The collection ranges in subject matter from research problems to personal and professional correspondence, and from organizational publications to contemporaneous confidential material. Professional activities include membership and office held in most scientific organizations, public speaking engagements, editorship of publications, official campus visits for associations, etc. His Bryn Mawr materials are also included, as are such physics department materials as financial ledgers, details concerning the Dalton Fire and construction of the Science Building, lecture and laboratory notes, grant proposals, scientific problems, etc. His incoming, outgoing and third-party correspondence involves teaching and research openings at Bryn Mawr and elsewhere; organizational correspondence for American Journal of Physics, American Institute of Physics, American Association of Physics Teachers, CCP, etc.; letters of reference for Bryn Mawr students and others; publications, etc. Correspondents range from famous scientists to individual high school physics teachers. His political activism is included in materials relating to public lectures, lobbying for atomic controls, radio and television presentations, etc.