, 1880-03-15
EdisOn's System Of Electric Lighting.

i Concerning the article on the Electric
Light in Scrs6ner, by Mr.. E Eiison's
mathematician, the editor received this
note:
EDITOR ScRIBNER's MONTHLY.
Dear Sir: 1 have read the paper by
Mr.. Francis Upton, and it is the first
correct and authoritative account of my
invention of the Electric Light.
Yours truly,
THOMAS A. EDISON.
| From the paper referred to we quote
the following:
Mr.. Edison's idea in regard to the
electric light was that, in all respects,
it should take the place of gas. Fol-
lowing the analogy OF water, the in
ventor conceived of system which
should resemble the Holly water works.
As the water is pumped directly into
pipes which convey it under pressure
to the point where it is to be used, SO
the electricity is to be forced into the
wires and delivered under pressure at
its destination. In the case of water,
after being used, it flows away by
means of q sewer-pipe, and ia lost. But
it is easy to imagine that the water used
in working machinery, for instance, in
stead of being lost, might be returned
to the pumps and used over and over
again. With such system as this, we
should have perfect analogy to the
Edison electric lighting system. The
electricity, after being distributed un
der pressure and used, is returned to
the central station. AS the light results
1 nf IoI m
is mere transmutation of the energy ex-
erted in the pumping process, 1t is
therefore seen that all which is essen
tial to an electric lighting system is the
generator (or pump, the two lines of
wire, one distributing the electricity,
the other bringing it back, and lamp
which transmutes into light the energy
carried by the electricity when it passes
from one wire to the other, and in
which the energy of the pressure ex
presses itself as the light. In Edison's
invention the amount of electricity de-
livered in the lamp is determined by
the size and resistance in the carbon,
Just as in water the amount of flow is
determined by the size of the openings.
AS a great many small jets of water can
5
many lamps or small escapes for cleo
tricity can be furnished from one wire.
AS in the case of water, the amount
of work done by electricity-either as
illuminant or motor - is dependent
quite as much upon the pressure from
which it escapes as upon the quantity
passing through the wires. We might
have system of lamps which would
give certain amount of light from
large quantities of electricity escaping
under low pressure, or another system
which could give an equal amount of
light from a small quantity of electrici
ty escaping under high pressure. As in
either case the amount of electricity
flowing through a wire is in proper
ton to the size of the wire, it will be
readily seen that the application of
pressure made by Mr.. Edison obviates
the main difficulty in the way of sub
division Il. e., in the way of the domes
tic use of the electric light, namely,
the enormous size and cost of conduc-
tors. The well-known principle of the
effect of pressure upon the dynamic
power of electricity had never been
utilized because the proper lamp was
still unknown. This lamp is MIR. Edi-
sons main discovery. In order to util
ize this, one of the plans devised by
him was to make the low of electricity
intermittent. Enough was allowed to
escape in short time, say one-third, to
keep the lamp all the time supplied. 1t
of course would require largo wire to
furnish the quantity of electricity
needed, yet two-thirds of the time the
wire would be inactive, during which
period it could be used to supply two
other lamps constructed on the same
principle. According to the doctrine
of probabilities, one-third of large
number of lamps would be in use all
the time. Such being the case, the
cost of conductor would be divided
among three lamps. The lamps were
so constructed as to burn steadily all
the while, although the electricity was
passing through them only one-third
of the time.
| Besides the enormous practical value
of the electric light, as domestic illu-
lninant and motor, it furnishes most
striking and beautiful illustration of
the convertibility of force. Mr.. Edi-
sons system of lighting gives a COM
pleted cycle of change. The sunlight
poured upon the rank vegetation of the
carboniferous forests, was gathered and
stored up, and has been waiting through
the ages to be converted again into
light. The latent force accumulated
during the primeval days, and garnered
up in the coal beds, is converted, after
passing in the steam engine through
the phases of chemical, molecular and
mechanical force, into electricity, which
only waits the touch of the inventors
genius to flash out into million do
nestle suns to illuminate myriad of
homes.