550 BELL SYSTEM TECHNICAL JOURNAL 



Mr. Evans' contributions to the present paper were made while still 

 a member of the Laboratories staff. 



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. 



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; 

 Engineering Department, 1918; Department of Development and 

 Research, 1919-. Mr. Carson's work has been along theoretical lines 

 and he has published several papers on theory of electric circuits 

 and electric wave propagation. 



Ray S. Hoyt, B.S. in electrical engineering. University of Wisconsin, 

 1905; Massachusetts Institute of Technology, 1906; M.S., Princeton, 

 1910; American Telephone and Telegraph Company, Engineering 

 Department, 1906-07; Western Electric Company, Engineering De- 

 partment, 1907-11; American Telephone and Telegraph Company, 

 Engineering Department, 1911-19; Department of Development and 

 Research, 1919-. Mr. Hoyt has made contributions to the theory 

 of transmission lines and associated apparatus, and more recently to 

 the theory of crosstalk and other interference. 



