996 CALENDAR 1915
Valkyrie. Later,
with Elsa and
Ilse,
signs
another
postcard
with
cameo portraits
of
the leaders
of
the Central
powers,
entitled "In Battle United." Above the
picture,
Einstein has
written
"Einigkeit
macht stark!" Provenance: Zuelzer
1982,
pp.
27-28.
[82 545,
82
544].
April
10
Submits the
expanded
version
of
his lecture
(of
February
19)
on Ampère’s
molecular
currents,
"Experimental
Proof
of
Ampère’s
Molecular Currents"
(with
W.
J. de
Haas)
(Vol.
6,
Doc.
13).
April
16-August 15
Lectures
on
the
theory
of
relativity
at
the
University
of
Ber-
lin,
Thursdays,
2-4
P.M.
Provenance: Berlin
Verzeichnis
1915a.
April
23
"Experimental
Proof
of the Existence
of
Ampère’s
Molecu-
lar
Currents"
(with
W. J.
de
Haas)
(Vol.
6,
Doc.
14).
May
7 "Experimental
Proof
of
Ampère’s
Molecular Currents"
(Vol. 6,
Doc.
15)
appears
in Die
Naturwissenschaften.
May
10
"Correction
of
My
Joint
Paper
with J.
W.
de Haas:
‘Experi-
mental
Proof
of
Ampère’s
Molecular Currents’"
(Vol. 6,
Doc.
16).
May
14
The
Dutch
version
of
the
Ampère
current
paper
is
pub-
lished. Reelected
member of
the
advisory
committee
of
the
DPG. Provenance: Deutsche
Physikalische Gesellschaft.
Verhandlungen
17 (30
May
1915),
no. 10, p.
190.
May
18
1-page
TTrL
to
Kgl. Landgericht I,
Berlin. In the
matter
of
Anschütz
vs. Sperry,
Einstein
agrees
to
attend
a
test
experi-
ment to
determine whether the
Sperry compass infringes on
Anschütz’s
patent. Appended
is the
response
in
transcrip-
tion
by
Dr.
Berghoff, presumably
of
the
court,
confirming
Einstein’s
comments. Provenance:
GyKiRA, Aco,
Gruppe
IIa, Mappe
555/a.
[83 489, 83 490].
ca.
June Becomes member
of
the Bund "Neues Vaterland."
June 2 Conference
on relativity
of
the
Verein
von
Freunden
der
Treptow-Sternwarte
at the
Berlin-Treptow Observatory.
Einstein’s lecture "Relativität der
Bewegung
und Gravita-
tion"
is
subject
of
an
article in Vossische
Zeitung (3
June
1915),
Evening
Edition,
p.
2. [79 977].
June
15
"Comment
on
the
Essay
Submitted
by Knapp:
‘The Shear-
ing
of
the Light-Ether...’"
(Vol.
6,
Doc.
17).