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281
Heroes of the Telegraph
·
John Munro
7
In
the
latter
half
of
the
eighteenth
century,
many
other
suggestions
of
telegraphs
based
on
the
known
properties
of
the
electric
fire
were
published;
for
example,
by
Joseph
Bozolus,
a
Jesuit
lecturer
of
Rome,
in
1767;
by
Odier,
a
Geneva
physicist,
in
1773,
who
states
in
a
letter
to
a
lady,
that
he
conceived
the
idea
on
hearing
a
casual
remark,
while
dining
at
Sir
John
Pringle's,
with
Franklin,
Priestley,
and
other
great
geniuses.
'I
shall
amuse
you,
perhaps,
in
telling
you,'
he
says,'that
I
have
in
my
head
certain
experiments
by
which
to
enter
into
conversation
with
the
Emperor
of
Mogol
or
of
China,
the
English,
the
French,
or
any
other
people
of
Europe...
You
may
intercommunicate
all
that
you
wish
at
a
distance
of
four
or
five
thousands
leagues
in
less
than
half
an
hour.
Will
that
suffice
you
for
glory?'
George
Louis
Lesage,
in
1782,
proposed
a
plan
similar
to
'C.
M.'s,'
using
underground
wires.
An
anonymous
correspondent
of
the
JOURNAL
DE
PARIS
for
May
30,
1782,
suggested
an
alarm
bell
to
call
attention
to
the
message.
Lomond,
of
Paris,
devised
a
telegraph
with
only
one
wire;
the
signals
to
be
read
by
the
peculiar
movements
of
an
attracted
pith-ball,
and
Arthur
Young
witnessed
his
plan
in
action,
as
recorded
in
his
diary.
M.
Chappe,
the
inventor
of
the
semaphore,
tried
about
the
year
1790
to
introduce
a
synchronous
electric
telegraph,
and
failed.
Don
Francisco
Salva
y
Campillo,
of
Barcelona,
in
1795,
proposed
to
make
a
telegraph
between
Barcelona
and
Mataro,
either
overhead
or
underground,
and
he
remarks
of
the
wires,
'at
the
bottom
of
the
sea
their
bed
would
be
ready
made,
and
it
would
be
an
extraordinary
casualty
that
should
disturb
them.'
In
Salva's
telegraph,
the
signals
were
to
be
made
by
illuminating
letters
of
tinfoil
with
the
spark.
Volta's
great
invention
of
the
pile
in
1800
furnished
a
new
source
of
electricity,
better
adapted
for
the
telegraph,
and
Salva
was
apparently
the
first
to
recognise
this,
for,
in
the
same
year,
he
proposed
to
use
it
and
interpret
the
signals
by
the
twitching
of
a
frog's
limb,
or
the
decomposition
of
water.
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