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1
281
Heroes of the Telegraph
·
John Munro
114
The
bathometer,
or
attraction-meter,
was
brought
out
in
1876,
and
exhibited
at
the
Loan
Exhibition
in
South
Kensington.
The
elastic
bottom
of
the
mercury
chamber
was
supported
by
volute
springs
which,
always
having
the
same
tension,
caused
a
portion
of
the
mercury
to
rise
or
fall
in
a
spiral
tube
of
glass,
according
to
the
variations
of
the
earth's
attraction.
The
whole
was
kept
at
an
even
temperature,
and
correction
was
made
for
barometric
influence.
Though
of
high
scientific
interest,
the
apparatus
appears
to
have
failed
at
the
time
from
its
very
sensitiveness;
the
waves
on
the
surface
of
the
sea
having
a
greater
disturbing
action
on
its
readings
than
the
change
of
depth.
Siemens
took
a
great
interest
in
this
very
original
machine,
and
also
devised
a
form
applicable
to
the
measurement
of
heights.
Although
he
laid
the
subject
aside
for
some
years,
he
ultimately
took
it
up
again,
in
hopes
of
producing
a
practical
apparatus
which
would
be
of
immediate
service
in
the
cable
expeditions
of
the
s.s.
Faraday.
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