158
DOCS. 211-213
JULY 1910
relations
in
four dimensions
seems
to
me
to
be
an
advance
comparable,
for
example,
to
the
introduction of
complex
functions in
the
hydrodynamics
&
electrostatics of
two
dimensions.[10] I
have
probably
expressed myself wrongly
in this
respect
when
I
talked
with
you
in
Salzburg.[11]
The conditions
for the events
(differential equations)
are
symmetrical
in
four
dimensions;
this
realization
makes
finding
those conditions easier.
The
limit
of the
significance
of
the
four-dimensional
approach
seems
to
me
to consist in
the
fact
that
in
the
solutions of those
equations
that
are
of interest
to
us
the
four
dimensions do not
appear
in
the
same
manner.
P.S. I
am
not
going
to
Prague.
The
Ministry-as I
hear
from Prague-has
raised
objections.[12]
212. From
Geza
Müller[1]
[Schaffhausen]
Feldstr.
17
Emmersberg
[1
July 1910]
I
am
sending
you
here
a
likeness
of
my
glider,[2]
along
with
my
best
regards,
G.
Müller
213. To
Lucien Chavan
[Zurich,
2
July
1910]
Dear
Mr. Chavan:
Thank
you very
much for
what
you
sent
me,
especially
for
the
splendid graphite
resistor.[1]
At the
same
time
I
am
sending
you-finally-the
small
sum.
We
are
fine. I
hope
that
the
same
applies
to
you.
Greetings to
you
and Mrs.
Chavan,
your
Einstein
My
wife
and the
kid also send
their
greetings.