9 2 2 C A L E N D A R O F A B S T R A C T S 1 9 2 6 456. From Reichsministerium des Innern [Berlin,] 12 May 1926 Encloses regulations for the visiting of the Rathenau house and for the use of the library of the Walther Rathenau-Stiftung that have been agreed upon by the directors of the foundation and Mrs. Rathenau. Requests silent approval by members of the board. TLS. [32 829]. 457. From Emil Rupp [Heidelberg,] 14 May 1926 Thanks for Docs. 277 and 279 with the manuscript of Doc. 223. Has performed experi- ments with three arrangements. In setup I, lattices of 0.1, 0.2, and 0.05 mm fineness were used. The dependence of interference on the difference between the arm lengths of the interferometer corresponded to AE’s calculations. The periodic processes of electro- magnetic waves must be connected with periodic processes in the atom, if one does not suppose that light quanta from different atoms can join to produce interference. In ar- rangement II, he used one lens. No interference was observed. In arrangement III, he placed both a lattice and a lens in front of the interferometer, but found no clear result. ALS. [20 395]. 458. To Arthur Korn Berlin, 15 May 1926 In reply to Abs. 452, recommends that Korn visit him for a discussion of the proposed project. AKSX. [44 180]. 459. From Auguste Piccard Brussels, 15 May 1926 They could not take off because of bad weather. The balloon needs to be returned to Antwerp by 30 May. Gives details of the thermal isolation, of the stability of setup during a longer drive, and the balloon’s aerodynamic behavior. There must have been many contradictions in Miller’s experiments at Mount Wilson. ALS. [19 217]. 460. From Heinrich Zangger [Zurich, after 15 May 1926] Frieda Knecht has visited him and reported her family’s medical history. He doesn’t know whether Hans Albert Einstein has visited Frieda’s mother Elise Knecht in order to ascertain whether there exist psychotic tendencies. AE should consult Theodor Schäppi, the Knecht family doctor. Frieda has given permission. Zangger is leaving on 1 July, and since AE is there 10–15 July, they won’t meet. He is not feeling well and must take dig- italis. ALS. Schulmann 2012, p. 428. [40 040]. 461. From Paul Painlevé Paris, 16 May 1926 Has been unable so far to arrange a meeting between scientists of the two countries in May. A reply by Fritz Haber to Henri Muraour sent to the Société de Chimie had pro- voked difficulties. Asks whether AE is free on Saturday 22nd to hear the singer Marya Freund and the pianist-composer Alfredo Casella. It will be as interesting as the perfor- mance in March. ALS. [34 820]. 462. From Allgemeiner Blindenverein Berlin, 17 May 1926 Requests that AE join its honorary board. TLS. [43 280]. 463. From Montague D. Eder [London,] 18 May 1926 Attaches Sigmund Freud’s reply to the congratulatory telegram sent by the BOGHU (see Abs. 439). TLC. [91 432]. 464. From Leo Kohn [London,] 18 May 1926 Chaim Weizmann would like to schedule the meeting of the BOGHU around 17 August in eastern Switzerland or Tirol, where he will be spending his vacation, and hopes this