CONTRIBUTORS TO THIS ISSUE 215 



John R. Carson, B.S., Princeton, 1907; E.E., 1909; M.S., 1912; 

 Research Department, Westinghouse Electric and Manufacturing 

 Company, 1910-12; instructor of physics and electrical engineering, 

 Princeton, 1912-14; American Telephone and Telegraph Company, 

 Engineering Department, 1914-15; Patent Department, 1916-17; Engi- 

 neering Department, 1918; Department of Development and Research, 

 1919-. Mr. Carson is well known through his theoretical transmission 

 studies and has published extensively on electric circuit theory and 

 electric wave propagation. 



Edward C. Molina, Engineering Department of the American 

 Telephone and Telegraph Company, 1901-19, as engineering assistant; 

 transferred to the Circuits Design Department to work on machine 

 switching systems, 1905; Department of Development and Research, 

 1919-. Mr. Molina has been closely associated with the application 

 of the mathematical theory of probabilities to trunking problems and 

 has taken out several important patents relating to machine switching. 



W. P. Mason, B.S., University of Kansas, 1921; M.A., Columbia, 

 1924; Ph.D., Columbia, 1928. Engineering Department, Western 

 Electric Company, 1921-25; Bell Telephone Laboratories, 1925-. 

 Mr. Mason's work has been largely in transmission studies. 



L. G. BosTWiCK, B.S. in E.E., University of Vermont, 1922; Amer- 

 ican Telephone and Telegraph Company, Development and Research 

 Department, 1922-1926; Bell Telephone Laboratories, Inc., Research 

 Department, 1926-. While with the Development and Research 

 Department, Mr. Bostwick's work involved general problems on 

 systems for the high quality transmission of speech and music; since 

 then his work has been largely on loud speakers and loud speaker 

 measuring methods. 



H. A. Frederick, B.S., Princeton, 1910, E.E., Princeton, 1912; 

 Engineering Department, Western Electric Company, 1912-1925; 

 Bell Telephone Laboratories, 1925-. Mr. Frederick is in charge of 

 researches and engineering on telephone transmission instruments. 



Donald Mackenzie, Ph.D., Johns Hopkins University, 1914; 

 Assistant in Astronomy, Johns Hopkins, 1914-17; Ensign, National 

 Naval Volunteers, 1917-1918; Bureau of Standards, 1918-1920; 

 Engineering Department, Western Electric Company, 1920-1925; 

 Bell Telephone Laboratories, 1925-. Engaged since 1922 in the 

 development of a system of sound recording by photographic means. 



H. M. Stoller, E.E., Union College, 1913; M.S. in electrical 

 engineering, 1915; Engineering Department of Western Electric 

 Company, 1914 and 1916-1925; Bell Telephone Laboratories, 1925-. 

 Most of Mr. Stoller's work has dealt with special problems connected 



