IMPROVEMENTS IN ELECTRIC LAMPS
Year: 1879

page_text: LETTERS PATENT to Charles Denton Abel, of Southampton Buildings, Chancery
Lane, in the County of Middlesex, for the Invention of "IMPROVEMENTS IN
ELECTRIC LAMPS." A communication from abroad by Jules Celestin Jamin, of
Paris, in the French Republic.
Sealed the 11th July 1879, and dated the 4th March 1879.
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at the
Office of the Commissioners of Patents on the 4th March 1879.
CHARLES DENTON ABEL, of Southampton Buildings, Chancery Lane, in the
County of Middlesex. "IMPROVEMENTS IN ELECTRIC LAMPS." [A communication
from abroad by Jules Celestin Jamin, of Paris, in the French Republic.]
It is found that the luminous are of electric lamps obeys the laws of Ampère in
precisely the same manner as an ordinary electric current; that is to say, it is
attracted or repelled by electric or magnetic currents passing through metallic
conductors in various directions, and it can be made to revolve round an axis under
the influence of a magnet or solenoid. According to the present Invention this
property of the luminous arc is utilized in order to modify and determine its
position and mode of action in various ways in electric lamps. Thus according to
one arrangement if two carbons be placed parallel to each other a small distance
apart, and the electric current before passing through them be made to pass through
a wire loop running parallel with the carbons on each side thereof and across their
terminals, the current be made to pass through the loop in the same direction to
that in which it passes through the carbons; then assuming that the luminous are
passes in the first instance from an intermediate point of the length of one carbon
to the other, it will be influenced by the current in the wire loop so as to move
towards that point where it will be nearest to the part of the loop in which the
current flows in a direction parallel to its own direction, that is to say, it will move
to the two terminals of the carbons and will be maintained there while the carbons
burn away. The carbons may be arranged with their terminals upwards or down-
wards, and they may be either fixed or each one be mounted on a pivot, so that
when no current is passing, their terminals are brought together by the action of a
spring, while on the passing of a current this in passing through the wire loop
attracts the carbons, so as to move them apart and thus produce the luminous aro.
The lower ends of the carbons are connected to the circuit either by coils or by
[Davis 1

