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Heroes of the Telegraph
·
John Munro
250
Professor
Hughes
communicated
his
results
to
the
Royal
Society
in
the
early
part
of
1878,
and
generously
gave
the
microphone
to
the
world.
For
his
own
sake
it
would
perhaps
have
been
better
had
he
patented
and
thus
protected
it,
for
Mr.
Edison,
recognising
it
as
a
rival
to
his
carbon-transmitter,
then
a
valuable
property,
claimed
it
as
an
infringement
of
his
patents
and
charged
him
with
plagiarism.
A
spirited
controversy
arose,
and
several
bitter
lawsuits
were
the
consequence,
in
none
of
which,
however,
Professor
Hughes
took
part,
as
they
were
only
commercial
trials.
It
was
clearly
shown
that
Clerac,
and
not
Edison,
had
been
the
first
to
utilise
the
variable
resistance
of
powdered
carbon
or
plumbage
under
pressure,
a
property
on
which
the
Edison
transmitter
was
founded,
and
that
Hughes
had
discovered
a
much
wider
principle,
which
embraced
not
only
the
so-called
'semi-conducting'
bodies,
such
as
carbon;
but
even
the
best
conductors,
such
as
gold,
silver,
and
other
metals.
This
principle
was
not
a
mere
variation
of
electrical
conductivity
in
a
mass
of
material
brought
about
by
compression,
but
a
mysterious
variation
in
some
unknown
way
of
the
strength
of
an
electric
current
in
traversing
a
loose
joint
or
contact
between
two
conductors.
This
discovery
of
Hughes
really
shed
a
light
on
the
behaviour
of
Edison's
own
transmitter,
whose
action
he
had
until
then
misunderstood.
It
was
now
seen
that
the
particles
of
carbon
dust
in
contact
which
formed
the
button
were
a
congeries
of
minute
micro-phones.
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