The Sleepwalkers (286 page)

16

Dedication
of
the
Ephemerides
for
1620
to
Lord
Napier.

17

Ibid
.

18

Harmonice
Mundi, Introduction to Book V.

19

"
Sed
res
est
certissima
exactissimaque,
quod
proportio,
quae
est
inter
binorum
quorumconque
planetarum
tempora
periodica,
sit
praecise
sesquialtera
proportionis
mediarum
distantiarum,
id
est
orbium
ipsorum
."
(
Ibid,
V, Cap. 3, Proposition No. 8.
)

20

Loc.
cit.

21

Loc.
cit.

22

Ibid.,
appendix to Book V
.

Part
IV Chapter X. COMPUTING A BRIDE

1

G.W.,
Vol. XVII, p. 79 seq. The following is a compressed version.

Part
IV Chapter XI. THE LAST YEARS

1

"To
Bianchi, 17.2.1619", G.W., Vol. XVII p. 321 seq.

2

"To
Bernegger,
20.5.1624",
Johannes
Kepler
in
seinen
Briefen,
II
,
p.
205
f.

3

1.10.1626.
Ibid.,
II,
p.
222
.
ff.

4

Loc.
cit.

5

Kepler
became
acquainted
with
Napier's
logarithms
in
1617:
"A
Scottish
baron
has
appeared
on
the
scene
(his
name
I
have
forgotten)
who
has
done
an
excellent
thing
by
transforming
all
multiplication
and
division
into
addition
and
subtraction..."
(
Ibid.,
II,
p.
101
.)
Since
Napier
did
not
at
first
explain
the
principle
behind
it,
the
thing
looked
like
black
magic
and
was
received
with
scepticism.
Old
Maestlin
remarked:
"It
is
not
fitting
for
a
professor
of
mathematics
to
manifest
childish
joy
just
because
reckoning
is
made
easier."
(Ca.,
p.
368.)

6

To
Bernegger,
20.5.1624
,
see
note
2.

7

Ca.,
p. 302.

8

"To
Bernegger,
6.4.1627",
Johannes
Kepler
in
seinen
Briefen,
11
,
p.
236
seq.

9

"To
Bernegger,
22.7.1629",
ibid.,
p. 292
.

10

"To
Bernegger,
2.3.1629",
ibid.,
p. 284 f
.

11

"To
Bernegger,
29.4.1629",
ibid.,
p. 286 f
.

12

"To
Ph.
Mueller,
27.10.1629",
ibid.,
p. 297
.

13

Cf.
Marjorie
Nicolson
essay,
Kepler,
the
Somnium,
and
John
Donne,
in
her
Science
and
Imagination
,
Oxford,
1956.

14

Kepler
added the following note to this passage:

"We
can
feel
the
warmth
of
the
moonlight
with
the
help
of
an
apparatus.
For
if
one
gathers
the
rays
of
the
full
moon
in
a
concave
parabolical
or
spherical
mirror,
then
one
feels
in
its
focus,
where
the
rays
meet,
a
warm
breath,
as
it
were.
I
noticed
that
in
Linz
when
I
was
engaged
in
other
experiments
with
mirrors,
without
thinking
of
the
warmth;
I
involuntarily
turned
around
to
see
whether
somebody
was
breathing
on
my
hand."

As
Ludwig
Gunther,
who
edited
and
translated
the
Somnium
(
Kepler
Traum
vom
Mond
,
Leipzig,
1898),
pointed
out,
this
passage
establishes
Kepler's
priority
in
discovering
that
the
moon
reflects
not
only
the
light,
but
also
some
of
the
heat
of
the
sun
–
a
fact
which
was
by
no
means
obvious
and
which
(according
to
Gunther,
p.
131)
was
only
established
by
C.
V.
Boyse
in
the
1890s.
The
ancients
believed
that
the
sunlight
lost
all
its
warmth
when
reflected
by
the
moon
(cf.
Plutarch
On
the
Face
in
the
Moon
Disc
).

15

Letter
to
Bartsch,
6.11.1629
,
Johannes
Kepler
in
seinen
Briefen,
II,
p.
303.

16

"To
Ph.
Mueller,
22.4.1630",
ibid,
p.
316
.

17

"Bartsch
to Ph. Mueller, 3.1.1631", ibid. II, p. 329.

18

Ibid.
II, p. 325
.

19

Ca.,
p. 431.

20

Quoted
by
"S.
Lansius
to
anon.,
24.1.1631",
Johannes
Kepler
in
seinen
Briefen,
II
,
p.
333.

21

From
which expression one might infer that they refused him the last
sacraments.

22

To
Bartsch,
Johannes
Kepler
in
seinen
Briefen,
II
,
p.
308.

PART
FIVE
THE
PARTING
OF
THE
WAYS

Part
V Chapter I. THE BURDEN OF PROOF

1

"To
Cosmo II, 31.5.1611", quoted by Gebler, op. cit., p. 36.

2

The
term
was
devised
by
a
member
of
the
Lynxes,
Demisiani,
and
announced
at
the
banquet
on
14
April,
1611.
See
E.
Rosen,
The
Naming
of
the
Telescope
,
New
York,
1947.