The Sleepwalkers (174 page)

5.
The Impact of the Telescope

It
was
the
invention
of
the
telescope
which
brought
Kepler
and
Galileo,
each
travelling
along
his
own
orbit,
to
their
closest
conjunction.
To
pursue
the
metaphor,
Kepler's
orbit
reminds
one
of
the
parabola
of
comets
which
appear
from
infinity
and
recede
into
it;
Galileo's
as
an
eccentric
ellipse,
closed
upon
itself.

The
telescope
was,
as
already
mentioned,
not
invented
by
Galileo.
In
September
1608,
a
man
at
the
annual
Frankfurt
fair
offered
a
telescope
for
sale
which
had
a
convex
and
a
concave
lens,
and
magnified
seven
times.
On
2
October,
1608,
the
spectacle-maker
Johann
Lippershey
of
Middleburg
claimed
a
licence
for
thirty
years
from
the
Estates
General
of
the
Netherlands
for
manufacturing
telescopes
with
single
and
double
lenses.
In
the
following
month,
he
sold
several
of
these,
for
three
hundred
and
six
hundred
gilders
respectively,
but
was
not
granted
an
exclusive
licence
because
in
the
meantime
two
other
men
had
claimed
the
same
invention.
Two
of
Lippershey's
instruments
were
sent
as
a
gift
by
the
Dutch
Government
to
the
King
of
France;
and
in
April
1609,
telescopes
could
be
bought
in
spectacle-makers'
shops
in
Paris.
In
the
summer
of
1609,
Thomas
Harriot
in
England
made
telescopic
observations
of
the
moon,
and
drew
maps
of
the
lunar
surface.
In
the
same
year,
several
of
the
Dutch
telescopes
found
their
way
to
Italy
and
were
copied
there.

Galileo
himself
claimed
in
the
Messenger
from
the
Stars
that
he
had
merely
read
reports
of
the
Dutch
invention,
and
that
these
had
stimulated
him
to
construct
an
instrument
on
the
same
principle,
which
he
succeeded
in
doing
"through
deep
study
of
the
theory
of
refraction".
Whether
he
actually
saw
and
handled
one
of
the
Dutch
instruments
brought
to
Italy
is
a
question
without
importance,
for
once
the
principle
was
known,
lesser
minds
than
Galileo's
could
and
did
construct
similar
gadgets.
On
8
August,
1609,
he
invited
the
Venetian
Senate
to
examine
his
spy-glass
from
the
tower
of
St.
Marco,
with
spectacular
success;
three
days
later,
he
made
a
present
of
it
to
the
Senate,
accompanied
by
a
letter
in
which
he
explained
that
the
instrument,
which
magnified
objects
nine
times,
would
prove
of
utmost
importance
in
war.
It
made
it
possible
to
see
"sails
and
shipping
that
were
so
far
off
that
it
was
two
hours
before
they
were
seen
with
the
naked
eye,
steering
full-sail
into
the
harbour",
¹⁷
thus
being
invaluable
against
invasion
by
sea.
It
was
not
the
first
and
not
the
last
time
that
pure
research,
that
starved
cur,
snapped
up
a
bone
from
the
warlords'
banquet.

The
grateful
Senate
of
Venice
promptly
doubled
Galileo's
salary
to
a
thousand
scudi
per
year,
and
made
his
professorship
at
Padua
(which
belonged
to
the
Republic
of
Venice)
a
lifelong
one.
It
did
not
take
the
local
spectacle-makers
long
to
produce
telescopes
of
the
same
magnifying
power,
and
to
sell
in
the
streets
for
a
few
scudi
an
article
which
Galileo
had
sold
the
Senate
for
a
thousand
a
year
–
to
the
great
amusement
of
all
good
Venetians.
Galileo
must
have
felt
his
reputation
threatened,
as
in
the
affair
of
the
military
compass;
but,
fortunately,
this
time
his
passion
was
diverted
into
more
creative
channels.
He
began
feverishly
to
improve
his
telescope,
and
to
aim
it
at
the
moon
and
stars,
which
previously
had
attracted
him
but
little.
Within
the
next
eight
months
he
succeeded,
in
his
own
words:

"
…
by
sparing
neither
labour
nor
expense,
in
constructing
for
myself
an
instrument
so
superior
that
objects
seen
through
it
appear
magnified
nearly
a
thousand
times,
and
more
than
thirty
times
nearer
than
if
viewed
by
the
natural
powers
of
sight
alone."

The
quotation
is
from
Sidereus
Nuncius
,
the
Messenger
from
the
Stars
,
published
in
Venice
in
March
1610.
It
was
Galileo's
first
scientific
publication,
and
it
threw
his
telescopic
discoveries
like
a
bomb
into
the
arena
of
the
learned
world.
It
not
only
contained
news
of
heavenly
bodies
"which
no
mortal
had
seen
before";
it
was
also
written
in
a
new,
tersely
factual
style
which
no
scholar
had
employed
before.
So
new
was
this
language
that
the
sophisticated
Imperial
Ambassador
in
Venice
described
the
Star
Messenger
as
"a
dry
discourse
or
an
inflated
boast,
devoid
of
all
philosophy".
¹⁸
In
contrast
to
Kepler's
exuberant
baroque
style,
some
passages
of
the
Sidereus
Nuncius
would
almost
qualify
for
the
austere
pages
of
a
contemporary
"Journal
of
Physics".