Coatsibutors to this Issue Jou Beaseacams, A.B, Triity College (now Duke Univensty), 2905 AM, Columbia Univesity, 190; PRD, 17. Profesor of Praneering, Tenity College, 1909-1012 Resear Anetrt in Paysie, Columbia Uns vwensig, TITAS, Phyaieit, Resort Laboratory, Eastman Kislak Cortes, 1915-1017; Engineering Depaetnent, Wescer Flere Com pny, 1917-1008; Bel Teleshoue Laheratores,1925-. Dr. Blchari's werk hs Ine cancerel primary wis sper ste by eonnetinn wth “he development of vacant ao, Me rene hs en ached tothe Technical Consulting Sta of the Laboratories G. M. Bovrox, ChE, Brooklyn Polstechuie Institute, 1926. Bel Telephone Laboratories, 1926 . Mr Heaton isin charge of © sreup con- ceraed primarily with the metllray of lead cable sheath alloys andecléers snd with genera micrccopi examinstion of metalic materials WB. Mason, BS, in Flectical Ensinesing, Uaiveniy of Keneas, 1921; M.A Colunbia University, 1925; Pa.D., 1928. Bll Telephone LLaborctoln, IEI-, Dr. Mason tus beta eagmged bn aves oa ‘ser spsteis a i wot on wave tabazisson network both eectrcal ‘and mceaaniva. He is now Rea of the department investigating pon ect ental. anes I, Scuowacam, BS., aivenity of Michigan; Reaareh Asie tant in Chemistry, 1916-18, Engimerng Departnene, Western Elewtie Company, 1918-25; Bell Telphone Taboratories, 1925. Ae Associate emarch Metallrgist, Mr. Sehutacher fi charge of + group wast wok elas largely to seer studies on sacs and alloys orcs L Wut, BS. in Hoy Inet Sate Cala 1925, Navth sweeten Bell Tlspicne Cory, 1920 19315 American Telepione onl ‘Telegraph Compary, 1921 1984; Bell Tepoce Lsboratorcs, Ine 1984 {fr Wilkins bas sued principally the applizatin to telephone prob lems af the rathemat ea hry of ply