IMPROVEMENTS IN ELECTRIC LIGHTING, AND IN THE MEANS OR APPARATUS EMPLOYED THEREIN
Year: 1879

page_text: LETTERS PATENT to Charles Weightman Harrison, of 27, Southampton
Buildings, in the County of Middlesex, Gentleman, for the Invention of
"IMPROVEMENTS IN ELECTRIC LIGHTING, AND IN THE MEANS OR APPARATUS
EMPLOYED THEREIN."
Sealed the 23rd March 1880, and dated the 25th September 1879.
PROVISIONAL SPECIFICATION left by the said Charles Weightman Harrison
at the Office of the Commissioners of Patents on the 25th September 1879.
CHARLES WEIGHTMAN HARRISON, of 27, Southampton Buildings, in the County
of Middlesex Gentleman. "IMPROVEMENTS IN ELECTRIC LIGHTING, AND IN THE
MEANS OR APPARATUS EMPLOYED THEREIN.'
"
This Invention relates to improvements in electric lighting, and in the means or
apparatus employed therein.
Firstly. In the manufacture of carbon burners or electrodes I compose them of
pure lamp black and napthaline dissolved in boiling tar, which I knead together
to form a mass that will cohere when pressed. I place the compound while still
hot into heated metal moulds of any required form, and by means of powerful
pressure produce a dense solid, which is afterwards packed with powdered chalk
in clay crucibles, and burned at a high temperature for some hours.
My improvements relate, secondly, to a regulator for electric lighting, which I
partly construct by mixing together a conducting and non-conducting powder,
lamp black answering very well as a base for the first and chalk for the second.
With these I form a scale commencing with lamp black and finishing with chalk.
the intervening space being filled with the mixture in varying proportions to repre-
sent successive units of resistance. I mould these into small slabs, and bake them
in a close crucible, and when ready I fix them in a dial communicating with
the circuit, whilst an adjustable slide also in communication makes contact with
the various slabs and controls the passing current.
My improvements also comprise several forms of lamps. First, in lamps whose
illuminating power is based upon the incandescence of a solid conductor, I form
such conductor within the lamp of a number of small beads or short tubes of
carbon, or a carbon compound, which I place upon a non-conducting rod difficult
Pin 1

page_text: of fusion, where they are free to slide with their ends or points in contact one with
another. The current is brought to this conductor by means of wire brushes
seperated to a distance from each other according to any desired length of luminous
line. Second, in lamps whose illuminating power is derived from quickly repeated
flashes of light, thereby combining the three principles of incandescence, flash, and are
to form a continuous and regular light capable of being maintained by a current of low
intensity. I effect this object by fixing a number of carbon rods at a short distance
apart from each other in a circle upon a base plate in circuit, and I sometimes
imbed the rods in an insulating substance. In the interior of this circle I place a
reflecting metal cone or disc, which is provided with one or more contact pieces or
rollers also in circuit. This centre is made to revolve on its axis by any convenient
means, and thereby each contact piece will form rapid make and break contact
with the point of each carbon in the circle. By this arrangement I am enabled to
make a large centre of light especially adapted for a head light to locomotives.
Another form of my lamps is for the use of carbon rods fed towards one
another, and consists in regulating their motion in proportion to consumption by
the deflection of a galvanometer needle, which by suitable well known mechanism
is made to act upon a brake wheel connected with them, thereby ensuring great
sensitiveness to give uniformity of light. In order to intensify the luminosity at
the focus I place a small reflector at the back so as to concentrate the rays passing
in that direction back into the arc. Fourth. My further improvement in lamps
consists in the use of discs of carbon or carbon compounds, and in placing two or
more of these near together, face to face, on the same axis, but seperated or insulated
from one another so that the current can only pass by an arc at the edges near to
which it is brought by suitable contact. Rotary motion is given to the discs by
any suitable means, the light practically always occupying the same point in space.
The discs may be formed of one piece, or they may be built up in sections, and
thus form a ring or margin of carbon, held together in a metal or other frame, and
I regulate the distance between the discs so as to secure and maintain the maximum
illuminating power according to the energy of the current. I sometimes arrange
the discs by placing a positive disc on each side of a central negative disc, and
work with a divided current or with independent currents, and thus produce a very
powerful light of great breadth, and with comparatively small resistence. In some
cases I use together one disc larger than another, so that the back or interior disc
serves as a reflector in the focus. I form a signal or coast light by using a compound
of sodium between the discs, by which the penetrating power of the light is greatly
increased. By means of suitable lenses and reflectors I concentrate the rays, and send
the beam vertical in flashes of differing degree for signaling purposes. Fifth. I con-
struct a standard lamp by placing the light in the base of the pillar, and by means of a
reflector below it project the rays upon another reflector at the top, by which the
light is diffused around.
For the diffusion of electric light, within interiors I concentrate the rays into a
channel of any suitable form or material, along which is one or more openings or
slots, through which a continuous stream of light is made to pass along its course,
and thus become diffused like day, with no shadows whatever.

