Lab
Library
Journal
Shop
Sign in
to keep
Share image
1
281
Heroes of the Telegraph
·
John Munro
172
All
these
apparatus
follow
in
the
track
of
Reis
and
Bourseul--that
is
to
say,
the
interruption
of
the
current
by
a
vibrating
contact.
It
was
fortunate
for
Bell
that
in
working
with
his
musical
telephone
an
accident
drove
him
into
a
new
path,
which
ultimately
brought
him
to
the
invention
of
a
speaking
telephone.
He
began
his
researches
in
1874
with
a
musical
telephone,
in
which
he
employed
the
interrupted
current
to
vibrate
the
receiver,
which
consisted
of
an
electro-magnet
causing
an
iron
reed
or
tongue
to
vibrate;
but,
while
trying
it
one
day
with
his
assistant,
Mr.
Thomas
A.
Watson,
it
was
found
that
a
reed
failed
to
respond
to
the
intermittent
current.
Mr.
Bell
desired
his
assistant,
who
was
at
the
other
end
of
the
line,
to
pluck
the
reed,
thinking
it
had
stuck
to
the
pole
of
the
magnet.
Mr.
Watson
complied,
and
to
his
astonishment
Bell
observed
that
the
corresponding
reed
at
his
end
of
the
line
thereupon
began
to
vibrate
and
emit
the
same
note,
although
there
was
no
interrupted
current
to
make
it.
A
few
experiments
soon
showed
that
his
reed
had
been
set
in
vibration
by
the
magneto-electric
currents
induced
in
the
line
by
the
mere
motion
of
the
distant
reed
in
the
neighbourhood
of
its
magnet.
This
discovery
led
him
to
discard
the
battery
current
altogether
and
rely
upon
the
magneto-induction
currents
of
the
reeds
themselves.
Moreover,
it
occurred
to
him
that,
since
the
circuit
was
never
broken,
all
the
complex
vibrations
of
speech
might
be
converted
into
sympathetic
currents,
which
in
turn
would
reproduce
the
speech
at
a
distance.
Marker
Marker
Fine marker
White-out
Fine white-out
Circle
Paint
Unmarker
Hand
Scalpel
Dice
Sieve
Purify
Undo
Redo
Start over
