The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1879-12-21

o is the burner or incandoscent platinum IN the
shape Of bobbin supported within the vacuum
tube b. by Q rod b.. Of the same material as the
bobbin. The vacuum tube. b. Is sustained by the
case. h. and around said tube b. is glass globe !.
Within the case. X. is flexible metallic
nneroid chamber L that opens into the glass case
]. that the air. when expanded by heat can pass
into the aneroid chamber and give motion to the
flexible diaphragm. x. and parts connected there
with When the current circulating around the
bobbin. becomes too intense and heats the latter
too highly the air within the glass case. is ex-
panded and bulges downward by tho diaphragm. K.
and the pin thereon pressing upon the spring. 5.
and separating said spring from the block. G.
breaks the circuit to the burner The temperature
within the globe. /. lowers Immediately and the
parts return to their normal position. closing the
circuit through the burner to and g. This open
ing and closing Of the circuit is but momentary.
and. therefore, the uniform brancy of tho light is
not affected and there is danger Of the burner
becoming too highly heated.
PERPEcTINa THE MAcHrSEnY.
The lamp, after these latter improvements. was in
quite a satisfactory condition. and the inventor
contemplated with much qualification the near con-
ciuson of his labors. One by one he had overcome
the many difficulties that lay in his path. He had
brought up platinum substance for illumina-
ton from q state Of comparative worthlessness to
one well nigh perfection. lie had succeeded by
curious combination and improvement in air
pumps. in obtaining vacuum OF nearly one mill
ionth OF atmosphere, and he had perfected gen.
orator electricity producing machine flor all tho
time he had been working at lamps he was also ex-
perimenting in magneto-electric machnes that gave
out ninety per cent in electricity OF the energy
it received from tue driving engine. In a word. all
the serious obstacles toward tho success of incan
halt. hal palta al
away, and there remained but comparatively few
minor details to be arranged before his laboratory
was DO thrown open for public inspection and the
light given to the world for better or for worse.
GREAT DISCOVERY.
There occurred, however. at this juncturc dis
covery that materially changed the system and gave
rapid stride toward the perfect electric lamp. Sit
ting one night in his laboratory rejecting some
of the unfinished details Edison began abstr accdly
rolling between his fingers piece Of compressed
lampblack mixed with tar for use in his telephone.
For several minutes his thoughts continued far
away, his fingers in the meantime mechanically
rolling out the little piece OF Grred lampback until
il had become a slender hancnt Happening to
glance il tho idea occurred to him that it might
give good result as burner ii made incandescent.
few min utes later the experiment tried. and.
to the inventors qualification, satisfactory. although
not surprising results were obtained. Furthe
pcrments were made. with altered forms and COM
position OF the substance. each experiment demon
stratng that last the inventor upon the right
track.
COTTON THREAD.
A spool OF cotton thread lay ON the table in tho
laboratory The inventor OF small piece put it
ia q groove between two clamps of iron aud placed
the latter in the furnace The satisfactory light OBJ
tanned from the taired lam pback had convinced him
that nlaments Of carbon OF texture not previously
used In electric lighting were the hidden agents to
make u thorough success of incandcscnnt lighting.
and 1t with tnis view that he sought to test the
carbon remains of n cotton thread. At the expra-
ton OF an hour he removed the iron mould contain
ing the thread from the furnace and took out the
delicate carbon framework of tho thrsad--all that
was left OF IL after it's fiery ordeal. This slender
ilament he placed In globe and connected it with
electric current Then ho extracted the air from tho
globe and turned on the electricity
Prcstoi q beautiful light greeted his eyes. He
turns on moro current expecting the fragile hament
instantly to fuse; but no. the only change is
brilliant light. He turns more current and still
more but tho delicate thread remains entire Then.
with characteristic impetuosity and wondering and
marvclling at tho strength or the little hamen he
turns on the full power of his machine and eagerly
watches the consequence. For minute
the tender thread to struggle with the intense
diamond itself-thcn at last IL succumbs and all
darkness. Tho powerful current had broken 1t In