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281
Heroes of the Telegraph
·
John Munro
274
In
January
1850,
a
paper
on
telegraph
lines
and
apparatus,
in
which
the
theory
of
the
electro-static
charge
in
insulated
wires,
as
well
as
methods
and
formula:
for
the
localising
of
faults
in
underground
wires
were
first
established.
In
1851,
the
firm
erected
the
first
automatic
fire
telegraphs
in
Berlin,
and
in
the
same
year,
Werner
Siemens
wrote
a
treatise
on
the
experience
gained
with
the
underground
lines
of
the
Prussian
telegraph
system.
The
difficulty
of
communicating
through
long
underground
lines
led
him
to
the
invention
of
automatic
translation,
which
was
afterwards
improved
upon
by
Steinheil,
and,
in
1852,
he
furnished
the
Warsaw-Petersburg
line
with
automatic
fast-speed
writers.
The
messages
were
punched
in
a
paper
band
by
means
of
the
well-known
Siemens'
lever
punching
apparatus,
and
then
automatically
transmitted
in
a
clockwork
instrument.
In
1854
the
discovery
(contemporaneous
with
that
of
Frischen)
of
simultaneous
transmission
of
messages
in
opposite
directions,
and
multiplex
transmission
of
messages
by
means
of
electro-magnetic
apparatus.
The
'duplex'
system
which
is
now
employed
both
on
land
lines
and
submarine
cables
had
been
suggested
however,
before
this
by
Dr.
Zetsche,
Gintl,
and
others.
In
1856
he
invented
the
Siemens'
magneto-electric
dial
instrument
giving
alternate
currents.
From
this
apparatus
originated
the
well-known
Siemens'
armature,
and
from
the
receiver
was
developed
the
Siemens'
polarised
relay,
with
which
the
working
of
submarine
and
other
lines
could
be
effected
with
alternate
currents;
and
in
the
same
year,
during
the
laying
of
the
Cagliari
to
Bona
cable,
he
constructed
and
first
applied
the
dynamometer,
which
has
become
of
such
importance
in
the
operations
of
cable
laying.
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