IMPROVEMENTS IN OBTAINING LIGHT BY ELECTRICITY, AND IN THE MEANS OR APPARATUS EMPLOYED THEREIN
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by Charles Weightman Harrison at the
Office of the Commissioners of Patents on the 28th October 1878.
CHARLES WEIGHTMAN HARRISON, of South Kensington, in the County of
Middlesex, Gentleman. "IMPROVEMENTS IN OBTAINING LIGHT BY ELECTRICITY, AND
IN THE MEANS OR APPARATUS EMPLOYED THEREIN.”
This Invention consists in the first place in doing away with the ordinary form
of electrodes or burners, and in forming that part of an electric circuit where the
light is to be obtained of a fluid or temporary conductor, and in varying or
breaking its conductivity by vibratory motion or other suitable means for causing
the production of sparks or flashes sufficiently rapid to produce the effect of a
continuous and uniform light. A convenient arrangement by which I carry this
part of my Invention into operation consists in the construction and use of a candle
holder made of earthenware or other suitable material, the upright or stick of
which is formed of three insulated tubes fixed in line side by side, the two outer
tubes being filled by the fluid conductor, and being by suitable connections kept
supplied from elevated sources, and from which tubes the fluid passes through an
outlet near the top on to a properly fitted movable piston or body at the top of the
inner tube. This piston or body is caused to vibrate by connection with an
adjustable armature fixed underneath the candle holder. By this means a series of
continuous sparks or flashes are produced. I prefer to use as the conductor
mercury or a compound of mercury with potassium and sodium, or other metals
or elementary bodies which constitute the solar spectrum as referred to in a
Provisional Specification lodged by me on the 2nd September 1878, No. 3470.
I confine the vapours given off by the light under a bell glass or other cover, which
fits air-tight into a groove or rim around the edge of the candle holder. The
vapours are conducted away through a hole in the base by a pipe leading to a
suitable condenser in the form of an iron bottle or otherwise. I surround the
candle with its bell glass in a globe of ground glass or other suitable material in
order to diffuse the light, or where it is desired to reflect and concentrate the light
for locomotives; or for signalling or other purposes I fit a reflector in proper position.
Din 171

page_text: Sometimes I form a group of several lights in a single lamp by the simultaneous or
varied interruptions or breaks in different parts of the circuit or in several circuits
brought within the lamp, and these several lights may be placed around or at
opposite sides of a circular or other suitable reflector; in this case the supply of the
fluid conductor to the lights may conveniently be led through the interior of the
reflector, and the vapors be led down-a-post-or-otherwise to a condenser.
By the means above described I am enabled to dispense with the use of a steam
engine and large dynamo-electric apparatus, and to obtain light in a simpler and
more economical manner. For instance, a small dynamo-electric apparatus may be
worked by a spring or descending weight to give the inductive current, or the
current may be generated by-a-galvanic, voltaic, or thermo-electric battery, and be
conveyed either direct to the lamp or lamps, or through a coil or coils, and-with-or-
without condensers. Electric light may thus be rendered available for domestic
purposes.
In order to generate a current of thermo-electricity, I sometimes make use of the
heat of an ordinary stove or fire-place to operate a thermo-electric battery as will
be well understood, the electric current being conveyed from the battery to the
lamp.