The Red Cloud chief., 1880-11-25

VIC October numbecW that periodical
Mr.. Ellison begias his article with a
lew words TO those who have expressed
their impatience at the delays in the
perfecting of the electric light The
DELAYS which have occurred 70 defer its
general introduction are chargeablc. he
says. not To any defects since discovered
in the original theory Of the system in
its practical workings, but to the enor-
mass Of details which have To- be
mastered before the system can go into
operation on q large scale and on a
commercial basis As a rival Of the exist
ing system Of lighting by gas. lmpor-
tant improvements have been brought
about by these delays in the direction
Of economy and simplification ut almost
every point in the system, as well Is in
the details Of manufacturing the appa-
ratus.
The lamp, the inventor tells US, has
been completely transformed. To quote
his words:
THE perfect lamp consists of an
oval bulb of glass about hve inches in
height. pointed at n end, and with a
short stem, three-quarter5 Of an inch
in diameter at the other. Two wires Of
platinum enter the bulb through the
stem, supporting the loop or n-shaped
thread of carbon, which is about two
inches in height. The stem is her
medically sealed after the introduction
of the carbon loop. AT its pointed end
the Sab terminates IN an open tube
through which the air i'm the bulb is ex-
haustcd by means of a mercury pump
till not over one-millionth part remains.
The tube is then closed. The outer ex-
tremities of the two platinum wires
arc cOnnected with the wire OF an
electric circuit, and at the base of the
lamp is n 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
candesccnt, but rs this takes place in n
vacuum the carbon is not consumed. The
life" of q carbon loop through which
a current is passed continuously varies
from seven hundred and fifty TO nine
hundred hours. With an intcrmitted
current the loop has an equal duration
of life. and as the average time an
artificial light is used is five hours per
day, it follows that n lamp will last
about six months. Each lamp costs
about fifty cents, and when n fails
another may be easily substituted for
IT,"
Another important modification of
the system, introduced since the last
authorized account of the light was
--ll:lol -. ,lttt.~, - l,n NJ
machines for magnetO-machines in the
stations from which the electricity is to
be supplied to the several districts of a
city-a change in the direction of sim
plicity and economy. TO the question
which is SO often asked, when will n
public demonstration of the working of
the system be made, the inventor re-
plies:
THAT such q demonstration will in
all probability be made at MenlO Park
within two months from this date. The
time which has elapsed since the pre-
liminary demonstration of last January
has been by no means n season of mac
ton for the promoters of this enterprise.
There is a vast gulf between the most
successful laboratory experiment posi-
Bile and the rehabilitation of the results
of that experiment in a commercial
sense. "A EprpdiSous amount of work
was necessitated by the establishment
of factories for producing the lamps.
the generators and other essential parts
of the system in large quantities, so as
to be able to supply the first demand"
Mr.. Edison goes into the particulars
concerning his lamp, giving a state
ment of its advantages over gas in the
matter of simplicity in the management
and economy. He repeats what has al
ready been stated in the Herald cOn
corning the plans for lighting the cities.
Estimates are being made of the exact
cost of plant" in the different cities;
contracts are being negotiated for the
dynamos, lamps, wire and all the other
supplies needed for the practical intro
duction of the system throughout the
country.--NeW York Herald.