Research notes, drafts; final manuscripts; internal reports; reprints. Collection documents Tonks' research at General Electric laboratories on plasmas, ferromagnetism, surface thermodynamics, magnetrons, reactor theory, fusion, and lasers. Subject files include letters, clippings, and reprints on a variety of scientific and personal interests including the impact of the Cold War and of the McCarthy era. Correspondence primarily on business and routine matters also documents his involvement in the preparation for the Conference on Plasma Physics and Controlled Nuclear Fusion Research, 1961. Notebooks (1956 and 1964-1967) kept by Tonks as technical consultant for General Electric. Sound recordings (eight 78 rpm discs and 1 33 1/3 rpm discs, 1948-1953) of the radio series, General Electric Science Forum, written in part by Tonks, as well as a folder of information and material written by Tonks for the forum.