page_text: DIECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Weightman Harrison in the Great Seal Patent Office on the
25th March 1880.
CHARLES WEIGHTMAN HARRISON, of No. 27, Southampton Buildings, in the
County of Middlesex, Gentleman. "IMPROVEMENTS IN ELECTRIC LIGHTING, AND:
IN THE MEANS OR APPARATUS EMPLOYED THEREIN."
"
This Invention relates to improvements in electric lighting, and in the means or
apparatus employed therein.
My Invention relates, firstly, to the manufacture of carbon electrodes or burners..
For this purpose I employ pure lamp black as a base, and mix therewith various
compounds, according to the kind of electrode required. For general purposes, as
for the production of the electric arc, I add to the lamp black, say, an equal part
by measure of wood pulp, which has been well dried and finely powdered, and
previously freed from impurities by suitable means, chemical and otherwise, as is
well known, or instead of wood pulp I add starch in similar proportions. I then
dissolve naphthaline, pitch, or resin in boiling tar, and maintain the mixture at a
temperature of about 250° Far. until the more volatile hydrocarbons have been
expelled and the whole has become plastic. I add sufficient of this compound whilst
still hot to the mixed powders above described, and knead or grind the whole
together so as to form a dry plastic mass which will cohere when pressed. I form
the negative electrodes for the production of incandescent and contact lights of
lamp black which has been impregnated with iron by immersion in a neutral
solution thereof, and this I mix with the plastic material above described, and thus
form when baked at a white heat a carbide of iron electrode or conductor. I place
the above compound whilst hot in metal moulds of any desired form, and by means
of powerful pressure or precussive force (by steam hammer or otherwise) I produce
a dense solid, which is ofterwards packed with powdered chalk in clay or other
suitable closed crucibles or trays, and then baked at a white heat for twenty four
hours (more or less) in an oven.
My improvements relate, secondly, to a current regulator or regulator for electric
lighting. This part of my Invention is illustrated at Figs. 1 & 2 of the accom-
panying Drawings, Fig. 1 being a plan, and Fig. 2 a vertical section taken at the
line a, b, Fig. 1. The base A of the instrument is formed of wood or some such
material, and has mounted upon it a metal box or case B for holding plates or
slabs C of graduated conductive and resisting power. These slabs C are formed
as segments of an annular plate, and are arranged radially around a central vertical
spindle D of metal. They are insulated from one another by plates H of glass or
other insulating material placed between them, and are held down in position in
box B by annular plate E, screwed onto the central uprising flange of box B.
Spindle D is insulated from box B by bush and washer F formed of some insulating
material, such for example as vulcanite. A contact tongue G formed of copper or
other conductive material is mounted on the vertical spindle D, with good con-
ductive connection. The current entering at H' passes by wire to spindle D, and
thence by tongue G to slab C, with which it is in contact, and so to box B and
away by terminal I; or the current may enter at terminal I and take exactly the
reverse course, the instrument being equally applicable to continuous and alternating
currents. Slabs C, C₁, to C¹º are formed with successively varying power of con-
ductivity and resistance one from the other. For example, supposing slab C to be of
the best conductive power, then each succeeding slab taken in the direction of the
arrow is made in a defined degree less conductive and more resistant till the last or
slab C is reached, which is nearly or quite a non conductor. According to the
"

