Memories of Ewald

Dear Editor

Cruickshank's monograph on Ewald and his Dynamical Theory of X-Ray Diffraction brought a flood of memories of Ewald. My first contact with him came in Germany. After visiting Schoenflies in Frankfurt in 1923, I went on to Stuttgart to meet Ewald for the first time. His book Kristalle und Roentgenstrahlen was about to appear and my The Structure of Crystals was in the hands of its publisher. We exchanged copies in due course. He was an editor of the Zeitschrift für Kristallographie and suggested that some of my work be published in it. From then until my laboratory at the Rockefeller Inst. was closed I published in the Zeitschrift with his encouragement.

After WWII I was visited in my laboratory at the NIH by Bernal who was passing through Washington, D.C. I had become involved in seeking biological uses for the new electron microscope and when he saw photographs I was getting of virus crystals, he urged me to show them at a meeting in London being organized to bring together crystallographers who had lost contact over the War years. There I found myself in the midst of the efforts being made, largely by W. L. Bragg and Ewald, to set up what later was to become the International Union of Crystallography. As a senior American crystallographer I participated in the planning and when the Union was accepted by ICSU, I, as a member of the committee of the US National Research Council became active in Union affairs. From the start publication was a major activity of the Union. Acta Crystallographica soon replaced the old Zeitschrift. Ewald became Acta's first editor and I was one of three subeditors. My wife and I had tea with the Ewalds in their Ithaca home a couple of years before his death. Though our common interest in X-ray crystallography dealt with different aspects of its development, our shared appreciation of its importance caused each of us to devote much time and effort to the dissemination of the knowledge it was yielding.

Dr. Wyckoff, born in 1897. was President of the American Crystallographic Association in 1951.