Contributors to this Issue 



Charles Clos, C.E., New York University, 1927; New York Tele- 

 phone Company, plant extension engineering, valuation and depreciation 

 matters, intercompany settlements and tandem and toll fundamental 

 plans, 1927-47. Pratt Institute, Evening School, Mathematics Instruc- 

 tor, 1946-49. Bell Telephone Laboratories, studies on development plan- 

 ning for local and toll switching systems and research in switching 

 probabiUty, 1947-. Member of A.I.E.E., New York Electrical Society, 

 Mathematical Association of America, A.A.A.S., American Statistical 

 Association, Iota Alpha, and Tau Beta Pi. 



R. H. CoLLEY, A.B., Dartmouth College, 1909; A.M., Harvard Uni- 

 versity, 1912; Ph.D., George Washington University, 1918; Austin 

 Teaching Fellow in Botany, Harvard University, 1910-12; Instructor in 

 Botany, Dartmouth College, 1909-10 and 1912-16; Pathologist, Division 

 of Forest Pathology, Bureau of Plant Industry, U. S. Department of 

 Agriculture, 1916-28. Bell Telephone Laboratories, 1928-52. Dr. Col- 

 ley was chairman of Conamittee 05 — Wood Poles, of the American 

 Standards Association for nearly twenty years. He was president of the 

 American Wood-Preservers' Association 1943-44. During his years with 

 the Laboratories he worked particularly on development and research 

 problems connected with material and preservative treatment specifica- 

 tions for poles and other timber products used in outside plant. His more 

 recent activities were directed toward improvement of laboratory tech- 

 niques for evaluating wood preservatives, and toward the development 

 of a coordinated plan for fundamental research on oil preservatives. He 

 was Timber Products Engineer for the Laboratories from 1940 to 1950, 

 and Timber Products Consultant from 1950 to 1952. His article in this 

 issue of the Journal was prepared before his retirement on May 31, 

 1952. 



Karl K. Darrow, B.S., University of Chicago, 1911. He studied at 

 the Universities of Paris and Berlin in 1911 and 1912, speciaUzing in 

 physics and mathematics; Ph.D., University of Chicago, 1917. He then 

 joined the staff of Bell Telephone Laboratories, at that time known as 

 the Engineering Department of Western Electric Company. Here his 



519 



