DOC.
3
STATICS
OF
GRAVITATIONAL FIELD
145
[9]The term
on
the
righthand
side of the first
equation
should be
"X'2

ß'2."
The
"X" in
the third
equation
of the
first
line should have
a
prime.
[10]The
first
and last lines of
equations (4) as
well
as equation
(5) are
written
on
[p.
38]
of
Einstein's "Scratch Notebook"
(Vol.
3, Appendix A), together
with the remark "correct"
("richtig").
[11]See
Einstein
1907j
(Vol.
2,
Doc.
47), §20,
and Einstein 1911h
(Vol. 3,
Doc.
23),
p.
906.
[12]In
Einstein 1912d
(Doc.
4),
§4,
a
modified
field
equation
for
c
is
proposed
after Einstein
has shown that
a
contradiction follows from
equation
(5b)
in
connection with the relation
R
=
mgrad
c
derived
on
p.
364
below.
Presumably
because of
this
difficulty,
Einstein
con
sidered
withdrawing
his
paper
from
publication
(see
Einstein
to
Wilhelm
Wien,
11
March
1912
[Vol.
5,
Doc.
371]).
For further discussion of
this
problem,
see
the editorial
note,
"Einstein
on
Gravitation and
Relativity:
The Static
Field,"
p.
124.
[13]This
equation
(with
an
additional factor
4tt) is
written
on [p.
38]
of Einstein's "Scratch
Notebook"
(Vol. 3, Appendix A), together
with the remark "untenable"
("unhaltbar").
[14]The
term
on
the
righthand
side of the
equation
should
be
"a/c."
[15]This
equation
is
written
on [p.
38]
of Einstein's "Scratch Notebook"
(Vol. 3,
Appendix
A).
[16]The
denominator
of
"y"
should
be
"c2."
[17]This
equation
(without
the factor
m)
is
written
on [p.
38]
of Einstein's "Scratch
Notebook"
(Vol. 3,
Appendix
A).
[18]In
a
letter
to Besso,
Einstein
emphasized
the fact that the dimension of the
expression
for
the force differs from the usual
one (see
Einstein
to
Michele
Besso, 26
March
1912
[Vol. 5,
Doc.
377]).
[19]This
equation
is
written
on
[p.
38]
of Einstein's "Scratch Notebook"
(Vol. 3, Appendix
A).
[20]The first
factor "1/2"
in
this
equation
should be omitted.
[21]A
factor "1/2"
is
missing
in the
lefthand
side;
the factor
"E"
in
the
numerator
on
the
right
should
be
"E."
[22]See
Einstein 1911h
(Vol. 3,
Doc.
23), §3.
See also Einstein
1907j (Vol. 2,
Doc.
47),
§§18,
19.
[23]In
Einstein 1913c
(Doc.
16),
p.
1254,
such
a
clock
is
called
a
"light
clock"
("Licht
uhr")
as
opposed
to
a "gravitational
clock"
("Gravitationsuhr")
which
is
introduced below
on
p.
367. In
late June
1913
Einstein and Gunnar Nordström collaborated
on a
calculation related
to
a
comparison
between these
two clocks;
for
evidence,
see
the
entry
for
29
June
in
Ehrenfest's
Diary
"I,"
NeLR,
Ehrenfest
Archive, Notebooks,
ENB:415.
[24]See
Abraham
1912a,
p.
1.
[25]See
Einstein 1912d
(Doc.
4), §4.
[26]See
Abraham
1912f,
p.
1057,
for further elaboration of
this
point.
For
a
historical dis
cussion,
see
the editorial
note,
"Einstein
on
Gravitation and
Relativity:
The Static
Field,"
pp.
125126.