DOCS. 513-514
MARCH 1914 381
is to
say
that
I
succeeded
in
proving
that the
gravit.
equations
hold for
arbitrarily
moving
reference
systems,[2]
and thus that the
hypothesis
of
the
equivalence
of acceleration and
the
gravitational
field
is
absolutely
correct,
in
the
widest
sense.
Now
the
harmony
of
the
mutual
relationships
in
the
theory is
such
that
I
no longer
have
the
slightest
doubt about
its correctness.
Nature
shows
us only
the
tail
of the
lion. But
there
is
no
doubt
in
my
mind
that the
lion
belongs
with it
even
if he cannot
reveal himself
to
the
eye
all at
once
because
of
his
huge
dimensions. We
see
him
only
the
way
a
louse
that
sits
upon
him
would do. I will
come
to
see
you
during summer
vacation
and will tell
you
about
everything.[3]
The
name
of that
capable young physicist-technician
is
Dellenbach,
and
he
is
a
third-
year student.[4]
One
day
he
will
probably
make
for
an
excellent
addition
to
the
Poly.
I
am
leaving
around the
21st,
first to
Holland
(to
Lorentz and
Ehrenfest),[5]
and then
toward
the
first of
April,
to
Berlin.
There
I will
probably
get my own
institute[6]
and
an
assistant.[7]
Because of
my
predilection
for
collaborative
work,
the latter
is
a special
blessing.
From
an
objective
point
of
view,
I
must
say
that
I
am
doing
the
right
thing by
going
there,
since I believe
that
my
personal relationships
to
many
of
my
colleagues
there
should
prove
fruitful.
Especially
the astronomers
are
important
to
me
(at
the
moment).
I
found
something
nice
regarding
the statistical evaluation of
long, seemingly
irregular
series
of observation
(e.g.,
solar
activity,
terrestrial
magnetism,
etc.).[8]
I must tell
you
about
this too
when
I
come.
Cordial
greetings
to
you
and
your
wife from
your
Einstein
My
compliments
to Prof.
Hugenin![9]
514.
To
Michele
Besso
[Zurich, ca.
10
March
1914][1]
Dear
Michele,
Please
don't
be too
angry
with
me
because of
my
inordinately
long
silence. I have
been
working
furiously
and,
what's
best,
with
great
success.
More about that later.
If
all
goes smoothly,
we
will be
leaving
Zurich
(plagued
by
a
bunch of
legal
difficulties)[2] on
the
20th
of
this
month.
My
wife
is
going
with
the children
to
Locarno
for
3 weeks,
because
our
little
boy was
quite ill
and needs
to
convalesce.[3]
I will
go
to
visit
Ehrenfest and
Lorentz,[4]
and
then
to Berlin.
The
boy
suffered
from
whooping
cough,
influenza,
and
an
inflammation of the
middle
ear,
all
at
the
same
time.
The
whooping cough
is
not
yet
quite
gone.