page_text: current desired to pass through the instrument contact tongue G is turned onto one
or other of the slabs C, thus placing more or less resistance in the circuit, as desired.
For the composition of slabs C I mix in defined varying proportions a good con-
ductive with a resisting or non conductive material, such as lamp black or precipitated
or pulverised metal for one, and chalk or alumina for the other. I mould the
materials into slabs of the desired size, and form and bake them packed in closed
trays or crucibles. The instrument may assume other forms than that of a dial, as
shown, as for instance that of a parallelogram, in which case the slabs would
succeed one another in a line, and the contact tongue would be in form of a
Blide.
My improvements comprise also several forms of lamps. The first form is illus-
trated at Figs. 3, 4, 5, & 6 of the accompanying Drawings, Fig. 3 being a side
elevation partly in section on the centre line; Fig. 4 a front elevation also partly in
section at the centre line; Fig. 5 a plan; and Fig. 6 a sectional plan taken at c, d,
Fig. 3. The lamp, as shown, is designed for a constant current. A friction or break
wheel A has mounted on its spindle, and so as to turn with the wheel, two drums
B & C of different diameters, the larger B being double (or nearly so) that of the
smaller C. From drum B, and so that it may be wound thereon and unwound
therefrom, a flexible connector D (cord or chain) passes to the holder E of the
positive electrode, to which holder it is attached. This holder E, with its electrode
of carbon, descends by gravity, and so draws down cord D and gives motion to drum
B and break wheel A. To drum C is attached a cord F, so that whilst cord D is
being let out cord F is being wound onto drum C. This cord is attached to and
supports holder G and the negative electrode, so that the negative is raised at the
same time as the positive descends, and thus they approach each other; but as drum
B is of double (or nearly so) the diameter of drum C the positive advances at twice
the rate of the negative, and as this is about the relative rate of their consumption
the centre of light remains practically at one point in space. The holders E & G are
guided in their motions by rollers H, H, and I, the latter in each case being backed
up by a spring to keep the holders well up against rollers H, H, which rollers also
serve in the one case to convey the current to the holder E, and in the other to
take it away from holder G. If the descent of holder E were uncontrolled the
electrodes would continue to advance towards one another until they touched, and
they would then remain in contact; this is the case when the current is interrupted,
as when it is desired to put out the light. To separate the electrodes at the lighting
of the lamp the cord D, in its passage from drum B to holder E, is carried over a
pulley H attached to the armature of an electro-magnet I¹ placed in the circuit.
When the current passes through this electro-magnet the armature with pulley H
is attracted and cord D is drawn out, thus separating the electrodes and forming the
The electrodes are prevented again immediately approaching one another as
follows: The current which has formed the arc and is giving the light passes
through a coil J surrounding a magnetic needle K, which needle is deflected by the
passing current, and in its motion carries with it its spindle, on which is a break
block L, which is thus brought to bear against break wheel A and arrest its motion.
The electrodes are thus held stationary until by their consumption and the conse-
quent enlargement of the arc and increased resistance in the circuit the current
becomes weakened and the hold of the break block on wheel A lessened gra
dually, until the driving power (the weight of the descending electrode and holder)
overcomes the resistance of the break and the electrodes slowly advance until they
reach a point where the current, having gained sufficient renewed strength by reason
of the shortened arc, again exerts sufficient power on the break to arrest the motion
of the electrodes and maintain the arc at its desired length. By adjusting the break
block on its spindle in relation to the angle it bears to the needle the break block
may be made to act on the break wheel at any desired point of the needle's deflec
tion, and thus the strength and time of its action may be so delicately adjusted as
to render the motions of the electrodes almost imperceptible, and thereby maintain
arc.

page_text: the arc practically at one length, giving a steady, brilliant light. The form of lamp
described is arranged to be suspended, and three chains for this purpose are shown
on the top of the lamp. M is a globe of glass encircling the light. Fig. 7 shows a
similar lamp, but with slight modifications to adapt it for standing instead of being
suspended. The details are obvious from the Drawings. If it be deemed desirable
to compensate for the variation in the driving weight caused by the combustion of
the carbon it may be effected by making the drum slightly conical, so as to give the
shorter diameter when the weight is greatest and the longer diameter when the
weight has become lessened.
Another form of lamp constructed according to my Invention is illustrated at
Figs. 8 & 9 of the accompanying Drawings, Fig. 8 being a plan, and Fig. 9 a trans-
verse sectional elevation taken on the centre line of Fig. 8. In this lamp the
illuminating power is derived from rapidly repeated make and break contacts
causing flashes, and thus combining the three principles of incandescence, flash, and
arc, to form a continuous and regular light capable of being maintained by a
current of low intensity. I effect this object by fixing on a base plate A of copper,
or other conductor, and so as to make good contact therewith a number of carbon
or carbide of iron pencils or rods B a short distance apart, and in the form of a
circle; I also generally embed the pencils in an insulating or resisting substance C
such as plaster of Paris. Concentrically within the circle formed by; the pencils B
I place a conical mirror D, attached at its centre to a spindle E for support, and to
receive a rotary motion from it. The arms F supporting the mirror at the centre
and circumference diametrically are continued beyond the periphery of the mirror,
and form. two contact tongues F for giving the make and break contacts with the
ring of pencils B as the mirror and these contact tongues are rapidly revolved. At
their outer extremities these arms F are attached to and carry with them in their
revolution an annular mirror G to render more complete the reflection of the light.
A rapid rotary motion is given to spindle E, which carries with it in its rotation
mirrors D & G and arms F. The current is then let in through terminal H,
whence it passes through base plate A into the ring of pencils B, and as arms or
contact tongues F revolve a powerful spark or flash is made as each pencil is
brought in contact successively therewith. As illustrated, two of such arms or
contact tongues are shown, one of which is always in contact. More than two, or
any number desired, may be used. The current then passes by tongues F, spindle B,
bush H, and washer I, to terminal J. A sufficiently rapid rotary motion will
produce an apparently continuous ring of light of great brilliancy. As pencils B
wear away the contact tongues F are fed up to them by being continuously kept
up to their faces by spring weight, or other suitable means, applied to spindle E.
To allow of this motion a long feather on the spindle passes through a slot in
bush H, by which feather spindle D also receives its rotary motion from bush H
and pulley K. Any other means desired may be employed to impart the necessary
rotary motion. L is a plate of insulating material.
Another form of lamp is shown at Figs. 10 & 11 of the accompanying Drawings,
Fig. 10 being a face or plan view, and Fig. 11 a transverse section taken at the
line a, b, Fig. 10. In this form of lamp two discs or annular plates of carbon A
are fixed at the required distance from the opposite edges of a cylindrical ring of
carbon B. It is intended that the outer discs A should form the positive terminals,
though this may be reversed. A divided current, or two independent currents, are
brought to bear on discs A, through brushes C, and before the current passes the
two carbon pencils D have been pressed forward, each into contact with both a disc
A and the ring B. The points at which the brushes C impinge on discs A are as
nearly as possible opposite one another, and the currents entering the discs pass
directly through pencils D to ring B, and thence to spindle E, whence it passes
away, plates A being insulated from the spindle. The current entering through
brushes C passes also through coils F, which immediately attracting their arma-
tures draw away pencils D and form arcs on each side of ring B, between it and

