W 30              

Berlin            

April 24, 1920

Dear Solovine,

I am very glad to learn that you intend to write something about my theory. I myself have prepared a summary which I am sending to you; aside from that, I have only the original drafts of essays that are, unfortunately, out of print. Books which I recommend for scientific libraries are Weyl’s Time, Space, Matter and Schlick’s Space and Time in Physics Today (both published by Springer, Berlin), along with another volume entitled The Principle of Relativity and published by Teubner; the third edition of the latter work, soon to appear, will contain the most important of the original essays on the general theory of relativity. I will be glad to read through your manuscript.

Mileva is in good health; I am separated from her; the children are with her in Zurich, Gloriastr. 59. Albert is quite robust; the little one is unfortunately rather sickly.

Besso has roamed through different countries of the world but is again at the Patent Office in Berne. Paul Winteler and my sister are still living happily in Lucerne.

I am very glad to have heard from you again on this occasion; I wish you success in your undertaking.

Best regards from your

A. Einstein