146 BELL SYSTEM TECHNICAL JOURNAL 



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

 Princeton, 1912-14; American Telephone and Telegraph Company, 

 Engeneering 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. 



J. J. Gilbert, A.B., University of Pennsylvania, 1909; Harvard, 

 1910-11; Chicago, 1911-12; E.E., Armour Institute, 1915; in- 

 structor of electrical engineering, Armour, 1912-17; Captain Signal 

 Corps, 1917-19; Engineering Department, Western Electric Com- 

 pany, 1919, since when he has worked on submarine cable problems. 



I. B. Crandall, A.B., Wisconsin, 1909; A.M., Princeton, 1910; 

 Ph.D., 1916; Professor of Physics and Chemistry, Chekiang Pro- 

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

 Company, 1913-. Dr. Crandall has published papers on infra-red 

 optical properties, condenser 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. 



Donald MacKenzie, A.B., Johns Hopkins, 1908, A.M., 1911; 

 Ph.D., 1914; assistant astronomy, 1914-17; associate physicist. 

 Bureau of Standards, 1918-20; Engineering Department, Western 

 Electric Company, 1920-. 



Harvey Fletcher, B.S., Brigham Young, 1907; Ph.D., Chicago, 

 1911; instructor of physics, Brigham Young, 1907-08; Chicago, 

 1909-10; Professor, Brigham Young, 1911-16; Engineering Depart- 

 ment, Western Electric Company, 1916-. The present paper by Dr. 

 Fletcher gives some of the results of an investigation which is being 

 made of the relation between the frequency characteristics of tele- 

 phone circuits and the intelligibility of transmitted speech. Dr. 

 Fletcher has also published on Brownian movements, ionization and 

 electronics. 



