2 4 2 D O C U M E N T S 3 1 2 , 3 1 3 J U L Y 1 9 2 2 the right frequency without need for any feedback by the string motions to the cur- rent-producing mechanism. I believe that your regulating method could be applied with success in disparate fields of precision measurement. With utmost respect, A. Einstein. 312. To Hendrik K. de Haas Berlin, 27 July 1922 Highly esteemed Colleague, I fully appreciate the great honor and favor that lies behind the invitation you relayed to me by the Battaafsch Genootschap and the Rotterdam Naturkundig Genootschap. To my great regret I cannot accept this invitation for the following reason: The Society of [German] Scientists and Physicians has its annual convention in September in Leipzig, which is simultaneously the memorial celebration of this society’s 100th anniversary. It had already invited me a year ago to deliver the key- note speech. I had to cancel this speech, for reasons of personal security, as a con- sequence of the agitated local conditions that everyone became aware of through Rathenau’s assassination. It would now, without a doubt, be perceived among the ranks of German scientists as an injury, indeed, a virtual affront if I accepted the keynote speech for an analogous event abroad scheduled for roughly the same time. In asking you to please give this reason full acknowledgment and to convey to the directorate my cordial thanks for the received invitation, I am very sincerely yours. 313. From Chaim Weizmann 27 July 1922 Dear Professor Einstein, Many thanks for your letter of the 17th inst. with reference to your article or introductory note for the New Palestine. I explained that this is a volume dealing with the problems of the new Palestine, and I thought it would be appropriate if you would be good enough to contribute a few words about the university. Its effect on the world at large what you said in America, for example. I should be very glad if you would be good enough to write something on these lines. Kindest regards, yours very sincerely, Ch. W. Translator’s note: Original written in English.