IMPROVEMENTS IN OR APPLICABLE TO ELECTRIC LIGHTING APPARATUS
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by Arthur Samuel Hickley at the Office
of the Commissioners of Patents on the 17th October 1878.
ARTHUR SAMUEL HICKLEY, of Kentish Town, in the County of Middlesex.
"IMPROVEMENTS IN OR APPLICABLE TO ELECTRIC LIGHTING APPARATUS."
This Invention consists of a stand having two or more glass or other non-con-
ducting supports fixed thereon, carrying at top a small table of vulcanite or other
suitable material. Through the centre of this table passes a rod or screw carrying
a small box, at bottom whereof is a metal cup, into which is fixed a block of com-
pressed magnesin, lime, chalk, or any other refractory substance capable of becoming
incandescent, and at the same time being a bad conductor of electricity.
Through the bottom of the stand project two metal rods side by side, but not
touching each other. Upon these rods are two springs tending to force them
upwards against the magnesia or other block. Upon the top of each rod is a clamp
suited to hold a carbon pencil or rod, which rods, when clamped, are in their turn
side by side, but not in contact nor cemented together. Each rod holding one
carbon is now connected to one pole of a powerful battery, dynamo-electric machine,
or other apparatus capable of giving a powerful current of electricity. The current
immediately passes up one carbon to the magnesia or other block, thence through
a piece of fine wire or foil (passed across the tops of the carbons) to the other carbon,
which becomes incandescent, destroying the above-named wire or foil and pro-
ducing what is known as the electric light.
As the carbons are consumed the springs push them upward against the block,
thus keeping the light steady, and in one position or nearly so. When the current
of electricity is variable and the light apt to be extinguished accidentally or
otherwise, the following arrangement is added or employed:-A small hole is drilled
through the magnesia or other block and its carrying cup, through which hole is
passed loosely a piece of platinum or other wire, carbon, or other conductor herein-
after called the connecting rod, upon the upper end of which is attached a piece of
soft iron.
Above this iron is an inverted electro-magnet, which is wound with a short
length of thick wire. The aforesaid platinum or carbon connecting rod connects

page_text: the two pencils by its own weight until the current of electricity which is made to
pass around the electro-magnet above it (which it does before passing into the first
carbon pencil) attracts the piece of soft iron attached to the top of the connecting
rod, thus drawing the said connecting rod away from and disconnecting the two
carbon pencils, when the points of these carbon rods or pencils will become incan-
descent and produce the electric light.
Should the light be extinguished or the current cease to flow, the electro-magnet
loses its magnetism, and the wire or carbon rod falls through the block and again
connects the two carbons, thereby completing the circuit and again producing the
light, the electro-magnet thus regaining its power once more, and automatically
withdraws the connecting rod from between the carbons.
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Or the magnet may be fitted with a moveable armature, which is dropped or
released on the current ceasing to flow, thereby completing the circuit of a current
of high tension, which " sparks between the tops of the carbon rods, the spark
acting as a bridge to convey the primary current from one carbon to the other,
which produces the light, whereupon the electro-magnet again attracts the armature,
shutting off the high tension current. Or the electro-magnet arrangement may be
entirely dispensed with, and the secondary current of an induction coil of a machine
giving a current of high tension may be allowed to flow constantly between the
tops of the carbon rods.
In another arrangement I use three carbons parallel to each other, the two outer
ones being negative, the inner one positive, or vice versa, each being kept against
the magnesium block by a spring as described for the first arrangement.