D O C U M E N T 4 6 8 A P R I L 1 9 2 5 7 3 5 468. From Robert A. Millikan [Pasadena,] April 2, 1925 Dear Dr. Einstein: I had expected that both yourself and Dr. Lorentz would spend next winter, from the first of January to the end of March, with us here in Pasadena, but events in Hol- land now seem to make it preferable for Dr. Lorentz to postpone his visit until the following year, namely, the year 1926–27.[1] I have written him that this will be an arrangement to which we can adjust our program, provided it is quite certain that you yourself will be here during January, February, and March of next year, that is 1926. I think that in your last letter you assured me that I might count upon your being here either in the winter of ’26 or the winter of ’27,[2] but Dr. Epstein tells me that he infers from a letter of yours to him that you are planning to be here in ’26, and I am writing now to express the hope that this is indeed your definite plan, and to ask whether we may now definitely count upon your presence at that time. I told you in my preceding letter that we should not ask you to do any lecturing at all at the Institute unless you wished to do so, and you replied that you would be very glad to come here “for purely scientific purposes.” This will be altogether sat- isfactory to us, for we meet three or four times a week for the discussion of prob- lems, and your presence in these discussions and in talking with the research men who are working both in the Institute and Observatory would be of the utmost val- ue. I am writing, however, to ask whether you would prefer to let your contacts with our work be of this wholly informal type, or whether you would prefer to give some lectures to our group of fifty or sixty graduate men. In this latter case, I should like to know about how many lectures you would prefer and upon what general subject you would wish to talk upon. I am writing, also, to make one further inquiry. Dr. Campbell, President of the University of California and Director of the Lick Astronomical Observatory,[3] has written me saying that while you are here in Pasadena it would be a satisfaction to him if you could visit the University of California at Berkeley, also, and perhaps deliver there a few general lectures. I have replied to him that I would write you about his suggestion, which is essentially that you spend three weeks at the Univer- sity of California after you leave Pasadena about the 20th of March and give say five lectures to their group of graduate students in physics and mathematics upon a subject of your own choosing, and one general lecture before a public university meeting, the honorarium to be $1,000. It is of course understood that this would be