C H R O N O L O G Y 1 9 2 2 7 7 3 Early April Meets with Walther Rathenau and Kurt Blumenfeld to dis- cuss Palestine and “the Jewish problem.” Blumenfeld 1962, pp. 142–144. April 2 The film on the theory of relativity is first shown at the opening of the Frankfurt Fair. April 3 First session of discussions at the Collège de France. Nord- mann 1922b, pp. 140–152. April 5 Second session of discussions at the Collège de France. Nordmann 1922b, pp. 152–154. April 6 Participates in the discussions of the French Philosophical Society. April 7 Last session of discussions at the Collège de France. Nord- mann 1922b, pp. 156–159 Tägliche Rundschau, 8 April 1922. April 8 Attends the performance of Molière’s L’Avare and Pierre de Marivaux’s Jeu de l’amour et du hasard at the Theatre- Français. Le Petit Parisien, 10 April 1922. April 9 Visits the battlefields Reims and St. Quentin, northeast of Paris. Departs for Cologne. Nordmann 1922a. after April 14 “Four Lectures on the Theory of Relativity” (Vol. 7, Doc. 71) is published. ca. April 16 Meets Erwin Schrödinger for the first time while visiting Zurich (see Edgar Meyer to Paul Epstein, 4 October 1922 [CPT, Paul Epstein Collection, folder 5.60]). April 16 Germany and Soviet Russia sign the Rapallo Treaty, agree- ing to renounce territorial and financial claims against each other, to normalize diplomatic relations, and to cooperate in furthering their economies. April 18–August 15 Offers a two-hour course on the theory of relativity at the University of Berlin. Berlin Verzeichnis 1922. With Max von Laue and Wilhelm Westphal, offers a physics proseminar at the University of Berlin for students of phys- ics and mathematics who have reached the third semester, Thursdays, 2:30–4 P.M. Berlin Verzeichnis 1922. April 29 Arrives in Amsterdam. Attends the meeting of the Royal Dutch Academy of Sciences. Leaves for Leyden. May 13? Leaves Leyden for Berlin.