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281
Heroes of the Telegraph
·
John Munro
232
In
1878
the
boulevards
of
Paris
were
lit
by
the
arc
lamps
of
Jablochkoff
during
the
season
of
the
Exhibition,
and
the
display
excited
a
widespread
interest
in
the
new
mode
of
illumination.
It
was
too
brilliant
for
domestic
use,
however,
and,
as
the
lamps
were
connected
one
after
another
in
the
same
circuit
like
pearls
upon
a
string,
the
breakage
of
one
would
interrupt
the
current
and
extinguish
them
all
but
for
special
precautions.
In
short,
the
electric
light
was
not
yet
'subdivided.'
Edison,
in
common
with
others,
turned
his
attention
to
the
subject,
and
took
up
the
neglected
incandescent
lamp.
He
improved
it
by
reducing
the
rod
of
carbon
to
a
mere
filament
of
charcoal,
having
a
comparatively
high
resistance
and
resembling
a
wire
in
its
elasticity,
without
being
so
liable
to
fuse
under
the
intense
heat
of
the
current.
This
he
moulded
into
a
loop,
and
mounted
inside
a
pear-shaped
bulb
of
glass.
The
bulb
was
then
exhausted
of
its
air
to
prevent
the
oxidation
of
the
carbon,
and
the
whole
hermetically
sealed.
When
a
sufficient
current
was
passed
through
the
filament,
it
glowed
with
a
dazzling
lustre.
It
was
not
too
bright
or
powerful
for
a
room;
it
produced
little
heat,
and
absolutely
no
fumes.
Moreover,
it
could
be
connected
not
in
but
across
the
main
circuit
of
the
current,
and
hence,
if
one
should
break,
the
others
would
continue
glowing.
Edison,
in
short,
had
'subdivided'
the
electric
light.
In
October,
1878,
he
telegraphed
the
news
to
London
and
Paris,
where,
owing
to
his
great
reputation,
it
caused
an
immediate
panic
in
the
gas
market.
As
time
passed,
and
the
new
illuminant
was
backward
in
appearing,
the
shares
recovered
their
old
value.
Edison
was
severely
blamed
for
causing
the
disturbance;
but,
nevertheless,
his
announcement
had
been
verified
in
all
but
the
question
of
cost.
The
introduction
of
a
practical
system
of
electric
lighting
employed
his
resources
for
several
years.
Dynamos,
types
of
lamps
and
conductors,
electric
meters,
safety
fuses,
and
other
appliances
had
to
be
invented.
In
1882
he
returned
to
New
York,
to
superintend
the
installation
of
his
system
in
that
city.
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