D O C S . 3 6 4 – 3 6 6 A P R I L 1 9 2 0 3 0 3 364. To Emil Schwamberger 1 April 1920 [Not selected for translation.] 365. To Ludo Moritz Hartmann [Berlin,] Sunday. 2 April 1920 Esteemed Colleague, First of all, I thank you heartily for having come to see me [1] it was a real plea- sure for me. I hope to meet you again very soon and ask you please to think of me if you are convinced that I could do anything of benefit. Although good-willed, I miss opportunities because I am not in the middle of it. Now to business. I consider Mr. Ehrenhaft the most successful worker among Austria’s experi- mental physicists. He conceived and developed new methods, guided many young people to fruitful work, and was an inspiring influence far beyond his own personal sphere of activity. He is, indeed, a little rigid in his views and probably also a little irascible but these are the obverse of his lively temperament, for which he also has his perseverence and energy to thank. I believe that it would be disastrous for sci- entific life in Vienna in the field of physics if one did not allow this man to develop his powers fully. With the currently unmistakable imbalance in Vienna in favor of theory, an energetic man is needed with a preponderate interest in experiments to correct this imbalance. Ehrenhaft is such a person and he is, to my knowledge, the only one currently in Austria.[2] I give you this brief statement of my opinion without factual justification be- cause the effect of such a decision ultimately can only rely on trust. With cordial regards, I am yours, A. Einstein. 366. To [Paul Nathan] [Berlin,] 3 April 1920 Dear Sir,[1] I am returning the article to you. I approve of the title you chose and the closing paragraph you added.[2] I refrained from describing my own experiences from my