Physicist and director, National Bureau of Standards. Correspondence, memoranda, minutes, agenda, reports, studies, congressional testimony, writings, speeches, conference papers, university teaching and training course records, research data, printed matter, and photographs documenting Astin's career at the National Bureau of Standards, 1928-1969.

United States naval officers. Correspondence, memoranda, memorablia, newspapers, notebooks, pamphlets, publications, and speeches relating to the naval careers of Royal Rodney Ingersoll and Royal E. Ingersoll, father and son.

United States Army officer, engineer, and ordnance expert. Correspondence, travel and other diaries and journals, and miscellaneous papers of Mordecai and his family.

Collector of naval history. Correspondence, biographical data on American and foreign naval officers, newspaper and magazine clippings, illustrations, photographs, commissions, autographs, pamphlets, and notes collected by Powel about naval history.