46 DOCS.
38,
39
OCTOBER-DECEMBER
1914
second device in which
the
friction
wave
is
the
driving
element
(thus
correspond-
ing
to
y2)
and
which has been constructed
similarly
to
that
first
one.
What
I have been
only planning up
to
now
but
for lack of
means
have not
yet
carried out
is
the
combination
corresponding
to
your problem.
I have
also
considered
arrangements
for
the
evaluation of
ƒy2dx,
but unfortu-
nately
have likewise
not
yet
been able to have them
carried
out.
The
examination
of
this
value
frequently plays
a
role in
the statistical
analyses
on magnetic
inter-
ference.
(Right
now
I
am
having
the
mean
values for
y2
determined
as a
tentative
test
using a
calculational
procedure suggested by
Prof.
Bidlingmaier
in
Munich[9]
in order
to
see
if
this
procedure
is
suited for routine
use.)
I
would
very
much
like
to take
up your proposition
sometime and discuss
with
you
the construction
principles
of devices for such
types
of
integrations.
You
might
come
here
once
and examine
the
two
mentioned
instruments
along
with their
operation? We
could
then
proceed
from there.
I
am
almost
always
here at
your disposal (aside
from
Monday
and
Thursday afternoons) upon prear-
rangement (poss. by telephone during
the
morning
hours
Potsdam
287).
Then
I
could also show
you
some
calculations in which
I
determined
for
a
particular
purpose
the characteristic ƒF(t)$(t
+
A)dt.
With
amicable
greetings, yours very truly,
Ad. Schmidt.
Note at
head
of
fourth
page:
“Namur
Military
Weather
Station, to Officers Principal
Schwarzschild.”
39.
To Paul
Ehrenfest
[Berlin, beginning
December
1914][1]
Dear
Ehrenfest,
You
are
just
as
kind
a
person as
I
am a
vile
beast.
It
cut
me
to
the
quick
that
you
didn’t
reproach
me
for
my
dreadful sloth in
writing,
and
even
invite
me so
cordially
as
well.
Presently,
I cannot
leave here
easily,
especially
since
I
am
just
in
the
process
of
starting
an
interesting experimental investigation
with
de
Haas.[2]
Therefore, right
at the moment
I
would
prefer
not to
take
a
trip
but
would
prefer
to
delay my
visit
to
a
time when
we are
both
on
vacation.
It
would
also be awkward for
me
to cancel
a
few
course
lectures
just
on a
whim
(I
am
lecturing
on
relativity).[3]
But
I
would
come
immediately anytime
if in
that
way
I
could be
of service to
a
person
or a cause.
The international
catastrophe
weighs
heavily
on me an
international
person.
Living
in
this
“great
age”
it
is
hard
to
understand that
we
belong
to
this
mad,