244 DOCUMENT 211 JULY 1910 Werner Fetz. Gabryela Birencweig Hermann Braune, Assistent. E[mil] Bruggmann cand math. Libert Arnold E[rnst] Dübi Ing. ADS in the hand of Heinrich Lauer (SzZSa, U 110 b .2 (44)). [70 159]. [1]Two months earlier the dean of the Philosophical Faculty of the German University of Prague had transmitted a commission recommendation of Einstein, unanimously approved by the faculty, to Vienna (see Karl v. Kraus to K. k. Ministerium für Kultus und Unterricht, 23 April 1910, Cz-Ar, MKV/R, No. 101, Einstein Dossier, and Doc. 204, note 10). In reaction to the student petition and fearful of losing Einstein to Prague, the Director of the Zurich Department of Education requested that Einstein be given a salary increase from 4500 francs to 5500 francs, so that he "should be bound" ("gefesselt werden sollte") to the uni- versity. It was further pointed out that Einstein's teaching load of six to eight hours exceeded the normal requirement of four to six hours a week for extraordinary professors (see Heinrich Ernst to Regierungsrat, 12 July 1910, SzZSa, U 110 b .2 (44)). Ernst's request was approved two days later (see Aus dem Protokoll des Regierungsrates 1910, no. 1226, 14 July 1910, SzZSa, U 110 b .2 (44)). In a faculty meeting at the end of July, Einstein indicated his willing- ness to remain (see the minutes of the meeting of the Philosophical Faculty II, 28 July 1910, SzZU, AA 10:3). [2]In this context students of theoretical physics should be understood as those registered for coursework in theoretical physics. Fifty-five students and auditors registered for Einstein's courses in the three semesters he lectured at the University of Zurich, while only three students completed dissertations dealing with theoretical topics during this time-one was the signer of this petition, Ernst Dübi (cf. Kontrollbücher über die Honorargebühren, SzZU, Kassa-Ar- chiv, and Promotionen Fakultät Phil. II 1835-1916, SzZU, AA 23:1). Another signer, Hans Tanner, completed his dissertation in theoretical physics at the University of Basel (see Docs. 265 and 293). [3]In May of the previous year the Governing Council of the Canton of Zurich had resolved to create an extraordinary professorship of theoretical physics and to name Einstein to it (see Doc. 154, note 2). [4]A total of fifteen students registered for and eleven audited Einstein's two courses and one seminar in summer semester 1910 (see Kontrollbücher über die Honorargebühren, S.S. 1910, SzZU, Kassa-Archiv). See Doc. 204, note 8, for more details on Einstein's courses in that semester. 211. To Arnold Sommerfeld Zürich. Juli [19] 10. Hoch geehrter Herr Kollege! Ich zögere so lange, bis ich an Sie schreibe, weil ich einerseits sehr gern hätte, wenn Sie in den Sommerferien wirklich nach Zürich kämen,[1] und weil es mir andererseits an Mut fehlt, Sie dazu zu ermuntern. Denn etwas einiger- massen Geschlossenes über die Frage nach der Konstitution der strahlenden