Contributors to this Issue 



H. p. Charlesworth, B.S., Massachusetts Institute of Technology, 

 1905; Engineering Department, American Telephone and Telegraph 

 Company, 1905-19; Equipment and Transmission Engineer, Depart- 

 ment of Operation and Engineering, 1919; Plant Engineer, 1920 — . 

 Mr. Charlesworth has had broad experience in the development of tele- 

 phone equipment and with traffic conditions and the standardization 

 of operating methods and practices. 



G. A. Pennock, B.S., Massachusetts Institute of Technology, 1899; 

 Secretary, Kansas City Bolt & Nut Company, 1899-1901; Chief 

 Draftsman, Weber Gas & Gasoline Engineering Company, Kansas 

 City, Missouri, 1901-1902; Mechanical Superintendent, Rock Island 

 Plow Company, 1902-1900; with Western Electric Company from 

 1906, as Factory Engineer, European Plant Engineer and Technical 

 -Superintendent. 



George Crisson, M.E., Stevens Institute of Technology, 1906; 

 instructor in Electrical Engineering, 1900-10. American Telephone 

 and Telegraph Company, Engineering Department, outside plant 

 division, 1910-14; transmission and protection division, 1914-19; 

 De\elopment and Research Department, transmission development 

 division, 1919 — . 



I. B. Cr.\nd.\ll, A.B., Wisconsin, 1909; A. M., Princeton, 1910; 

 Ph.D., 1910; Professor of Physics and Chemistry, Chekiang Provincial 

 College, 1911-12; Engineering Department, Western Electric Com- 

 pany, 1913-24; Bell Telephone Laboratories, Inc., 1925 — . Dr. 

 Crandall has published papers on infra-red optical properties, con- 

 denser transmitter, thermophone, etc. More recently he has been 

 associated with studies on the nature and analysis of speech which 

 have been in progress in the Laboratory. 



C. F. Saci.\, B.E.E., University of Michigan, 1910; Engineering 

 Department of the Western Electric Company, 1910 24; Bell Tele- 

 phone Laboratories, Inc., 1925 — . Mr. Sacia has been engaged upon 

 niethixls for recording and analysing speech. 



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

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



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