
back to the battery. The effect of the current of electricity so traversing the
apparatus is first that the liquid (sulphuric acid and water) is decomposed
and the gases given off in rising enter the sliding tube 6 but as they accumu-
late the cylinder & with the contained plates e and e' is lifted and slides
upwards by the guide tube b against the pressure of the guide springs
h and h¹. The gases will now have no aperture to escape by unless
the screw n be unscrewed the cone point of which screw is shewn in the

page_text: 9
Drawing as entering the tube at o. The hole o will by being thus opened
allow the gases to escape but if this egress for the gases be insufficient they
will lift the cylinder d by accumulation until the condensation produced
by the reaction of the spring conductors hand forces the gases out at
the said hole o. If the decomposition be at the rate of twenty cubic inches a
minute as a constant quantity and supposing the hole be opened a little
and the cylinder d rises half an inch it will be evident that if the quantity of
gasos increase say to thirty inches per minute they cannot escape through the
same sized aperture at the same pressure or condensation. They will conse-
quently lift the cylinder dand thus obtain a greater pressure from the springs
hh when the thirty inches per minute will be enabled to escape through the
same aperture o.
Now on the tube b is a button which holds down the
ends of the levers 7 which turn on the centress and s' but the end of the
lever is as shewn in the Drawing connected to the lower electrode slide
holder which is capable of sliding up, and down, the current therefore
when turned on first decomposes the fluid and by thus lifting the cylinder d
the tube b and button 9 lowers the outer end of the lever 7, but this would
separate the electrodes and consequently produce the second proper condition
for the production of light as too great a separation would destroy the current
and consequently destroy the decomposing effects or the cause of the separa-
tion. The electrodes will therefore remain apart the proper distance for the
production of light. The other lever is used as an indicator the rise and
fall or fluctuations of which will denote the variation in intensity in the
current of electricity passing through the apparatus. The electrodes are
shewn enclosed in a glass vessel made as air tight as possible. In this Sheet.
I have shewn one method of using the decomposing effects for the production
of light. but it will be obvious that other arrangements of apparatus may be.
employed for the same purposes.
:
I claim as of my Invention and the exclusive use of apparatus so arranged.
as to render available the decomposing effects of the voltaic current or a
current of electricity for regulating the, electrodes as an improvement in
apparatus for the production of light from electricity.
I also claim as of my Invention and the exclusive use of the volta-meter
above described as an improvement in apparatus for the production of light.
from. electricity.
The Figures in Sheet F represent the part of my Invention which relates.
to the apparatus employed as the source of electricity. This improvement:
consists in certain arrangements and apparatus for regulating the emission of

page_text: the fluids of the battery and the ingress also of the fluids. In Fig. 1a a a
is a syphon the broken end of which is connected with that part of the battery
from which the liquid is to be drawn. The other end is shown immersed in a
glass vessel b into which it discharges, but this glass vessel is kept constantly
full and is suspended by an arm to the pin c of the leverd which turns on the
fixed centre.
The glass vessel 6 is balanced by the weight e. The top of
the vessel must be a little below the level of the liquid in the battery so that
the discharging leg of the syphon immersed therein may be made a little
longer or deeper. Now if the syphon should draw off very heavily saturated
solution such for example as sulphate of zinc the vessel being always full
will by its increased weight fall lower and by its thus lengthening the dis-
charging leg of the syphon will increase the discharge until it begins to
draw off liquid not so heavily saturated when it will lessen the discharge by
rising again. The same object is accomplished as seen in Fig. 2 by the ball a
rising when the liquid whose level remaining at y becomes more heavily
saturated. By thus rising it opens the discharge pipe b by the throat valve c
which valve it again shuts when the ball sinks to the standard level due to
the proper saturation of the liquids drawn off; the pipe is supported by the
bracket I prefer that all the battery apparatus in this Sheet F when the
shape admits of it should be made of glass earthenware or other similar
materials.
"
And I claim as of my Invention and the exclusive use of apparatus so
constructed and arranged as that the variation in the specific gravity or degree
of saturation or exhaustion should be made to regulate the discharge of the
liquids from the battery as an improvement in apparatus for the production of
light from electricity. In some cases I employ pumps or other hydraulic
apparatus as usually constructed and employed for forcing and drawing fluids
or liquids to force or draw the liquids used in the battery. The apparatus so
employed should be made of glass porcelain platinum or some material not
ordinarily acted on by the liquids employed. The circumstances under which
I employ this hydraulic apparatus are when the battery is a great distance
from the acid or supply reservoir or where there is a great difference in the
level of acid or liquid cistern and the battery or in cases in which a syphon
as already described is inapplicable and cannot be employed with advantage,
and hydraulic apparatus may also be useful under certain circumstances in
saving labour time and expense in working the batteries and in economizing
room for the plant.
Lastly I claim as of my Invention the exclusive use of hydraulic apparatus

page_text: which requires to be worked by power or force adapted to and in combination"
vith the voltaic battery as animprovement in apparatus for the production of
ight from electricity.
In witness whereof I the said Fennell Allman have hereunto set my
hand and seal this Twenty-seventh day of March in the year of
our Lord One thousand eight hundred eight hundred and forty-nine.