page_text: cups containing mercury, so as to allow of their motion. Instead of the wire loop
a magnet or solenoid may be applied near the terminals of the carbons in such a
position that its action corresponds to that of an electric current flowing parallel
with the luminous arc.
According to another arrangement in place of the form of wire loop above
described two conducting wires are formed so as to run parallel with the carbons
respectively from either end thereof, and at a certain point to turn off at right
angles to these. The luminous are will then pass from the one carbon to the other
at an intermediate point nearest to that where the wires turn off at right angles,
and the carbons in being consumed at that point will each eventually be divided
into two parts. The upper parts of the two rods being supported loosely in tubes
will then gradually descend as they are consumed, while the lower parts remain
practically unconsumed.
According to another arrangement an ordinary electric lamp with the two carbons
end to end and adjusted by a regulator has placed at the terminals of the carbons a
magnet or solenoid at right angles to the carbons with the poles presented to the
terminals thereof. The effect will be to project the electric spark in a more or less
diffused manner and with little luminosity in a direction at right angles to the
carbons on the side opposite to that on which the magnet is placed. By placing at
the point to which the spark is projected a piece of lime or other refractory body,
ór even carbon, this will be raised to a white heat by the high temperature of the
spark and will give out an intense light. The same effect may be produced by
means of the well known "Jablochkoff candle" by imbedding the one side of the
entire length of each carbon in lime, kaolin, or other suitable refractory substance,
and applying the magnet or solenoid to the opposite or non imbedded sides of the
carbons.
According to another arrangement an ordinary carbon rod is placed parallel but
in the opposite direction to a broad carbon plate which presents its edge to the rod,
and the circuit wire is made to pass from the socket of the carbon rod parallel with
the carbon plate towards the socket thereof, and is then turned off at right angles.
Thus the current being made to pass along the carbon plate and across to the rod
would produce the luminous are at any point in the length of the latter; but the
attraction exercised by the current in that part of the conducting wire which
passes away at right angles to the carbons will cause the luminous arc to be formed
at the extreme end of the rod, which will gradually burn away, the carbon plate
being but slightly affected.
According to another arrangement two carbons placed end to end, as in an
ordinary lamp, have placed round one or both of them a coil or solenoid through
which the current of the lamp is passed, the effect of which will be to cause the
luminous arc to revolve very rapidly round the carbons in a direction corresponding
to that of the current passing through the solenoid; by this means the carbons will
be consumed with great uniformity and without that fluctuation of the light which
at present takes place.
According to another modification of this arrangement the lower carbon is
formed as a hollow cylinder, within which is placed a mass of lime or other suitable
refractory material raised somewhat above the cylinder. The upper carbon being
allowed to rest upon the lime, and the cylinder being surrounded by a solenoid, the
luminous are passing from the cylinder to the carbon rod will revolve rapidly
round and round the cylinder, as before described, the carbon rod descending as it
is consumed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Denton Abel in the Great Seal Patent Office on the 24th.
July 1879.
CHARLES DENTON ABEL, of Southampton Buildings, Chancery Lane, in the
County of Middlesex. "IMPROVEMENTS IN ELECTRIC LAMPS." A communication
from abroad by Jules Celestin Jamin, of Paris, in the French Republic.
It is found that the luminous are of electric lamps obeys the laws of Ampère in
precisely the same manner as an ordinary electric current, that is to say, it is
attracted or repelled by electric or magnetic currents passing through metallic
conductors in various directions, and it can be made to revolve round an axis under
the influence of a magnet or solenoid.
According to the present Invention this property of the luminous arc is utilised
in order to modify and determine its position and mode of action in various ways
in electric lamps. Thus according to one arrangement if two carbons be placed
parallel to each other a small distance apart, and the electric current before passing
through them be made to pass through a wire loop running parallel with the
carbons on each side thereof and across their terminals, the current being made to
pass through the loop in the same direction to that in which it passes through the
carbons; then assuming that the luminous are passes in the first instance from an
intermediate point of the length of one carbon to the other, it will be influenced by
the current in the wire loop, so as to move towards that point where it will be.
nearest to the part of the loop in which the current flows in a direction parallel to
its own direction, that is to say, it will move to the two terminals of the carbons
and will be maintained there while the carbons burn away. The carbons may be
arranged with their terminals upwards or downwards, and they may be either fixed
or each one be mounted on a pivot, so that when no current is passing their
terminals are brought together by the action of a spring, while on the passing of a
current this in passing through the wire loop attracts the carbons so as to move
them apart and thus produce the luminous arc. The lower ends of the carbons are
connected to the circuit either by coils or by cups containing mercury, so as to
allow of their motion. Instead of the wire loop a magnet or solenoid may be
applied near the terminals of the carbons in such a position that its action corre-
sponds to that of an electric current flowing parallel with the luminous arc.
According to another arrangement in place of the form of wire loop above
described two conducting wires are formed so as to run parallel with the carbons
respectively from either end thereof, and at a certain point to turn off at right
angles to these. The luminous are will then pass from the one carbon to the other
at an intermediate point nearest to that where the wires turn off at right angles,
and the carbons in being consumed at that point will each eventually be divided
into two parts. The upper parts of the two rods being supported loosely in tubes
will then gradually descend as they are consumed, while the lower parts remain
practically unconsumed.
According to another arrangement an ordinary electric lamp with the two carbons
end to end and adjusted by a regulator has placed at the terminals of the carbons
a magnet or solenoid at right angles to the carbons with the poles presented to the
terminals thereof. The effect will be to project the electric spark in a more or less
diffused manner and with little luminosity in a direction at right angles to the
carbons on the side opposite to that on which the magnet is placed. By placing at
the point to which the spark is projected a piece of lime or other refractory body,
or even carbon, this will be raised to a white heat by the high temperature of the
spark and will give out an intense light. The same effect may be produced by means
of the well known "Jablochkoff candle" by imbedding the one side of the entire
length of each carbon in lime, kaolin, or other suitable refractory substance, and

page_text: Fig. 1 shews a simple arrangement of electric lamp operating according to one of
the methods above described; A, B, B', A¹, is a conductor which may form part of
the lamp circuit or of another circuit. It is arranged outside two parallel carbons
C, D, C, D¹, fixed at a little distance apart, without any nonconducting material
between them. The current in the external conductor determines that the current
through the carbons shall form the voltaic arc between their extremities C, C¹; for
if, owing to proximity or other causes the arc should present itself at some inter-
mediate point m, it will be attracted upwards till it becomes established as near as
possible to the parallel current B, B¹, that is to say, at C, C¹, and it will remain at
the extremities of the carbons as they are consumed. The arrangement may
obviously be employed in an inverted position, but in that case the arrangement
shewn in Fig. 2 is to be preferred. Here the external circuit C, B, A, a, c, makes
several successive convolutions along insulated wires or thin strips of metal. The
carbons are held in guide tubes D, D', E. E¹, and when after they are partly con-
sumed it is desired to lower them so as to bring the arc down to its focal position
they may be pushed down by pulling a sliding piece D, E, that extends across from
tube to tube through slits along their sides. The string or wire attached to the slide
D, E may be connected to a float in a vessel containing liquid which is timed to run
out and allow the float to descend at a rate corresponding to the consumption of the
carbons. For the purpose of kindling the lamp the ends of the carbons may be
sprung together and held by a small caoutchouc band or cement paste. When
the lamp is put in circuit the heat evolved at the ends of the carbons
consumes the band or cement, allowing the carbons to spring apart, the voltaic are
being established between them. According to another method there is placed
behind the carbons near the points D¹, E¹, where they issue from the guide tubes,
an electro-magnetic arrangement for kindling, such as is shewn at Fig. 3. G, H, is
an armature lever pivotted at O, and carrying a piece of carbon I which lies against
the carbons, as indicated at I in Fig. 2. When the lamp is put in circuit (of which

