D O C . 2 8 1 J A N U A R Y 1 9 2 0 2 3 3 where I call c the local “mother clock.” I introduce “homogeneous velocities” and put, for ex.: : c, etc. As concerns the displacement of the spectrum lines of the Sun, in my o[pinion], absolutely no conclusions can be drawn. Therefore, it is no wonder if observations lead to a negative finding.[8] Earlier, you promised to come and see me but I expected you in vain.[9] It really would have pleased me very much to be able to debate with you in person. I remain, with kind regards, yours truly, E. Guillaume. 281. From Edgar Meyer Zurich 1, 69 Rämi St., 25 January 1920 Dear Mr. Einstein, I thank you very heartily for both your letters.[1] I would very much have liked to have replied earlier but I still wanted to wait for the committee meeting, and that was unfortunately much delayed.[2] Well, I thank you very much for the letters but, of course, the result is very sad for me and for us here. But I did know what you think and I suspected as much.[3] But I was exceedingly happy about the news that you really do want to visit us. I just would like to suggest one small modification, also in my wife’s name. Please come, not with your wife or your daughter, but bring them both along. We have more than enough room in the house and would like you to feel as comfortable here as ever possible. That is why you should please bring wife and daughter along. Any time suits us. Come whenever you wish, but please really do come! I thank you very much for your suggestion in your second letter. I had already thought of something similar myself, as something definitely must be done for Ratnowsky. I hope too that I prepared my colleagues favorably for it, and even in the event that the business were too expensive for the government, I have already arranged the money with which it can be done. However, I had thought that Epstein would receive the full professorship, because otherwise there would be too many problems regarding examinations, the faculty, etc., if it weren’t a full professorhip. Ratnowsky was then supposed to receive the title as well as a secure, well-paid γx dx dt ----- -=