The Rock Island Argus. (Rock Island, Ill.) 1877-1885, 1881-05-10
EDISON'S LIGHT.
The non-electric Illuminator
and it's success.
A Letter from Professor Carhart CT
Northwestern University.
Special correspondenee Of The Eyening journal

y,
favored last evening with admission to Mr.
1 Edisons private office at the headquarters
of the Edison Electric Light Company, on
p Fifth avenue. The purposes of this COM
pany are sufficiently well known. 1t has
now local habitatiOn in an elegant Fifth
avenue mansion, brilliantly Illuminated
every evening as an announcement of Edi-
sons apparent success in domestic lighting
by electricity.
AS we were about sending up our cards
Mr. Edison entered the vestibuIe, and con
Quoted us directly to his office. The room
was dark when we entered, but a quarter
turn of hard rubber key almost instantly
filled it with midday brightness. There
was no adjustment of the key no flicker
ing of a gas flame no disagreeable and de
leteriOus products of combustion, but the
steady glow of lamp of sixteen-candle
power. This particular lamp depended
from Il curved brass tube attached to the
top of large double cylinder desk Over
the pear-shaped bulb was suspended a
white glass shade which reflected the light
down upon the accumulated business pa
pers on the desk. In the upper hall an un-
covered lamp was attached to an ordinary
gas bracket, while a chandelier of four
electric lights surmounted the newell post
in the main hall below.
no reference to gas illumination, but dis
cussed the ultra gaseous state of matter"
which was my topic for experimentation in
| Cooper Union the following evening, and
then kindly cleared up several points in the
construction and practical working of his
lamps, about which l had been in doubt
| These lamps are now exhausted to about
millionth of an atmosphere, so that the con
sumption Of the carbon conductor by com
bustion may be entirely disregarded These
latest lamps are constructed of a carbonized
fiber of bamboo. A piece six inches long
cut between joints, is pared up into thin
slices; then the slices are further cut
into very narrow strips, no thicker
| than a fine knitting-needle, and these
have their ends prepared to enter suita
/ bic clamps for connection through the
| glass bulbs with the electric circuit.
/ About 500 of the bamboo fibers are bent
around a form in the shape of a slender
letter [, are enclosed in a practically air
tight mold and carboniZed in very hot
furnace. The factory at NIenlo Park has
now a capacity of 1 800 lamps per day !
Each lamp has resistance of 1875 ohms for
sixteen candle power, and is life" or du
ration is about 300 hours. ANY device |
that will Iengthen the life" of this carbon |
fiber Will Of course, make the system more
economical But that it is merely ques
ton of economy, affecting the practicable
ty of the lamp in no other way, is evident |
from the fact that a used-up lamp can
be replaced much more quickly and
safely than a broken lamp chimney |
Three or four turns of the glass bulb |
remove it, and as many more in the |
opposite direction, of course, replace it
again. This Edison demonstrated to
US by extinguishing a lamp and imme-
diately removing it. 1t was replaced in
from three to five seconds, and the turning
Of the key was alone necessary to relight it /
in as great perfection as before There was /
no hot glass to handle, no plumber was re-
quired, no connections were to be made |
gas-tight and no match dropped its charred |
end to soil the carpet. The plan is to have
a boy deliver daily these glass bulbs wher-
ever they are needed, small supply being
kept on hand at every house. Then when
ever a lamp fails it can be replaced at any
moment.
The tariff for each consumer will de
pend only on the electricity used, and not
upon the number of lamps that may be re-
quired Hence it will be an inducement
to the company to make the lamps as dur
able as possible. This removes the most
serious objection to Edison's system that
presents itself to an outsider. If, with
this commercial drawback, the system can
still be financially successful as compared
with illumination by gas, then the incan-
descent electric light is the light of the fu
ture, at least for domestic purposes.
Mr.. Edison explained the giving way of
the carbonized fiber in way that was en-
tirely new to me. Consumption by oxida-
tion has nothing to do with it, but the car
bon is volatilzed and and slowly trans
ported across from the negative. Every
lamp gives way at the negative pole; and
no fiber fails at any imperfect point, where
there is q nick made for instance unless
that point is near the negative pole. If it
is at the positive, the fiber is in no way
endangered by it.
The Edison lamp in its present form
represents the product of q vast outlay of
inventive energy as well as hard cash Diff
ficulty after difficulty has been met and
overcome Mr.. Edison has called to his
aid not only skillful mechanics, but expert
calculators and financiers. He
has now forty or fifty glass-blowers who
have been taught in his own shop, every
one of whom can make a lamp from be
ginning to end, so far as the work in glass
is concerned. Every point from the
dynamo machine up to the lamp,
has been experimentally tested with
the object of making com
merciaI success. The relation of parts,
that Is satisfactory with only Scientinc
experiment in view, is found not to hold
when machines and engines and condUc-
tors are increased in size up to the require
ments of vast commercial undertaking.
Hence the financial outlay and the months
Of delay before the present stage has been
reached. Now that the board of aldermen
have voted the privilege of laying conduc-
tors, Notwithstanding the mayors veto, the
work of establishing machines at central
stations and of laying conductors viii be
pushed forward with vigor. The con-
ductors, consisting of copper rods of
semi-circular section, with the fiat
sides turned toward each other, will 4
be placed in gas pipes. and the
whole intervening space between the con-
1uctors and the pipe will be filled with in
;ulating material. Each lamp viii be placed !
N an independent circuit running from one y
IF the main copper rods across to the other
The system may be likened to ladder, the
;ides of which correspond to the main con- 1
luctors, connected at the end with the
Iynamo machine, while the rounds answer r
o the cross circuits in which the lamps are |
,Iaced This is called connecting them in