page_text: the coil of the electro-magnet in Fig. 3 forms part) the piece of carbon I starts the
are and is then withdrawn from the carbons by the attraction exerted by the
electro-magnet on the armature lever G, H. The arc started at I descends the
carbons to their ends in obedience to the attractive influence of the circuit C, B, A.
When the lamp described works with an alternating current the consumption of
the two carbons is the same. When a current of constant direction is employed
the different rates of consumption of the two carbons may be provided for either
by making one thicker than the other, or by arranging in the circuit a commutator
which at certain intervals, such as five or six minutes, changes the direction of the
current through the carbons. Fig. 4 shews a modified arrangement in which the
carbons are held in sockets pivotted to the framing with a spring interposed
between them, which causes the upper ends C, C¹, of the carbons to meet. The
sockets D, D', that hold the carbons may be connected to the circuit by flexible
wires, or, as shown in the Figure, by conductors dipping into insulated basins of
mercury. When the lamp is put in circuit the are presents itself at the meeting
points C, C¹, but the attraction of the external circuit A, B, B¹, A', causes the
carbons to separate, the arc being still maintained between their points. Should
the electric force vary, the carbons will oscillate a little to or from each other, as the
case may be, taking a position such that there is equilibrium between the force of
the spring r and the attractive influence of the outer circuit. For this outer circuit
may be substituted an electro-magnet, operating in the manner indicated by the
diagram, Fig. 5. Assuming the line C, D, to represent the carbons and C, M, the
centre line of an electro-magnet, then the arc will always take the attitude C, K,
perpendicular to C, M. In the arrangement shewn in side view at Fig. 6, and in
plan at Fig. 7, the carbons are placed end to end as in ordinary regulator lamps,
but a pair of solenoid coils 8, c, 8, d, are bent round so as to present their ends at
the opposite sides of the arc, which has the effect of projecting it against a bar L of
lime, that becomes intensely heated and gives out a bright white light like the
lime or Drummond light. A like lime-light effect may be obtained by a modifica-
tion of the Jablochkoff candle, as shewn in sectional plan at Fig. 8. The two
parallel carbons C, C¹, instead of being simply separated by a small layer of
calcareous matter are partly embedded in a slab X of plaster of Paris. According
to the arrangement shewn in side view at Fig. 9, and in plan at Fig. 10, one of the
carbons C, D, is in the form of a broad thin plate, presenting its edge to the other
carbon C, D. The direction of the external current B, A, is such as to bring
the arc down from any place, such as m, to the extreme end of the carbon C¹, DP,
and as it is consumed the arc merely travels up the edge of D, C, following the end D¹,
there being very little waste of the plate C, D. In order to provide against the
variations of luminosity in an ordinary regulator lamp one of the carbons is
surrounded by a solenoid coil, as shewn in Fig. 11. The current in this coil has
the effect of making the arc m revolve round the axis of the carbons with a velocity
so great that the irregularities are very rapidly repeated, and a practically constant
light is maintained. According to the arrangement shewn at Fig. 12 the upper
carbon C, D, rests on a block f of lime or other insulating infusible material enclosed
within a carbon tube e, which is surrounded by a solenoid coil h. The arc is caused
to whirl rapidly round the axis of the carbons, gradually consuming and dissipating
the carbon tube e and the block f. The consumption of these is however so slow
that the light remains for a long time nearly in the same position, and the arc
revolves so rapidly that the light remains practically constant.
Having thus described the nature of this Invention, and in what manner the
same is to be performed, as communicated to me by my foreign correspondent, I
claim in respect of electric lamps,-
First. Arranging near the carbons an electric directing circuit in which the
currents are so directed as to attract the voltaic arc to the points of the carbons,
substantially as herein described with reference to Figs. 1, 2, and 4 of the accom-
panying Drawings.

page_text: Second. The modified arrangement in which a thin plate is employed as one of
the carbons, substantially as described with reference to Figs. 9 and 10.
Third. In a lamp arranged in the manner referred to in the first claim mounting
the carbons on pivots with a spring pressing their points towards each other so
that their distance is automatically adjusted by the influence of the electric directing
circuit, substantially as described with reference to Fig. 4.
Fourth. The arrangement, substantially as described with reference to Fig. 3, for
effecting the kindling of an electric lamp by means of a carbon match bearing
against the carbons until it is removed from contact by the action of an electro-
magnet whose coil is in the lamp circuit.
Fifth. Applying near the points of the carbons solenoid coils, so arranged as to
protect the voltaic are against a plate or bar of lime, substantially as described with
reference to Figs. 6 and 7.
Sixth. Arranging around one of the carbons a solenoid coil for the purpose of
causing rotation of the arc, substantially as and for the purposes herein set forth
with reference to Figs. 11 and 12.
Seventh. The arrangement of lamp herein described with reference to Fig. 12,
wherein the voltaic arc is caused by the action of a solenoid coil to rotate round the
edge of a tubular carbon enclosing a block of calcareous or such like material
sustaining the other carbon in form of a rod.
Eightb. The modification of Jablochkoff electric candle as herein described with
reference to Fig. 8.
In witness whereof, I, the said Charles Denton Abel, have hereunto set my
hand and seal, this Twenty fourth day of July, in the year of our Lord
One thousand eight hundred and seventy nine.