The Sleepwalkers (125 page)

By
February
1596,
the
rough
draft
of
the
book
was
completed
and
Kepler
asked
his
superiors
in
Gratz
for
leave
of
absence
to
visit
his
native
Wuerttemberg
and
make
arrangements
for
its
publication.
He
asked
for
two
months,
but
stayed
away
for
seven,
as
he
had
become
involved
in
a
typically
Keplerian
chimera.
He
had
persuaded
Frederick,
Duke
of
Wuerttemberg,
to
have
a
model
of
the
universe,
incorporating
the
five
perfect
solids,
made
in
the
shape
of
a
drinking
cup.
"A
childish
or
fatal
craving
for
the
favour
of
princes,"
as
he
later
confessed,
had
driven
him
to
Stuttgart,
to
Frederick's
court,
to
whom
he
explained
his
idea
in
a
letter:

"Since
the
Almighty
granted
me
last
summer
a
major
inventum
in
astronomy,
after
lengthy,
unsparing
toil
and
diligence;
which
same
inventum
I
have
explained
in
a
special
booklet
which
I
am
willing
to
publish
any
time;
which
whole
work
and
demonstration
thereof
can
be
fittingly
and
gracefully
represented
by
a
drinking
cup
of
an
ell
in
diameter
which
then
would
be
a
true
and
genuine
likeness
of
the
world
and
model
of
the
creation
insofar
as
human
reason
may
fathom,
and
the
like
of
which
has
never
before
been
seen
or
heard
of
by
any
man;
therefore
I
have
postponed
the
preparation
of
such
a
model
or
its
showing
to
any
man
to
the
present
time
of
my
arrival
from
Styria,
intending
to
put
this
true
and
correct
model
of
the
world
before
the
eyes
of
your
Grace,
as
my
natural
sovereign,
for
him
to
see
it
as
the
first
man
on
earth."
¹

Kepler
went
on
to
suggest
that
the
various
parts
of
the
cup
should
be
made
by
different
silversmiths,
and
then
fitted
together,
to
make
sure
that
the
cosmic
secret
would
not
leak
out.
The
signs
of
the
planets
could
be
cut
in
precious
stones
–
Saturn
in
diamond,
Jupiter
in
jacinth,
the
moon
a
pearl,
and
so
on.
The
cup
would
serve
seven
different
kinds
of
beverage,
conducted
by
concealed
pipes
from
each
planetary
sphere
to
seven
taps
on
its
rim.
The
sun
will
provide
a
delicious
aqua
vita
,
Mercury
brandy,
Venus
mead,
the
moon
water,
Mars
a
strong
Vermouth,
Jupiter
"a
delicious
new
white
wine",
and
Saturn
"a
bad
old
wine
or
beer",
"whereby
those
ignorant
in
astronomical
matters
could
be
exposed
to
shame
and
ridicule."
Assuring
Frederick
that
in
ordering
the
cup
he
would
do
a
favour
to
the
arts
and
a
service
to
God
Almighty,
Kepler
remained
Frederick's
obedient
servant,
hoping
for
the
best.

The
Duke
wrote
on
the
margin
of
Kepler's
letter:
"Let
him
first
make
a
model
of
copper
and
when
we
see
it
and
decide
that
it
is
worth
being
made
in
silver,
the
means
shall
not
want."
Kepler's
letter
was
dated
17
February
and
the
Duke's
answer
was
transmitted
to
him
on
the
next
day;
Frederick's
imagination
had
obviously
caught
on.
But
Kepler
had
no
money
to
make
a
copper
model,
as
he
resentfully
conveyed
to
the
Duke
in
his
next
letter;
instead,
he
settled
down
to
the
Herculean
task
of
making
a
paper
model
of
all
the
planetary
orbits
and
the
five
perfect
solids
in
between.
He
laboured
day
and
night
for
a
week;
years
later
he
nostalgically
remarked
that
it
had
been
quite
a
pretty
model,
made
out
in
paper
of
different
colours,
with
all
the
orbits
in
blue.

When
the
paper
monster
was
finished,
he
sent
it
to
the
Duke,
apologising
for
its
clumsiness
and
huge
dimensions.
Again
promptly
on
the
next
day,
the
Duke
ordered
his
chancellery
to
ask
for
the
expert
opinion
of
Professor
Maestlin.
The
good
Maestlin
wrote
to
Frederick
that
Kepler's
cup
would
represent
a
"glorious
work
of
erudition",
and
the
Duke
wrote
on
the
margin:
"Since
this
is
so,
we
are
content
that
the
work
should
be
executed."

But
apparently
it
had
been
easier
for
God
to
build
the
world
around
the
five
polyhedra
than
for
the
silversmiths
to
execute
a
copy
of
it.
Besides,
Frederick
did
not
want
the
cosmic
mystery
in
the
form
of
a
drinking
cup,
but
to
have
it
encased
in
a
celestial
globe.
Kepler
made
another
paper
model,
left
it
with
the
silversmith,
and
in
September
returned
to
Gratz,
having
wasted
nearly
six
months
at
Frederick's
court.
But
the
Duke
would
not
drop
the
project,
and
it
dragged
on
for
several
years.
In
January
'98,
Kepler
wrote
to
poor
Maestlin
(who
now
served
as
the
go-between):
"If
the
Duke
agrees,
it
would
be
best
to
break
up
the
whole
junk
and
refund
the
silver
to
him...
The
thing
is
hardly
worth
while...
I
started
it
too
ambitiously."
²
But
six
months
later,
he
submitted
via
Maestlin
a
new
project.
The
cup,
which
had
turned
into
a
globe,
was
now
to
turn
into
a
mobile
planetarium,
driven
by
a
clockwork.
The
description
of
it
occupied
ten
printed
pages
in
folio.
Kepler
informed
the
Duke
that
a
Frankfurt
mathematician,
Jacob
Cuno,
had
offered
to
construct
a
planetarium
which
would
reproduce
the
heavenly
motions
"within
an
error
of
one
degree
for
the
next
six
or
ten
thousand
years";
but,
Kepler
explained,
such
a
machine
would
be
too
large
and
costly,
and
proposed
a
more
modest
one,
guaranteed
for
a
century
only.
"For
it
is
not
to
be
hoped
(apart
from
the
Last
Judgement)
that
such
a
work
would
remain
undisturbed
in
one
place
over
a
hundred
years.
Too
many
wars,
fires
and
other
changes
are
wont
to
occur."
³