Dodge City times. [volume] (Dodge City, Kan.) 1876-1892, 1880-10-23
Edison's Story Of the Electric Light


THE editor Of the North american Re
ciew has induced Mr.. Edison to "tell
his own tale in his own melodious way"
and the result is an interesting article
over his signature, which appears in
the October number of that periodical.
Mr.. Edison begins his article with a
few words to those who have expressed
their Impotence at the delays in the
perfecting of the electric light The
delays which have occurred to defer its
general introduction are chargeable, he
says, not to any defects since discovered
in the original theory Of the system in
its practical workings, but to the enor-
nous mass of details which have to be
mastered before the system can 90 into
operation on a large scale and on a
commercial basis as a rival of the exist
ing system of lighting by gas. Impor-
tant improvements have been brought
about by these delays in the direction
of economy and simpification at almost
every point in the system, as well as in
the details of manufacturing the appa-
raJus.
The lamp, the inventor tells us, has
been completely transformed. To quote
his words:
1.-The perfect lamp consists of an
oval bulb of glass about hve inches in
height, pointed at one end, and with a
short stem, three-quarters of an inch
in diameter at the other. Two wires of
platinum enter the bulb through the
stem. supporting the loop or l-shaped
thread OF carbon, which is about two
inches in height. The stem is her.
metically sealed after the introduction
of the carbon loop. At its pointed end
the bulb terminates in an open tube
through which the air in the bulb is ex-
hausted by means of mercury pump
till not over one-millionth part remains.
The tube is then closed. The outer ex-
tremiiies of the two platinum wires
are connected with the wire of an
electric circuit, aud at the base of the
lamp is screw by which the circuit is
made or broken at pleasure. When the
circuit is made the resistance offered to
the passage of the electric current by
carbon causes the loop to acquire a
high temperature and to become in
candescent, but as this takes place in a
vacuum, the carbon is not consumed. The
life" of carbon loop through which
a current is passed continuously varies
from seven hundred and fifty to nine
hundred hours. With an intermitted
current the loop has an equal duration
of life, and as the average time AL
artificial light is used is five hours per
day, ii follows that one lamp will last
about six months. Each lamp costs
about fifty cents. and when one fails
another may be easily substituted for
it"
Another important modification of
the system, introduced since the last
authorized account of the light was
published, is the substitution of dynamo
machines for magneto-machines in the
stations from which the electricity is to
be supplied to the several districts of
city-a change in the direction of sim
plicity and economy. To the question
which is SO often asked, when will a
public demonstration of the working of
the system 5e made, the inventor re-
plies:
THAT such demonstration will in
all probability be made at MEMO Park
within two months from this date. The
time which has ELAPSED since the pre-