CONTRIBUTORS TO THE JOURNAL 527 



Technology, 1910-12; instructor in physics, Massachusetts Institute 

 of Technology, 1912-14; industrial research work, 1910-14; Western 

 Electric Company, 1914-24; Bell Telephone Laboratories, 1925 — . 

 Mr. Maxfield has engaged in fundamental studies of microphonic con- 

 tacts and electro-acoustic devices. Recently these activities have l)een 

 directed toward the dexelopment of public address systems and meth- 

 ods of recording and reproducing music and speech particularly as re- 

 gards their application to the phonograph and audible motion pictures. 



Henry C. Harrison, A.B., Colortido College, 1910; S.B., Massa- 

 chusetts Institute of Technology, 1913; instructor in electrical en- 

 gineering, Massachusetts Institute of Technology, 1913-14; Western 

 Electric Company, 1914-24; Bell Telephone Laboratories, 1925 — . 

 Mr. Harrison has made fundamental studies of receivers and carbon 

 button microphones. More recently, his work has been principally 

 concerned with the design and development of various mechanical 

 apparatus to embody the principles of electric transmission theory. 



