The Cheyenne daily leader. [volume] (Cheyenne, Wyo.) 1870-1884, 1879-12-28
ELECTRIC LIGHT.
ILLUSTRATION OF THE LAMP.
How Prof. Edison Discovered the
Properties of Carbon-HIsto-
~ II the Perfect Elec-
trfc Light.

trio Light.
The lamp, after many improve
ments, was in quite a satisfactory con
dition, and the inventor contemplated
with much qualification the near con-
cluson of his labors. One by one he
had overcome the many difficulties that
lay in his path. He had brought up
platinum as substance for Illumination
from a state of comparative worthless
ness to one we'll nigh perfection. He
had succeeded, by a curious combina-
tion and improvement in air pumps, in
obtaining a vacuum of nearly one-mil-
lionth of an atmosphere, and he had
perfected n generator, or electricity
producing a machine flor all the time he
had been working az lamps he was
also experimenting in magneto-electric
machines) that gave out some 80 per
cent. in electricity of the energy it re-
ceived from the driving engine. In a
word, all the serious obstacles toward
the success Of incandescent electric
lighting he believed had melted away,
and there remained but q comparatively
few minor details to be arranged before
his aboratory was to be thrown open for
public inspection, and the light given to
the world for better or for worse. There
occurred, however, at this juncture a
discovery that materially changed the
system and gave Il rapid stride toward
the perfect electric lamp. Sitting one
night in his laboratory, rejecting on
some of the unfinished details, Edison
began abstractedly rolling between his
fingers a piece of compressed lamp black
mixed with tar, for use in his telephone.
For several minutes his thoughts con-
tinuel far away, his fingers, in the
meantime, mechanically rolling out tn e
little piece of tarred lampblack until it
had become a slender filament. Hap
pening to glance at il, the idea occurred
to him that it might give good results
as a burner if made incandescent. A
few minutes later the experiment was
tried, and to the inventors qualification,
satisfactory, although not surprising
results were obtained. Further expert
ments were made with other forms and
compositions of the substance, each ex-
pertinent demonstrating that at last the
inventor was upon the right trac k. A
spool of cotton thread lay on the table
in the laboratory. The inventor cut off
a small piece, put in a groove between
two clamps of iron and placed the latter
in the furnace. The satisfactory light
obtained from the tarred lampblack
had convinced him that flamentS of
carbon of a texture not previously used
in electric lighting were the hidden
agents to make a thorough success of
incandescent lighting, and it was with
this view that he sought to test the car
bon remains of Il cotton thread. AT
the expiration of an hour he removed
the iron mold containing the thread
from the furnace and took out the deli
cate carbon framework of the thread
all that was left of it after its fiery or
deal. This slender filament lie placed
in a globe, and connected it with the
wires leading to the machine generating
the electric current. Then he extracted
the air from the globe and turned on
the electricity.
EUREKA.
Prestol a beautiful light greeted his
eyes. He turns on more current, ex-
pecting the fragile llament instantly to
fuse. But no !; the only change is a
more brilliant light. He turns or more
current, and still more, but the delicate
thread remains the same. Then, with
characteristic impetuosity, and wonder
ing and marveling at the strength of
the little flament, he turns on the full
power of his machine, and eagerly
watches the consequence. For a min
ute or more the tender thread seems to
struggle with the intense heat passing
through it-heat that would melt the
diamond itself. Then at last it suc-
cumbs and all is darkness. The power
full current had broken it in twain, but
not before it had emitted n light of sew
eral gas jets Eagerly the inventor has
tened to examine under the microscope
this curious flament, apparently so deli
cute, but in reality much more infusi-
BILE than platinum, so long considered
one of the most infusible of metals.
The microscope showed the surface of
the filament to be highly polished, and
its parts interviewer with each other.
1t was also noticed that the flament
had attained a remarkable degree of
hardness compared with its fragile
character before it was subjected to the
action of the current. Night and day,
with scarcely rest enough to eat a hasty
meal or catch Il brief repose, the in
ventor kept up his experiments, and
from c%arbonizing pieces of thread he
went to splinters of wood, straw, paper,
and many other substances never before
used for that purpose. The results of
his experiments showed that the sub
stance best adapted for carbonization
and the giving out of incandescent light
was paper. preferably thick like card