Contributors to this Issue 



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. 



John Davidson, Jr., B.E., Tulane University, 1906; E.E., Cornell 

 University, 1909. Testing Department, General Electric Company, 

 1906-07; Construction Department, AUis Chalmers Company, 1907- 

 1908; Electrical Department, Carnegie Steel Company, 1909-11; 

 American Telephone and Telegraph Company Engineering Depart- 

 ment, 1911-19, and the Department of Development and Research, 

 1919-. Since 1911 Mr. Davidson has been engaged in equipment de- 

 velopment work and is now engaged on toll switchboard and signaling 

 arrangements. 



P. G. Edwards, B.E.E., Ohio State University, 1924; Western 

 Union Telegraph Company, Traffic Department, 1919-21, Plant 

 Department, 1921-22; American Telephone and Telegraph Company, 

 Long Lines Plant Department, 1922-24; Department of Development 

 and Research, 1924-. Mr. Edwards has been engaged in the de- 

 velopment of toll test board equipment and toll test board methods. 



H. W. Herrington, Washburn College, 1918-21; B.S. in E.E., 

 University of Kansas, 1923; E.E., University of Kansas, 1926; 

 American Telephone and Telegraph Company, Department of De- 

 velopment and Research, 1923-. Mr. Herrington has been engaged 

 in the development of toll test board equipment and toll test board 

 methods. 



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

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

 mathematics. University of Chicago, 1917; Engineering Department 

 Western Electric Company, 1917-24; Bell Telephone Laboratories, 

 Inc., 1925-. Mr. Darrow has been engaged largely in preparing 

 studies and analyses of published research in various fields of physics. 



184 



