Albert EINSTEIN (1879-1955). P.S., Princeton May 7, 1945; typewritten half-page in-4 on letterhead The Institute For Advance Study, School of Mathematics, Princeton, New Jersey; in English (a little creased). Recommendation in favor of Dr. Joseph CASTEL, eldest son of a close friend of Einstein, whom he knew in Germany; he is also well informed about his life after 1933 and his activities. He knows him to be politically reliable and devoted to the cause of the United Nations. Dr. Castel is an intelligent and skillful man, and a competent physicist...