Contributors to this Issue 



Halsky a. Fki:i)i;rk k, U.S., IViiitcion rni\crsit\-, HUO; K.E., 

 Princeton I'nixersity, 1912; Kngineering Department Western Electric 

 ("()mpan\-, 1912 — . Mr. Frederick has been engaged in research and 

 development problems connected with telephone receivers, trans- 

 milters, and allied siii)jects in the investigation of the transmission 

 and repnidiuiion of sjx-ech and music. 



H. F. DoDci:, S.B., Mass. Insi. Tech., 1916; Instructor in electrical 

 engineering, Mass. Insl. Tech., 1916 1917; A.M. in Physics and 

 Mathematics. Columbia University, 1922; Flngineering Department 

 of Western Electric Company, 1917 — . Mr. Dodge has been engaged 

 ill <ii.-\el()|)ment studies on telephone transmitters. 



fiEORi.i'; .A. ('ami'HICi.i.. B..S., Massachusetts Institute of Tech- 

 nology, 1891; A.B., Harxard, 1892; Ph.D., 1901; C.ottingen, X'icnna 

 and Paris, 1891^ 96; Mechanical Department, American Bell Telephone 

 Company, 1897; Engineering Department, American Telephone and 

 Telegraph Company, 1908 -19; Department of I)e\clopment and 

 Research, 1919 — ; Research Engineer, 1908 — . Dr. Campbell has 

 published papers on loading and the theory of electric circuits, in- 

 cluding electric wa\e-filtcrs, and is also well known to telephone 

 engineers for lii> contribiiiiniis to rejiealor and sulistation circuits. 



JuHN K. C.\KM,\, B.S.. i'rincctdn. 1907; l'..!'... 1909: M..S., 1912; 

 Research Department, Wesiinghouse Electric and Manufacturing 

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

 I'rinceton, 1912 14; American Telephone and Telegraph Compain', 

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

 l-'.ngineering Department, 1918; Department of Dc\elopment and 

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

 lines and he has jiublished sexeral pajiers on theor\ of electric circuits 

 and electric wa\e propagation. 



Otio J. Z()Hi;i„ A.B., Ripon C(>llii.;r. 1909; A.M., Wi-nuisin, 1910; 

 Ph.D., 1914; instructor in ph\sics, 1910 15; instructor in plnsics, 

 Minnesota, 1915-16; Engineering Department, American Telephone 

 and Telegrajjh Company, 1916 19; Department of Development and 

 Research, 1919—. Mr. Zobel has made important contributions to 

 circuit theor\- in branches other than the subject of waNe-filters. 



