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281
Heroes of the Telegraph
·
John Munro
276
The
reversibility
of
the
dynamo
was
enunciated
by
Werner
Siemens
in
1867;
but
it
was
not
experimentally
demonstrated
on
any
practical
scale
until
1870,
when
M.
Hippolite
Fontaine
succeeded
in
pumping
water
at
the
Vienna
international
exhibition
by
the
aid
of
two
dynamos
connected
in
circuit;
one,
the
generator,
deriving
motion
from
a
hydraulic
engine,
and
in
turn
setting
in
motion
the
receiving
dynamo
which
worked
the
pump.
Professor
Clerk
Maxwell
thought
this
discovery
the
greatest
of
the
century;
and
the
remark
has
been
repeated
more
than
once.
But
it
is
a
remark
which
derives
its
chief
importance
from
the
man
who
made
it,
and
its
credentials
from
the
paradoxical
surprise
it
causes.
The
discovery
in
question
is
certainly
fraught
with
very
great
consequences
to
the
mechanical
world;
but
in
itself
it
is
no
discovery
of
importance,
and
naturally
follows
from
Faraday's
far
greater
and
more
original
discovery
of
magneto-electric
generation.
In
1874,
Dr.
Siemens
published
a
treatise
on
the
laying
and
testing
of
submarine
cables.
In
1875,
1876
and
1877,
he
investigated
the
action
of
light
on
crystalline
selenium,
and
in
1878
he
studied
the
action
of
the
telephone.
The
recent
work
of
Dr.
Siemens
has
been
to
improve
the
pneumatic
railway,
railway
signalling,
electric
lamps,
dynamos,
electro-plating
and
electric
railways.
The
electric
railway
at
Berlin
in
1880,
and
Paris
in
1881,
was
the
beginning
of
electric
locomotion,
a
subject
of
great
importance
and
destined
in
all
probability,
to
very
wide
extension
in
the
immediate
future.
Dr.
Siemens
has
received
many
honours
from
learned
societies
at
home
and
abroad;
and
a
title
equivalent
to
knighthood
from
the
German
Government.
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