page_text: annular plates A. A rotary motion is imparted by the spindle E to both annular
plates A and ring B, but as brushes C remain in one position, and as the current
takes the course offering least resistance it passes in the nearest line to ring B, and
thus the light remains always at one point in space. As shown, the annular plates
are made up of sections held in position by face plates and screws I, 1'.. Ring B
may also in like manner be made up in sections. Fig. 12 shows a lamp similar in
principle, but with only two annular plates A, and no intermediate ring B, the
current enters by one plate insulated from the spindle and passes away through
the other plate by the spindle. The space between the two plates forming the arc
may be filled with some nonconductive material (such as plaster of Paris) which is
dissipated during the consumption of the carbons, which in this case also have a
rotary motion imparted, to them, the point of light remaining practically in one
position. Fig. 13 shows a similar lamp, but with the back disc larger than the
front so as to act as a reflector.
Fig. 14 show a street lamp and lamp post arranged for an electric lamp to be
placed in the base, where it may be readily got at for trimming or other purpose,
and for reflecting the ray of such electric light upwards onto a reflector A. formed.
as an inverted cone, by which means the light is beautifully diffused. The lamp
post has within it a straight vertical tube B of polished metal, or glass, or other
reflecting medium, and the light being at its lower end has beneath it a parabolic
reflector C to collect all the rays of light. directed downwards and reflect them in
a vertical beam upwards onto reflector A.
Another part of my Invention relates to the diffusion of electric light within
buildings. This I accomplish by placing within the room or building a trough or
a tube having a slot extending along its length. Through this trough or tube I
throw a beam of light, and turn any portion of such beam through the open side
of the trough or slot in the tube where required by reflector, prism, or any other
suitable means. This causes a soft diffused light.
Having thus particularly described and ascertained, the nature of this my said
Invention, and the manner in which the same is to or may be performed, I claim
as my Invention, to be secured by the herein before in part recited Letters
Patent,-
1. The improvements in the manufacture of electrodes or burners, substantially
as herein before described.
2. The new or improved current regulator, substantially as hereinbefore
described, also as illustrated at Figs. 1 & 2 of the accompanying Drawings.
3. In lamps for electric lighting in which electrodes are fed towards one another
the combination of break wheel A, and drums B and C, substantially as herein-
before described, also as illustrated at Figs. 3 to 7 of the accompanying Drawings.
4. The combination in similar lamps of magnetic needle K, break block L, and
break wheel A, substantially as herein before described and illustrated at Figs. 3
to 7 of the accompanying Drawings.
5. The form of lamp illustrated at Figs. 8 & 9 of the accompanying Drawings,
also as herein before described.
6. The forms of lamps illustrated at Figs. 10 to 13 of the accompanying
Drawings, and hereinbefore described, whereby the centre of light is maintained
.practically at one point in space with disc lamps.
7. In disc and ring lamps forming the disc or annular plate and ring of sections
built up together, substantially as hereinbefore described, also as illustrated in the
accompanying Drawings.
8. In lamp posts for electric lighting the combination of reflector A, tube B, and
parabolic reflector C, substantially as hereinbefore described and illustrated in the
accompanying Drawings.
9. In the electric lighting of buildings, rooms, or confined spaces, diffusing the
light by throwing a beam along a trough or a tube having an aperture along its

page_text: |length, and turning any part of such beam through the open side of the trough or
the aperture in the tube as and where desired, substantially as hereinbefore set
forth and described.
In witness whereof, I, the said Charles Weightman Harrison, have hereunto
set my hand and seal, this Twenty fifth day of March, A.D. 1880..
CHAD. W. HARRISON. (LS.)