The new North-west. [volume] (Deer Lodge, Mont.) 1869-1897, 1880-10-01
The Success Of the Electric Light
Thomas A. Edison In North American he''e" 'o'
Drtnher.

Thomas A. kdis0r III MUM A'"S''N"'
October.
Not o little impotence has been mani
tested by the public at the seemingly unac-
countable hardness with which the work
OF introducing the carbon-loop " electric
lamp into general use has hitherto pro-
crossed. IL is now several months since
the announcement was made through the
newspapers tina. all the obstacles in the
way of the utilization OF the electric light
M n convenient and economical substitute
foa gaslight had been removed that
method had been invented by which cleo
tricity for light or power could be convey
cd to considerable distances economically
that the current could be divided almost
dd infnttuga, and that the electric lamp was
henceforth to be as manageable for house
hold purposes as gas jet. But, SO far as
the public can see, the project since that
time has made no appreciable advance to-
ward realization. The newspapers have
reported, on the whole with very fair de-
gree of accuracy, the results OF the expert
ments made with this system Of lighting at
Menlo Park !; scientific experts have pub
lished their Judgments some of them pro-
nouncing this system to be the desiderated
practical solution of the problem of cleo
trio lighting which has vexed the minds of
physicists since the day when Sir Hum
phrey Davy produced his famous five-inch
yoltaic arc. Still it must be confessed that
hitherto the weight of scientific opinion
has inclined decidedly toward declaring
the system failure, an impracticability
and based on fallacies. 1r will be deemed
discourteous If we remind these critics
that scientific men Of equal eminence pro-
nounced ocean steam navigation, subma-
rine telegraphy and duplex telegraphy inn
possibilities down to the day when they
were demonstrated to be facts. Under the
circumstances it was very natural that the
unscientiic public should begin to ask
whether they had not been imposed upon
by the inventor himself or hoaxed by un .
scrupulous newspaper reporters.
Now, the fact is that this system of cleo
trical lighting was from the arst all that 1t
was originally claimed to be-namely, a
practical solution of the problem of adapt
ing the electric light to general uses and of
making it an economical substitute for gas
light. The delays which have occurred to
defer lis general introduction are chargea-
BILE, not to any defects since discovered in
the original theory of the system or in its
practical working, but to tho enormous
mass of details which have TO be mastered
before the system can 60 into operation on
large scale, and on q commercial basis as
rival of the existing system of lighting
by gas.
With the lamp and generator which at
the time of the first announcement 1t was
proposed to use, the electric light could
have been made available for all illumina-
ting purposes as gas is now the expense
would have been considerably less with the
electric hight the lamp would have been
quite as manageable as gas-burner. But
fortunately the unavoidable delay inter-
posed by administrative and economic con-
siderations afforded opportunity for further
research and experiment, and the result
has been TO introduce many essential modi-
fications at both ends Of the system-both
In the generator and IN the lamp; at the
same time sundry important changes, all in
the direction Of economy and simplifcation,
have been made at almost every point In
the system, as we'll as in the details of man
ufacturing the apparatus.
As for the lamp, 1t has been completely
transformed. The external form Of the
two types of lamps is identical the prin-
ciple of Observation-Disclosures Of .
solid body In pdcuo-is' also the same but
in the earlier lamp light was produced BY
the incandescence of q platinum wire wound
on spool OF zircon in the perfected lamp
the source OF light is incandescent carbon.
Another essential difference between the
two Is found in the form given to the incan-
descent body in the platinum lamp 1t was
coiled compactly on q small spool in the
carbon lamp 1t Is q loop some five inch
es in total length. This incandscent loop
is found iu practice to afford better light
for domestic purposes than an incandescent
mass of compact form; the shadows II
casts are not SO sharply defined, their edges
being softened.
This loop of carbon is now prepared
from the fiber of cultivated species Of
bamboo from Japan. A thread Of this ma.
terial, after undergoing a certain chemical
process, is bent into the required shape
and then reduced to carbon. The resulting
carbon loop is ola remarkably HOMOGENEOUS
structure, aud possessed Of high degree
The perfected lamp consists of an ova
bulb Of glass about five inches In height
pointed at one end, and with short stem
three-quarters Of an inch In diameter at the
other. Two wires OF platinum enter the
bulb through this stem, supporting thu
the loop or fl-shaped thread of carbon
which Is about two inches In height. The
5 stem is Theoretically sealed after the intro.
duction of the carbon loop. At its pointed
end the bulb terminates In an open tube
through which the DIR in the bulb Is ex-
bausted by means of of mercury puma
till not over one millionth part remains
the tube is then closed. The outer extrem
titles 1i the two platinum wires are connect
ed with the wires of an electric circuit, AND
at the base Of the lamp is screw by which
the circuit is made or broken at pleasure
Whsn the circuit Is made, the resist
ancc offered to the passage Of the electric
current by the carbon causes the loop Il
acquire high temperature and to become
incandescent but as this takes place in I
vacuum, the carbon 10 not consumed TIL,
"life Of carbon loop through which |
current Is passed continuously varies from
seven hundred and fifty to nine hundre,
hours. With an intermitted current, tb
loop has an equal duration Of life; and, a
the time an artificial light Is used IL fiv
hours per day, II follows that one lamp viii
last about six months. Each lamp cost
about fifty cents, and when one fails anothe
may easily be substituted for it
The light is designed to serve precisel