Dr. Walter Hietsch. Also present was Dr. Ernest A. Lederer, a grandson of Ernst Mach. The contributors, to the symposium, mostly physicists, represented different backgrounds and differing points of view; they presented their review of Mach's work primarily in the light of subsequent developments. They all, however, share a common interest in the life and works of Ernst Mach. Two of them, Otto BlUh and Peter G. Bergmann, received their doctoral degrees in theoretical physics from the University of Prague. Karl Menger received his doctoral degree in mathematics from the University of Vienna (he is responsible for the latest edition [1960] of Mach's celebrated The Science of Mechanics: A Critical and Historical Account of its Development, for which he prepared a new Introduction).