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281
Heroes of the Telegraph
·
John Munro
237
All
his
spare
time
was
thenceforth
devoted
to
the
development
of
his
design
and
the
construction
of
a
practical
type-printer.
As
the
work
grew
on
his
hands,
the
pale
young
student,
beardless
but
careworn,
became
more
and
more
engrossed
with
it,
until
his
nights
were
almost
entirely
given
to
experiment.
He
begrudged
the
time
which
had
to
be
spent
in
teaching
his
classes
and
the
fatigue
was
telling
upon
his
health,
so
in
1853
he
removed
to
Bowlingreen,
in
Warren
Co.,
Kentucky,
where
he
acquired
more
freedom
by
taking
pupils.
The
main
principle
of
his
type-printer
was
the
printing
of
each
letter
by
a
single
current;
the
Morse
instrument,
then
the
principal
receiver
in
America,
required,
on
the
other
hand,
an
average
of
three
currents
for
each
signal.
In
order
to
carry
out
this
principle
it
was
necessary
that
the
sending
and
receiving
apparatus
should
keep
in
strict
time
with
each
other,
or
be
synchronous
in
action;
and
to
effect
this
was
the
prime
difficulty
which
Professor
Hughes
had
to
overcome
in
his
work.
In
estimating
the
Hughes'
type-printer
as
an
invention
we
must
not
forget
the
state
of
science
at
that
early
period.
He
had
to
devise
his
own
governors
for
the
synchronous
mechanism,
and
here
his
knowledge
of
acoustics
helped
him.
Centrifugal
governors
and
pendulums
would
not
do,
and
he
tried
vibrators,
such
as
piano-strings
and
tuning-forks.
He
at
last
found
what
he
wanted
in
two
darning
needles,
borrowed
from
an
old
lady
in
the
house
where
he
lived.
These
steel
rods
fixed
at
one
end
vibrated
with
equal
periods,
and
could
be
utilised
in
such
a
way
that
the
printing
wheel
could
be
corrected
into
absolute
synchronism
by
each
signal
current.
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