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281
Heroes of the Telegraph
·
John Munro
252
Science
appears
to
show
that
every
physical
process
is
reciprocal,
and
may
be
reversed.
With
this
principle
in
our
minds,
we
need
not
be
surprised
that
the
microphone
should
not
only
act
as
a
TRANSMITTER
of
sounds,
but
that
it
should
also
act
as
a
RECEIVER.
Mr.
James
Blyth,
of
Edinburgh,
was
the
first
to
announce
that
he
had
heard
sounds
and
even
speech
given
out
by
a
microphone
itself
when
substituted
for
the
telephone.
His
transmitting
microphone
and
his
receiving
one
were
simply
jelly-cans
filled
with
cinders
from
the
grate.
It
then
transpired
that
Professor
Hughes
had
previously
obtained
the
same
remarkable
effects
from
his
ordinary
'pencil'
microphones.
The
sounds
were
extremely
feeble,
however,
but
the
transmitting
microphones
proved
the
best
articulating
ones.
Professor
Hughes
at
length
constructed
an
adjustable
hammer-and-anvil
microphone
of
gas-carbon,
fixed
to
the
top
of
a
resonating
drum,
which
articulated
fairly
well,
although
not
so
perfectly
as
a
Bell
telephone.
Perhaps
a
means
of
improving
both
the
volume
and
distinctness
of
the
articulation
will
yet
be
forthcoming
and
we
may
be
able
to
speak
solely
by
the
microphone,
if
it
is
found
desirable.
The
marvellous
fact
that
a
little
piece
of
charcoal
can,
as
it
were,
both
listen
and
speak,
that
a
person
may
talk
to
it
so
that
his
friend
can
hear
him
at
a
similar
piece
a
hundred
miles
away,
is
a
miracle
of
nineteenth
century
science
which
far
transcends
the
oracles
of
antiquity.
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