when the Union was formed. The Committee also nominated him Editor of the journal to be published by the Union. The first issue of Acta Crystallographica was published in 1948, the same year that Ewald chaired the first General Assembly and International Congress of the IUCr, which was held at Harvard University. In 1952, Ewald was elected President of the American Crystallographic Association. He served on the IUCr Executive Committee from its foundation until 1966, and he was its Vice-President in 1957 and President in 1960, a position he held until 1963. His editorship of its journal Acta Crystallographica extended from its inception in 1948 to 1959. A decade after moving to Belfast, Ewald moved to the United States in 1949 and took a position at the Polytechnic Institute of Brooklyn, as a professor and head of the Physics Department. He retired as head of the department in 1957 and from teaching in 1959. Honors 1958 – Fellow of the Royal Society 1978 – Deutsche Physikalische Gesellschaft Max Planck medal 1979 – Gregori Aminoff Prize 1986 – The International Union of Crystallography established the Ewald Prize for outstanding contributions to the science of crystallography. Books Paul Peter Ewald Kristalle und Röntgenstrahlen (Springer, 1923) Paul Peter Ewald, Theodor Pöschl, Ludwig Prandtl; authorized translation by J. Dougall and Winifred Margaret Deans The Physics of Solids and Fluids: With Recent Developments (Blackie and Son, 1930) Paul Peter Ewald Der Weg der Forschung (insbesondere der Physik) (A. Bonz'erben, 1932) Peter Paul Ewald, editor 50 Years of X-Ray Diffraction (Reprinted in pdf format for the IUCr XVIII Congress, Glasgow, Scotland, 1962, 1999 International Union of Crystallography) Peter Paul Ewald On the Foundations of Crystal Optics (Air Force Cambridge Research Laboratories, 1970) See also Ewald summation Ewald's sphere Multiple scattering theory Ewald–Oseen extinction theorem Pendellösung George Doundoulakis Bibliography Durward W. J. Cruickshank, Hellmut J. Juretschke, N.` Kato (editors) P. P. Ewald and His Dynamical Theory of X-ray Diffraction: A Memorial Volume for Paul P. Ewald (Oxford University Press, 1992) Notes References Ewald, P. P., editor 50 Years of X-Ray Diffraction (Reprinted in pdf format for the IUCr XVIII Congress, Glasgow, Scotland, Copyright © 1962, 1999 International Union of Crystallography) Greenspan, Nancy Thorndike End of the Certain World: The Life and Science of Max Born. The Nobel Physicist Who Ignited the Quantum Revolution. (Basic Books, 2005) Jungnickel, Christa and Russell McCormmach. Intellectual Mastery of Nature: Theoretical Physics