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281
Heroes of the Telegraph
·
John Munro
207
The
property
on
which
the
receiver
was
based
had
been
observed
and
applied
by
him
some
time
before.
When
a
current
is
passed
from
a
metal
contact
through
certain
chemical
salts,
a
lubricating
effect
was
noticeable.
Thus
if
a
metal
stylus
were
rubbed
or
drawn
over
a
prepared
surface,
the
point
of
the
stylus
was
found
to
slip
or
'skid'
every
time
a
current
passed
between
them,
as
though
it
had
been
oiled.
If
your
pen
were
the
stylus,
and
the
paper
on
which
you
write
the
surface,
each
wave
of
electricity
passing
from
the
nib
to
the
paper
would
make
the
pen
start,
and
jerk
your
fingers
with
it.
He
applied
the
property
to
the
recording
of
telegraph
signals
without
the
help
of
an
electro-magnet,
by
causing
the
currents
to
alter
the
friction
between
the
two
rubbing
surfaces,
and
so
actuate
a
marker,
which
registered
the
message
as
in
the
Morse
system.
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