Contributors to this Issue 



George A. Campbell, B.S., Massachusetts Institute of Technology, 

 1891; A.B., Harvard, 1892; Ph.D., 1901 ; Gottingen, Vienna and Paris, 

 1893-96; Mechanical Department, American Bell Telephone Company, 

 1897; Engineering Department, American Telephone and Telegraph 

 Company, 1903-19; Department of Development and Research, 

 1919- ; Research Engineer, 1908-. Dr. Campbell has published papers 

 on loading and the theory of electric circuits, including electric wave- 

 filters, and is also well known to telephone engineers for his contri- 

 butions to repeater and substation circuits. 



C. W. RoBBiNS, Eureka Electric Company, 1901-1905; Western 

 Electric Company; Testing Apparatus Design, 1905-06; Chief of 

 Inspection Methods Division, Chicago, 1906-08; Chief Inspector 

 Cable, Rubber and Insulating Shops, Hawthorne, 1908-18; Assistant 

 Superintendent of Inspection, 1918-27; Assistant Superintendent of 

 Inspection Development, 1927-. Much of Mr. Robbins' work has 

 been connected with gages, testing and measuring apparatus and 

 methods. 



IsLa.rl 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 stu- 

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

 His earlier articles on Contemporary Physics form the nucleus of a 

 recently published book entitled "Introduction to Contemporary 

 Physics" (D. Van Nostrand Company). 



E. Peterson, Cornell University, 1911-14; Brooklyn Polytechnic, 

 E.E., 1917; Columbia, A.M., 1923; Ph.D., 1926; Electrical Testing 

 Laboratories, 1915-17; Signal Corps, U. S. Army, 1917-19; Bell 

 Telephone Laboratories, 1919-. Mr. Peterson's work has been largely 

 in theoretical studies of carrier current apparatus. 



Edward B. Craft, Engineering Department, Western Electric Com- 

 pany, Chicago, 1902-07; Development Engineer, Western Electric 

 Company at New York, 1907-18; Assistant Chief Engineer, 1918-22; 

 Chief Engineer, 1922-25 ; Executive Vice President of Bell Telephone 

 Laboratories, 1925-. 



Mr. Craft's duties have been executive for some years, but he also 

 has many patents and has made outstanding individual contributions, 

 prominent among which is the flat type relay. 



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