THE CONTRIBUTORS TO THIS ISSUE 163 



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 

 telephone equipment and with traffic conditions and the standardiza- 

 tion of operating methods and practices. 



R. V. L. Hartley, A.B., Utah, 1909; B.A., Oxford, 1912; B.Sc, 

 1913; instructor in physics, Nevada, 1909-10; Engineering Depart- 

 ment, Western Electric Company, 1913 — . For some time Mr. 

 Hartley has been closely connected with the development of carrier 

 current, telephone repeater, and telegraph systems. 



I. \V. Green, Graduate in Applied Electricity, Pratt Institute, 

 1905; Engineering Department, New York and New Jersey Telephone 

 Company, 1905-7; Engineering Department, New York Telephone 

 Company, 1907-19; Department of Development and Research, 

 American Telephone -and Telegraph Company, 1920 — . Mr. Green 

 has been engaged on foreign wire relations and more recently on the 

 design of subscribers' apparatus and special problems, such as the 

 public address system. 



W. H. Martin, A.B., Johns Hopkins University, 1909; S.B., 

 Massachusetts Institute of Technology, 1911. American Telephone 

 and Telegraph Company, Engineering Department, 1911-19; Depart- 

 ment of Development and Research 1919 — . Mr. Martin's work 

 has related particularly to loading, quality, and transmission of 

 telephone sets and local circuits. 



Joseph P. Maxfield, S.B. in Electrochemistry, Massachusetts 

 Institute of Technology, 1910, assistant instructor in Electrochemistry, 

 1910-12; instructor in Physics, 1912-14; Engineering Department, 

 Western Electric Company, 1914 — . In addition to being closely in 

 touch with the development of loud speaker systems, Mr. Maxfield's 

 work has covered the fundamental study of microphonic contacts. 



A. B. Clark, B.E.E., University of Michigan, 1911; American 

 Telephone and Telegraph Company, Engineering Department, 1911— 

 19; Department of Development and Research, 1919 — . Mr. Clark's 

 work has been connscted with toll telephone and telegraph systems. 



