The Stourbridge Observer, Cradley Heath, Halesowen & District Chronicle.
Stourbridge, West Midlands, England, 1880-01-10 00:00:00

THE ELECTRIC LIGHT.
(From Monday's TimeB).

The last American mail has brought us interesting
details relating to the progress made in manipulating
the electric light Pending the researches in which
Professor Edison has for a long period been engaged,
it appears that his laboratory at Menlo-park was prac-
+;....ll, an ahranactra nntil thit gonna ani.ntiat
should have arrived at a point to enable him to declare
that complete success had attended his final efforts.
That point has apparently been reached, inasmuch as
Mr. Edison has now published, through the columns
of the NEW York Herald, an elaborate and detailed
account of his labours.
The various phases of experiments were coupled
with numerous disappointments, and his labours
furnish evidence of an inexhaustible store of patience
and perseverance. Minutely describing the course of
his studies, Mr. Edison says that he has made the
discovery that the carbon framework of a small piece
of paper is the best substance for incandescent light-
ing. Thick paper is preferable: thin, however.
giving good results. The steadiness, reliability, and
non-infusibility of the carbon filament, Mr. Edison tells
us, are not the only elements incident to the new
discovery. There is likewise obtained an element of
proper and uniform resistance to the passage of the
electric current. To obtain that desideratum has been
the cause of most anxious inquiry and of incessant
labour, for without it absolute success in electric
incandescent light is not attainable, the presence of
all other neoessary properties, even in the fullest
degree, notwithstanding.
Apiece of cardboard, known In the trade as
"Bristol," is cut, with a suitable punch, into stripe in
the form of miniature horseshoes, about 2 in. long and
one eighth wide. A number of these strips are placed
in a wrought-iron mould, separated from each other
by tissue paper. The mould, after being well covered,
is placed in an oven, where it is gradually exposed
to a temperature of about GOO degrees Fahrenheit, so
as to allow the volatile portions of the paper to pass
away. The mould is then removed to a furnace,
kept there till it attains almost a white heat, and
subsequently allowed gradually to cool down. On open-
ing the mould, the charred remains of the cardboard must
be taken out with great care, in order to prevent
them from falling to pieces. They are placed in a
small globe and attached to the wires connecting the
generating machine. The next thing is to extract the
air, by means of the pump, from the globe; that
being accomplished, the globe is sealed, and the lamp
is ready for use. It should be observed that the new
lamp requires no complex regulating apparatus, such
as characterized the earlier efforts. In fact, Mr.
Edison finds that all previous labour in regard to re-
gulatore was practically wasted, and furthermore, that
electricity can be regulated with absolute re-
liability in a manner precisely similar to that in which
the pressure of gas is now produced._
_

The system now adopted by Mr. Edison in connect-
ing the wires admits of a given number of lights being
extinguished without affecting those of other burners.
In the same way as we would shut a certain number of
gas burners and permit others to draw a supply from
the meter the electric light can be obtained or shut out.
The wires leading to the generating machine may be
run through ordinary existing gas-pipes to a central
station at a distance of, say, half a mile. The only
change really necessary in the present arrangements
would apparently consist in unscrewing the gas-jet and
replacing it with an electric lamp of Mr. Edison's con-
struction. The probabilities are that for the purpose
of lighting a city it will be necessary to establish a
given number of stations, these stations to be distri-
buted in such a manner that each of them could .eined7
a district covering an area of about one half or third of
a mile. At each station there would be one or two
engines of great power to drive generating machines,
each capable of feeding 59 lamps.
From the description now given it appears that the
apparatus primarily used by Mr. Edison was in the
shape of a large tuning-fork, constructed in a manner
that both ends would vibrate when placed near the
poles of the great magnet. Experience has demon-
atrated the impracticability of that apparatus, and it
became necessary to search for other mean?. One
experiment was made after another, which had the
tendency to lead gradually to the adoption of the
system now employed in the generating machine, and
which Mr. Edison terms the Faradaic machine. It is
briefly described thus :—Two upright iron columns, 3ft,
in height and Bin, in diameter, covered with coarse wire
and resting upon a base, form the magnetic poles.
Fixed on an angle, so as to admit a free revolution
between the poles, is a cylindrical armature of wood,
wound parallel to its axes with fine iron wire. This
cylinder is made to revolve rapidly between the mag-
netic poles, and by means of a belt, driven by an
engine, strong currents of electricity are generated in
the wire surrounding the armature, and these currents
are carried along the wires to the electric lamp.
In addition to the uses for lighting, the electric
muter is capable of performing other work, such, for
instance, as running sewing machines, It rcquires no
more electricity than is necessary to give out one
electric light of the strength of a common gas jet.
There are other uses for the motor' which, however,
involve a technical knowledge of the laws of electricity,
The mode of measuring the electricity used by each
householder is exceedingly simple. An electrolytic
cell and a small coil of wire are placed in a box of
about half the size of a common gas meter, and kept
in a convenient corner, similar to where the meter is
placed at present, The measurement is obtained by
collecting, on small plates, the copper particles which
deposit in the electrolytic cell, such deposit being
caused by the electric current passing through tho cell,
At given periods—say once a month—these deposits
are weighed, and by a simple rule of calculation the
amount of electricity consumed is ascertained.
Mr. Edison felt convinced some time ago that all
serious obstacles towards stlCCess in obtaining mean.
descent electric lighting had been overcome; but the
Present discovery has tended to materially change the
system in perfecting the electric lamp. Platinuna had
been brought up as a substance for illuminating power
from a state of comparative worthlessnesrato one well
nigh perfection. Improvements had been obtained in
SIX pump., obtaining a vacuum of nearly one millionth
of an atmosphere, The magnetcheleotrio machine

had been perfected so as to give out some 90
per cent., in electricity, of the energy it received
from the driving engine. Accidentally, Mr. Edison
was induced to test the carbon remains of cotton
thread. Placing the slender filament in a globe, and
connecting it with the wires leading to the generating
machine, the Professor was gratified by the production
of a beautiful light. Turning on a stronger and
stronger current, the tender thread remained entire,
till, finally, the maximum power of the machine was
turned on. For a micute or two the tender thread
seemed to struggle with the intense heat—heat that
would melt a diamond—till at last it succumbed, and all
was darkness. The powerful current had broken it, but
not before it had emitted a light equal to that of several
gas jets. Examined under a microscope the curious
filament, apparently so delicate, proved in reality
more infusible than platinum, so long considered one
of the most infusible of metals. Mr. Edison kept up
his experiments; from carbonizing pieces of thread, he
turned to splinters of wood, straw, paper, and many
other substances never used before for the purpose.
The results have had the tendency to show, as stated
above, that the substance best adapted for carboniza-
tion and the giving out of an incandescent light has
proved to be paper.

A telegram from The Times Correspondent at Phila-
delphia, dated Jan. 4, says :

" Mr. Edison's carbon horseshoe electric lamps
continued successfully burning on Saturday night at
Menlo-park. There were about 100 in position, which
were supplied by two generators. Menlo•park was so
overrun with visitors and investigators last week that
the manufacturer of the lamps was impeded. Scien-
tific criticism of the success of Mr. Edison's invention
has almost ceased in the United States, the public
generally regarding the invention as successful."