1 9 6 D O C U M E N T S 2 3 8 , 2 3 9 J U N E 1 9 2 2 another such wretch, Mohorovicic. \ \  I wouldn’t have it printed. But if you do find it more convenient than rejecting, that’s all right with me too. Warm greetings, yours, Einstein. 238. From Paul Ehrenfest [Magdeburg,] 17 June 1922. Dear Einstein, In the end it was nice that you accompanied me up to the train. —I otherwise easily feel so “abandoned.” I just want to say one more thing to you: What makes such a meeting with you or Bohr (or such fellows as Busch) so valuable and irre- placeable to me is not that I learn this or that thing (or see it through your eyes) but above all that such a calm force emanates from you. That beneath the hurry-scurry there is a solid ground whose technical units of time are higher, by a respectable number of powers of ten, than those in everyday life—others can find this in nature, I can do so better in a few special people. Most affectionate greetings, yours, P. E. Jo[ffe] came 8 minutes before the train’s departure—to my dismay not alone. Regards to your wife, il[se]-mar-go-tse, and also to Frieda. 239. To Hermann Anschütz-Kaempfe [Berlin,] 18 June 1922 Dear Mr. Anschütz, I am a little worried about the power supply. I do not believe that the hard rub- ber can be enriched enough with carbon powder to conduct properly. It seems that it would be most natural to plate the aluminium sphere with a more precious metal [copper?] at the electrode points and to saturate the solution with a salt of this same metal. Have you already tried that? Or is there any means of applying a layer of graphite? Or is there any chemically impervious insulator (enamel?) that is so thinly coatable that the electrode can be fashioned into a condensor of sufficient capacity? (I estimate that the latter is probably not possible because the layer would have to be almost molecular in thickness.) In any case, this is a serious problem. Maybe platinized platinum would be useful as an electrode I do not know, though, whether the flaking off can be avoided.