D O C U M E N T 4 1 5 F E B R U A R Y 1 9 2 9 3 7 9 415. From the Hebrew University of Jerusalem [Jerusalem, 26 February 1929] Dear Professor, The University of Jerusalem presents its respectful good wishes on the occasion of your fiftieth birthday. On this day we want to express our great admiration for you as a scientist and our most sincere gratitude to you as a man and a Jew. As a researcher you have opened up unsuspected relationships and facts to sci- ence. The continuity principle, which connects the most extreme molecular dimen- sions in a unity, and the law named after you concerning the quanta absorption of radiant energy in the course of its transformation, are not only landmarks in new domains of physics, but also intellectual bridges of inestimable import. The special and the general theory of relativity gave science not only physical knowledge of the deepest imaginable kind, but also set the pattern for scientific thought itself and for the present and future cognitive achievements of the human race. While your name as a scientist is celebrated by the whole world, by all scientific institutions and universities alike, our nascent university also owes you the expres- sion of our greatest gratitude. Right after the war, when the idea of the university began to take its first form, you immediately expressed your support and interest, and later did not shrink from undertaking long trips in order to make the idea of the university a reality you were the first teacher who gave a lecture at our university. Thus your name is intimately bound up with the university, which is proud that its mathematics and physics institute bears your name. Today, our dearest wish is that you, revered professor, will continue to support our university with your advice and help. May the shining example of a Jewish scientist that you have set in loyal fidelity to your people and unfailing devotion to research light the way for all coming gen- erations of teachers and students at the University of Jerusalem. Prof. A. Fodor, Prof. J. Kligler, Prof. S. Adler, Prof. J. Klausner, Prof. J. N. Epstein, Prof. L. Ginzberg, Prof. L. Roth, Prof. O. Warburg, Ch. N. Bialik, S. Ginzberg, Dr. L. Mayer, Dr. G. Schalom, Dr. S. D. Goitein, Dr. H. Baneth, L. Billig, Dr. J. Rivlin, Dr. M. Schwabe, Dr. H. Pflaum, Dr. H. Bergmann, Dr. J. Joel, Dr. Z. Disendruk, Rabbi S. Assaf, M. Ussishkin, N. Bentwitch, Dr. J. L. Magnes, Dr. A. Rupin, Rabbi M. Segal, Dr. A. Tcherikover, S. Malkova, Dr. A. Gulak, Dr. M. Weizmann, Dr. M. Bobtelski, Dr. A. Reifenberg, Dr. M. Fekete, Dr. B. Amira, Dr. M. Frankel, Dr. F. S. Bodenheimer, Dr. G. Fraenkel, Dr. O. Theodor, Dr. L. Ulizki, Ing. Müller, R. Komerova, Dr. S. Samburski, Ch. Epstein, M. Aschner, Dr. A. Rosenberg, Dr. L. Sukenik, R. Schönfeld.