DOCS.
225,
226
JUNE
1916 221
healthy.
De Haas
also,
likewise
his
wife
and children
(the
third
is
expected
next
month).[8]
He
has
now
been named Conservator at
the
local
Teyler Laboratory,
which makes
me
very happy
for him and for
myself.[9]
He will
now
be able
to
devote himself
exclusively
to scientific
work.
That
I,
that
is,
in
agreement
with
my colleagues,
could
suggest
that
he be
entrusted
with
the
position,
which
had
become available
is,
above
all,
thanks
to
the
research
you
conducted
with
him[10]
and thus
to
the interest
and kindness
you
have shown toward
him,
and for which
I
am
very
grateful to
you.
I
am
sending you
under
separate
cover
the
two
first
parts of
an
analysis
of
your
theory
of
gravitation.
Unfortunately
the translation
is not
ready
yet.[11]
I
made
an
effort to clothe
the
fundamentals
geometrically,
so
that the
use
of coordinates
is
avoided
as
far
as possible.[12]
With
warm regards, faithfully yours,
H. A.
Lorentz.
226. To
Hendrik
A.
Lorentz
Berlin,
17
June
1916
Dear
and
highly
esteemed
Colleague,
Your
lengthy
letter[1]
pleased
me
very much, mostly
because
of
the
extremely
welcome
news
that
de Haas has become Conservator
of
the
Teyler Laboratory.[2]
You
should not
thank
me
repeatedly
for
doing
the
Ampere investigation
with
him.[3]
For I chose him out of
egotism,
because I
happened
to
like
him
best,
and
my impression proved
to
be
right.
Our
colleagues
here have
preserved
a
lukewarm
memory
of
him
because of his
attitudes
about
impersonal
matters.
But
it
is
notable that
two
people
were
enchanted
by
the
de Haases:
the institute
mechanic[4]
and the
landlady
of
their
private
apartment.
Relay my
warm
greetings
to
both
from
me.[5]
I
hope
the
new
little
grandchild
turns
out
very
well.
In
the
summer
I want to
make
an
attempt
at
coming
to
Holland;
but it
is
difficult
to
obtain the
permit.
I
am
very pleased
that
you
are
engaging yourself
so
productively
with the
theory
of
gravitation.
I
liked
particularly well
the
direct
interpretation of
tensor
Kab,
which
was new
to
me.[6]
I
myself
worked
on
the
integration
of
the
field
equations
in first-order
approximation
and examined
gravitational
waves.[7]
The
results
are
in
part
astonishing.
There
are
three
kinds of
waves,
though
only
one
type transports
energy.
I
am
not
quite
finished
yet
with
the
theory
of emission in
material
systems.
But this
much
is
clear to
me:
that
the
quanta
difficulties affect
the
new
theory
of
gravitation just
as
much
as
Maxwell’s
theory.[8]
I
was delighted