Barbour County index. [volume] (Medicine Lodge, Kan.) 1880-current, 1888-03-21
ELECTRIC LIGHTS
How They Are Made in an Indian
apolis Establishpent.
Strange Processes by which the Great
Modern Illuminating Machinery Is
Produced-How the Electric Current
Enters the Incandescont Globes.

70 produce aud distribute electric light, fs
the latest evolution OF science and in
ventive genius, and one of the largest es-
adjustments employed in that work is in
indianapolis.
Much of the work in the construction Of
an electric-light apparatus is not greatly
different from other work In metals. The
combinations produce vastly different re-
suits, TO be sure, but the casting, and
hammering, and fling, and drilling 80 on
alike in making a dynamo or ssroller-
MILL" The curious features are not many,
but they are so wholly different from any
other work in mill or factory that short
account of them may not be without in
terest to good many readers. There were
three particularly noted by an Indianap-
oils Journal reporter. who recently ac-
companied the secretary, Mr.. Rorison,
through the works at the south end of the
Nordyke & Marmon mill works. Here
one hundred and seventy five hands are
employed, and more are needed. Plants
have been sent to nine cities in California
and four in Texas, making in all
twenty carloads of twenty tons each, or
near it, and orders run constantly ahead
of their ability to meet them. The three
especially attractive features noted were,
first, the testing of the arc lights; second,
making vacuums in the little glass globes
for incandescent lights, and third, testing
the completeness of the vacuum and the
consequent efficiency or failure of the
light.
In testing the arc light number of the
open globe lamps, with automatically-
regulated carbons, are hung up toget thor
| in the restroom and connected with a
wire running to dynamo In the work.
shop below, which operates all tho arc
lights of West Indianapolis. The intensity
of the light of each is there examined, and
the efficiency Of the apparatus moving
the carbons. The arc light is usually
equal to 1000 candles, but this intensity
can be doubled by drawing the carbons
slightly further apart. When so close to-
gether as seemingly to touch, the light is
an intensely bright white spot without
glitter or rays, and without any
painful effect on the eyes. A hairs
breadth of greater separat tion shoots
out dazzling brilliance that the
eye can not bear when the ground glass
globe is removed. Another hairs breadth
or separation makes a miniature sun with
binding rays darting out in thousand
directions, and filling the air all about with
binding scintillations that might for in
tensity be scales Knocked from the sun by
one OF the comets that some philosophers
believe make solar heat and light by their
collision. Yet all this amazing light.
equaling 1900 to 1000, or 5000 candles, is
produced by spark not larger, appar-
emily, than the burning coal on the end of
match, rising from the bubbling surface
OF the lower carbon, which the intense
heat fuses, scoops into minute hollows
and keeps incessantly boiling, like a
microscopic eruption of an infinitesimal
volcano. Nothing of this can be discerned
through the ground glass globe that conn
monty covers the arc light.
The incandescent light for domestic or
industrial use must be prod uced in a
vacuum. A perfect one is, of course. i'm
possible. Not because mature abhors a
Vacuum" as the old scholiasts and
alchemists asserted, but because human
| ingenuity has not hit upon any plan to
make it. But a practically complete one
is made Tor the electric incandescent
lignt, as 1t is made in the mercurial ther-
mometer, "the Torrecillian." as il ia
called. Both sides of small room are
set as high as the facs of an average
man with cases to which are attached a
series of glass globes of an oval form. al
ternating with the elongated little globes
or the electric light and all are connected
oy pipes controlled by stop.cocks. The
larger obes,holdfng quart apparently,
are filled with mercury, which can be
passed from them to the light globes.
whence the metal expels the air as il fills
them. Glass tubes in the necks of the lit
tie pecan-shaped globes show the air bub
bles passing up through the mercury
there, and the manager of this DEPART
ment says 1t takes about five hours to
make sure of as complete an exclusion of
the air as is practicable to the agencies
so far devised. When the vacuum is COM
fhA IL nl. Z. I.
closed, and is ready for the test.
The electric current en.e the In
candescent globe through two minute
filaments hardly larger than a hair. n III.
tie less shan an inch long, standing
parallel, and half an inch or more apart
These filaments are, the inventor
says, as nearly pure carbon, short of
diamond making, as chemical skill and
mechanical ingenuity can get at it. The
globes, exhausted of air and ready for
testing, are hung on little cross arms re-
volving on the tops of slender supports as
high as mans head, through which the
electric current is passed A row of a
half dozen OF more OF these surmounts the
vacuum apparatus ON each side Of the
| room. The first appearance of the current
In the globe is faint, hair line of red
light, in the form of an elongated horse-
shoe, barely perceptible to the keenest in
spection. Then the red deepens and
widens, and puts off a purple or violet
tint that seems TO accompany the first
show of light. Next the red ligbtens to a
whittier color, and the horseshoe grows
still broader and brighter. Finally its
light is pure white, steady and brilliant,
but not dazzling. Then the test is COM
piete and the globe is ready for use.
About two thousand pounds of mere curry
are required for evacuating one full set of
incandescent globes, and, as there is no
consumption and worry little waste in this
use of it, the amount required for one
days work will serve forevery day of the
year, and dozen years.