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281
Heroes of the Telegraph
·
John Munro
246
Because
of
its
cheapness,
its
conducting
power,
and
its
non-oxidisability,
carbon
is
the
most
select
material.
A
piece
of
charcoal
no
bigger
than
a
pin's
head
is
quite
sufficient
to
produce
articulate
speech.
Gas-carbon
operates
admirably,
but
the
best
carbon
is
that
known
as
willow-charcoal,
used
by
artists
in
sketching,
and
when
this
is
impregnated
with
minute
globules
of
mercury
by
heating
it
white-hot
and
quenching
it
in
liquid
mercury,
it
is
in
a
highly
sensitive
microphonic
condition.
The
same
kind
of
charcoal
permeated
by
platinum,
tin,
zinc,
or
other
unoxidisable
metal
is
also
very
suitable;
and
it
is
a
significant
fact
that
the
most
resonant
woods,
such
as
pine,
poplar,
and
willow,
yield
the
charcoals
best
adapted
for
the
microphone.
Professor
Hughes'
experimental
apparatus
is
of
an
amusingly
simple
description.
He
has
no
laboratory
at
home,
and
all
his
experiments
were
made
in
the
drawing-room.
His
first
microphones
were
formed
of
bits
of
carbon
and
scraps
of
metal,
mounted
on
slips
of
match-boxes
by
means
of
sealing-wax;
and
the
resonance
pipes
on
which
they
were
placed
to
reinforce
the
effect
of
minute
sounds,
were
nothing
more
than
children's
toy
money
boxes,
price
one
halfpenny,
having
one
of
the
ends
knocked
out.
With
such
childish
and
worthless
materials
he
has
conquered
Nature
in
her
strongholds,
and
shown
how
great
discoveries
can
be
made.
The
microphone
is
a
striking
illustration
of
the
truth
that
in
science
any
phenomenon
whatever
may
be
rendered
useful.
The
trouble
of
one
generation
of
scientists
may
be
turned
to
the
honour
and
service
of
the
next.
Electricians
have
long
had
sore
reasons
for
regarding
a
'bad
contact'
as
an
unmitigated
nuisance,
the
instrument
of
the
evil
one,
with
no
conceivable
good
in
it,
and
no
conceivable
purpose
except
to
annoy
and
tempt
them
into
wickedness
and
an
expression
of
hearty
but
ignominious
emotion.
Professor
Hughes,
however,
has
with
a
wizard's
power
transformed
this
electrician's
bane
into
a
professional
glory
and
a
public
boon.
Verily
there
is
a
soul
of
virtue
in
things
evil.
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