482 BELL SYSTEM TECHNICAL JOURNAL 



P. W. Spence, B.S., Columbia University, 1918; E.E., Columbia 

 University, 1921. American Telephone and Telegraph Company, 

 1921-27; Bell- Telephone Laboratories, 1927-. Since 1927, Mr. 

 Spence has been largely occupied with studies on the effects of electric 

 shock. 



L. R. Wrathall, B.S., University of Utah, 1927; Graduate School, 

 1927-28. Bell Telephone Laboratories, 1929-. Mr. Wrathall has 

 been engaged in the study of non-linear reactances. 



