I cannot say how glad we are for the good news about the chancesA for the University post in Copenhagen, and how thankful I am for all what our friends have done for me. I look forward so much to come home and take up the work. We had quite given it up for this year, and it came therefore as a great surprise indeed, as you will have understood from our letters and especially from those about the invitation from the University of California.

Although I had not quite made up my 1v|mind whether it was right to accept it in my age and with my small knowledge, we were beginning to look forward to go, and I wrote to Prof. Lewis and said that I hoped to be able to go, but could not give a definite answer at once, as I was due to return to my post in Copenhagen in September next. I told him that I had written to Copenhagen and hoped to receive a reply in about a fortnight, and that I should answer the University of California definitely as soon as I got a reply from Copenhagen. All the time, however, I thought this only a matter of formality, as I never really expected the professorpost to come this year, and thought I should easily be able, on the invitation to California, to obtain leave from my lectureship.

Now of course the whole question is quite different, and I understand quite well that it may not be possible 2r|to go. I should be so very glad if you as soon as possible would write and tell me what you think about it all, what you would do in such a case, and whether you think it best to refuse the invitation at once. I am so sorry allways to make so much trouble, but I must decide very soon what to answer the Californians.

We are so glad for all mothers letters and do not know how to thank her; I hope you are all well, how shall it be nice all to meet again. I should like so much to hear about your work, and how the book is progressing; how an immense work it must be. How I also wish I could speak to you about my own things. You heard that Sommerfeld has written an exceedingly important paper, which form a generalisation of my speculations, by which it is possible to explain 2v|a very great number of things, f. inst. the fine structure of the hydrogen and helium lines. I had thought a little over it, without being able to solve it, and Evans had made some very interesting experiments about it. Evans has written a letter to “Nature”, and I shall send it in a few days together with a letter to Sommerfeld. I have waited so long because I have worked very hard with an improvement of my paper, which already was in type. I thought I had succeeded in bringing all Sommerfeld’s results into the scheme of my paper, and even to improve them from a certain formal point of view. But then I found a difficulty, which, I think, I suceeded in solving, but which disturbed certain analogies used essentially in my paper. I therefore went down to London on Saturday to speak with the Editor of the Phil. Mag. and to get him to postpone the paper, so that I could really get time to think it all over. At present I do not knowA exactly what to do, not with the matter but with the form of my paper, but next Wednesday my lectures stop for this term and I shall get more time. Now I must end for this time with my kindest regards and our best love to you all. Will you also remember me to all friends you meet (Hansen f.inst). I am dreadfully ashamed not to have written to anybody for a long time, but I have really been very busy. When I 1r|thinkA of it, shame is not an adequate word, for the horror I feel when I get to think of Edgar f.inst; and especially of Ole! Think, I have never written to him, but at first I expected to hear from him, and then I thought it too late to write, and now I am waiting for something “impossible” to turn up to change the situation.