The Karl Taylor Compton Lectures in Astronomy were presented at the Massachusetts Institute of Technology in November, 1959. Although I had not known Karl Compton intimately, I had met him at various meetings. I remember especially a large meeting of the American Association for the Advancement of Science in Minneapolis at which he presided when I gave an account of progress in astrophysics during the first thirty-five years of this century. Compton encouraged me to continue with my own research, and on subsequent occasions he often helped me with his wise counsel. I was, of course, much more closely associated with his brother, Arthur Compton, who served as professor of physics at the University of Chicago during most of the years I spent at the Yerkes Observatory. In the last few years of my directorship at the Yerkes Observatory, Arthur Compton was my immediate superior as Dean of the Division of Physical Sciences, of which the Observatory was a part.
In presenting these lectures, I have chosen a few topics that seemed of interest to me, and I have not made an attempt to cover the whole large field of astronomy. Hence, this book should be regarded as a selection of topics rather than as a complete account of astronomical progress.
I am especially indebted to the Compton Lecture Committee and to its chairman, Professor F. O. Schmitt of the Massachusetts Institute of Technology, who made all the arrangements for me and who made my stay in Cambridge pleasant and interesting.
Green Bank, West Virginia January, 1961 . . .