Contributors to this Issue 



H. A. Affel, S.B. in Electrical Engineering, Massachusetts Institute 

 of Technology, 1914; Research Assistant in Electrical Engineering, 

 1914-16. American Telephone and Telegraph Company, Engineering 

 Department and the Department of Development and Research, 

 1916-34; Bell Telephone Laboratories, 1934-. As Assistant Director 

 of Transmission Development, Mr. AfTel is concerned with toll trans- 

 mission problems, including the development of carrier telephone 

 systems. 



J. W. Beyer, B.S., State College of Washington, 1915; Westing- 

 house Electric and Manufacturing Company, 1915-16. Instructor in 

 Electrical Engineering, State College of Washington, 1916-19, 

 Western Electric Company, Engineering Department, 1919-24. Bell 

 Telephone Laboratories, 1924-. Mr. Beyer is concerned with the 

 development of carrier telephone terminals and pilot channels for 

 open-wire circuits. 



E. C. Blessing, B.S. in Electrical Engineering, Purdue University, 

 1922, Western Electric Company, Engineering Department, 1922-25 ; 

 Bell Telephone Laboratories, 1925-, Mr. Blessing has been engaged 

 in the development of carrier systems. 



S, I. Cory, B.E.E., Ohio State University, 1916. American Tele- 

 phone and Telegraph Company, Engineering Department and Depart- 

 ment of Development and Research, 1916-1934; Bell Telephone 

 Laboratories, 1934-. During this entire time Mr. Cory has been 

 engaged in transmission development work, chiefly on telegraph 

 systems and transmission-measuring methods. 



Frank A. Cowan, B.S. in Electrical Engineering, Georgia School of 

 Technology, 1919. American Telephone and Telegraph Company at 

 Atlanta, Ga., 1920; Long Lines Engineering Department, Special 

 Service Group, New York, 1922; appointed Division Transmission 

 Engineer, Division No. 1, New York, 1926; appointed to present 

 position. Engineer of Transmission, Long Lines Department, 1928. 



Karl K. Darrow, B.S., University of Chicago, 1911; University of 

 Paris, 1911-12; University of Berlin, 1912; Ph.D., University of 



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