CONTRIBUTORS TO THIS ISSUE 763 



Laboratories, 1926-. Mr. Henning's early Laboratories work was con- 

 nected with the development of high-quality sound recording and re- 

 producing equipment and techniques. During this interval he developed 

 the 9A disc phonograph reproducer. Other pre-war experience included 

 development of telephone voice recorders, noise reduction studies of the 

 dynamics of teletype equipment, and design of coin collector slug rejec- 

 tors and coin disposal relays. During World War II he was concerned 

 with improvements to the sound power telephone, and later with develop- 

 ment of specialized magnetic sound recording- reproducing systems. 

 After the war he resumed his work on high quality sound recording 

 equipment and supervised the design of the 2A lateral disc feedback 

 recorder. More recently he has been concerned with the principles and 

 design of magnetic drum digital data storage and apparatus. He is cur- 

 rently engaged in investigating the application of square hysteresis 

 loop magnetic cores to digital computer systems. 



David, A. Kleinman, S.B. in Chemical Engineering, 1946, S.M. in 

 Mathematics, 1947, Massachusetts Institute of Technology; Ph.D. in 

 physics, Brown LTniversity, 1952. Dr. Kleinman joined Bell Telephone 

 Laboratories at Murray Hill in Jul}^ 1953. Since then he has studied 

 theory of transistor devices and has been engaged in research in the band 



■theory of solids in the Solid State Electronics Research Department. 



I He is a member of the American Physical Society. 



F. J. MoRiN, B.S. and M.S., University of New Hampshire, 1939 and 

 1940; University of Wisconsin, 1940-1941; Bell Telephone Laboratories, 

 1041-. During World War II, Mr. Morin was involved in research on 

 j elemental and oxide semiconductors and the development of thermistor 

 materials. Since that time he has worked on fundamental investigations 

 into the mechanism of conduction in silicon, germanium and oxide semi- 

 -conductors. Mr. Morin is a member of the American Chemical Society 

 and the American Physical Society. 

 i 



0. J. Murphy, B.S. in Electrical Engineering, University of Texas, 

 1927; Columbia University, 1928-31. Bell Telephone Laboratories, 

 1927-. Mr. Murphy's early Laboratories projects included studies of 

 \'oice-operated switching devices, effects of transmission delay on two- 

 Way telephone conversation, and voice-frequency signaling systems. 

 1 )uring World War II he was concerned with design and development of 

 ihe M-9 electrical gun director and related projects. After the war he 

 resumed his research work on signaling systems and more recently has 



